Irrigation Systems Auditing Guide

Efficient Irrigation Management Tools for Agricultural Cultivations and Urban Landscapes IRMA

Irrigation Systems Auditing

Guide

WP5, Action 5.1.

Deliverable 6

www.irrigation-management.eu

Front page back [intentionally left blank]

IRMA info

European Territorial Cooperation Programmes (ETCP)

GREECE-ITALY 2007-2013 www.greece-italy.eu

Efficient Irrigation Management Tools for Agricultural Cultivations and Urban Landscapes (IRMA)

www.irrigation-management.eu

IRMA partners

LP, Lead Partner, TEIEP

Technological Educational Institution of Epirus

http://www.teiep.gr, http://research.teiep.gr

P2, AEPDE

Olympiaki S.A., Development Enterprise of the Region of Western Greece

http://www.aepde.gr

P3, INEA / P7, CRA

Ιnstituto Nazionale di Economia Agraria

http://www.inea.it

P4, ISPA-CNR

Consiglio Nazionale delle Ricerche - Istituto di Scienze delle Produzioni Alimentari

http://www.ispa.cnr.it/

P5, ROP

Regione di Puglia

http://www.regione.puglia.it

P6, ROEDM

Decentralised Administration of Epirus–Western Macedonia

http://www.apdhp-dm.gov.gr

Deliverable 5.1.6. Audit Guide

Involved partners:

TEIEP (LP)

Authoring team: Support team:

Dr. Tsirogiannis Ioannis L. Dr. Myriounis Christos

Dr. Chalkidis Iraklis Mr. Giotis Demetrios

Dr. Papanikolaou Christos Mrs. Baltzoi Penelopi

Mrs. Fotia Konstantina

Place and time:

Arta, 2015

European Territorial Cooperation Programmes (ETCP) GREECE-ITALY 2007-2013 www.greece-italy.eu Efficient Irrigation Management Tools for Agricultural Cultivations and Urban Landscapes (IRMA) www.irrigation-management.eu

Publication info

WP5: Irrigation management tools

Deliverable 5.1.6. Audit Guide

ISBN 978-618-80909-9-6

The work that is presented in this ebook has been co- financed by EU / ERDF (75%) and national funds of Greece and Italy (25%) in the framework of the European Territorial Cooperation Programme (ETCP) GREECE-ITALY 2007-2013 (www.greece-italy.eu): IRMA project (www.irrigation-management.eu), subsidy contract no: I3.11.06.

Disclaimer

Recommendations and projections from this technical guide are based on mathematical models and their accuracy depends upon the quality of measurements and data provided by each individual user. Projections of water use and computed irrigation schedules should always verified and calibrated against actual conditions. The IRMA project and all the linked legal entities and persons make no warranty, implied or expressed, as to the results obtained from these procedures.

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Notes

Contents

Introduction ...... 15 Irrigation and drainage systems ...... 19 Irrigation in Greece and Italy ...... 25 Efficiency in various levels and factors that affect it ...... 27 Efficiency at basin and scheme level ...... 28 Efficiency at end-user level ...... 31 Fiscal returns that are expected from audits ...... 35 Relevant legislation, standards, guidelines etc...... 37 Relevant books, software, training sessions and certification exams ...... 39 Auditors and providers of irrigation auditing services ...... 41 What is an irrigation auditor? ...... 41 Audits in the framework of IRMA project ...... 43 A bit of theoretical background ...... 45 Soil, soil water and roots ...... 45 Plant water needs ...... 46 Irrigation system design and construction ...... 48 Irrigation system management / scheduling ...... 51 Application efficiency ...... 54 Distribution uniformity ...... 55 Audits of irrigation and drainage components at factory ...... 55 Evaluation of uniformity during the design process ...... 57 Evaluation of precipitation rate and uniformity after installation of the system ...... 58 Distribution uniformity indices ...... 59 Modified Interquartile Ratio (MIR) ...... 59 Christiansen’s Coefficient Uniformity (CU) ...... 59 Lower half and Lower quarter Distribution Uniformity indices (DU) ...... 59 Scheduling Coefficient (SC) ...... 60 Statistical Uniformity (Us) ...... 61 Design Emission Uniformity or Emission Uniformity (EU) ...... 62 Accuracy of estimates ...... 63 Design and operation parameters that influence uniformity ...... 64 Auditing of irrigation systems ...... 67 What is and what can we expect from an irrigation and drainage system audit ...... 67 Audits at irrigation scheme level ...... 68 End-user level (farm, municipal landscape, private landscapes of various sizes) ...... 68 Organisation of an audit team (people and infrastructure) ...... 71 Personnel ...... 71 Staff time requirements for irrigation systems audit ...... 71 Equipment and Materials ...... 71 Software ...... 74 SPACEPROTM ...... 74 CROPWAT & ETo Calculator ...... 75 AQUACrop ...... 75 USDA Soil Texture Calculator ...... 76 UC Davis BIOmet Irrigation Scheduling ...... 76 NETAFIM HydroCalc ...... 76 Irrigation Association’s Calculators ...... 76 Solar Energy Calculators ...... 77 Irrigation Cost Calculator ...... 77

Rainbird on line Calculators ...... 77 Performing an audit at end-user level – a step by step presentation using the IRMA workbook ...... 79 Structure and general instructions ...... 79 Α, B, C: Basic system characteristics, system operation evaluation and uniformity measurements82 The “Start audit” worksheet ...... 82 The “Site and System characteristics” worksheet ...... 84 The “Legislation” worksheet ...... 89 The “Zones Stations characteristics” worksheet ...... 90 The “Uniformity test” worksheet ...... 95 Water quality, quantity and pressure measurements ...... 102 The “Uniformity test” worksheet for the special case of travelers ...... 103 D: Data analysis and report generation ...... 107 The “ Substrate and Water” worksheet ...... 107 The “ Uniformity” worksheet ...... 108 The “Climate Irrig Period ETo” worksheet ...... 109 The “Sprinkler schedule” worksheet ...... 111 The “ Micro schedule” worksheet ...... 114 The “ Hydroponic schedule” worksheet ...... 115 E: Final activities ...... 116 The “Report for system manager” worksheet ...... 116 The “System manager diary up to next” worksheet ...... 117 The “Internal Form Audit Cost” worksheet ...... 118 Conclusions, proposals and future trends ...... 119 References ...... 120 Books, guides, reports and papers ...... 120 Standards ...... 127 Annex I Basic units and conversion factors ...... 133 Converting ml to mm of irrigation ...... 134 Online conversion tools ...... 134 Annex II End-user level audit workbook ...... 135 Annex III Application example ...... 136

Tables

Table 1 Expected application efficiency for agricultural applications (Brouwer and Prins, 1989) ...... 31 Table 2 Guidelines for irrigation management (IA, 2007a and b) ...... 53 Table 3 Distribution Uniformity (DUq) and expected efficiency of the system (Beard and Kenna, 2008)...... 60 Table 4 Micro-irrigation system uniformity classifications based on emitter discharge rates (ASAE, 2003b) ...... 62 Table 5 Recommended classification of manufacturer’s coefficient of variation (Cv) ...... 63 Table 6 Recommended ranges of design emission uniformity (EU) ...... 63 Table 7 Confidence limits (90% level) on statistical uniformity estimates (ASAE, 1996) ...... 64 Table 8 Typical irrigation water losses ...... 65 Table 9 Equipment for audit teams ...... 72 Table 10 Values for soil characteristics (FC, WP from USA Soil Texture Classification from FAO p56; Basic if from FAO Tm5 - Brower et al., 1985) ...... 90 Table 11 Water quality for agriculture (Ayers et al., - FAO, 1994) ...... 108 Table 12 Representative days for each month for the calculation of average daylight duration and solar radiation for latitudes between -60o and 60o (Koutsoyiannis and Xanthopoulos, 1999) ...... 110 Table 13 Recommended leaching fractions (Newman, 2008) ...... 113

Figures

Fig. 1 Assessment of irrigation requirements in European countries (Wriedt et al., 2008) ...... 15 Fig. 2 Audit levels and sectors ...... 16 Fig. 3 Variability of priorities and concerns among the various levels ...... 16 Fig. 4 Water Use Efficiency and Water Productivity (Bos et al., 2005) ...... 17 Fig. 5 Schematics of an irrigation system (Brouwer et al., 1985) ...... 19 Fig. 6 Surface irrigation of onions (furrow system) ...... 20 Fig. 7 Big gun irrigation at corn field (Louros, Preveza, 2015) ...... 20 Fig. 8 Sprinkler irrigation for turfgrass (rotor pop-up sprinklers in a golf field) ...... 21 Fig. 9 Overhead irrigation of turfgrass (Megali Toumba, Vergina archaeological site, 2015) ...... 21 Fig. 10 The right thing: a droplet of water -having almost zero relevant pressure- leaves the dripper22 Fig. 11 Young kiwi fruit orchard, irrigated using micro-sprinklers (Kompoti, Arta, 2015) ...... 22 Fig. 12 Micro irrigation of tomatoes (drippers in hydroponic greenhouse) ...... 23 Fig. 13 Open drainage canal ...... 23 Fig. 14 Drainage ditch in turfgrass (drainage tubes are installed in the ditch surrounded by gravel) .. 24 Fig. 15 Drainage canals affected by agricultural activities trash and chemicals (IRMA pilot audits, Arta, 2014) ...... 24 Fig. 16 Open irrigation canal at Arta plain constructed in 2013 (IRMA pilot audits, Arta, 2014)...... 29 Fig. 17 Installation fault, the hydrocyclone cannot operate, sand is passing in the system and the sprinkler nozzles require frequent replacement (photo from IRMA pilot audits, 2014) ...... 32 Fig. 18 Great water losses - very poor efficiency of a municipal irrigation system (photo from IRMA pilot audits, 2014) ...... 33 Fig. 19 Various maintenance problems (photo from IRMA audits, 2014) ...... 34 Fig. 20 Irrigation while raining. In areas with rains during the irrigation period, an auditor could recommend the installation of a rain sensor which could save a lot of water (Peta, Arta, 2015) ...... 35 Fig. 21 Mobile Irrigation Laboratory and relevant training (UF/IFAS Extension, 2014) ...... 41 Fig. 22 Region of Apoulia (Italy) and Region of Epirus and Western Greece (Greece) (source: Google Earth) ...... 43

Fig. 23 Audits in the framework of IRMA project at the Region of Epirus / Greece (photos from IRMA audits, 2014) ...... 43 Fig. 24 The soil texture triangle showing the 12 major textural classes (USDA, 2014) ...... 45 Fig. 25 Basic soil water parameters ...... 46 Fig. 26 Water retention and hydraulic conductivity curves for hydroponic substrates (Raviv et al. 2002) ...... 46 Fig. 27 Basic model of water needs calculation (FAO p56, Allen et al, 1998) ...... 47 Fig. 28 Screenshot from CROPWAT, the FAO software which applies FAO paper 56 procedures ...... 48 Fig. 29 A typical micro-irrigation system ...... 49 Fig. 30 Solid set sprinkler system layout (USDA, 1997) ...... 49 Fig. 31 A springer irrigation system for a football field (Rainbird, 2014) ...... 50 Fig. 32 Basic concepts of irrigation scheduling ...... 51 Fig. 33 Weekly soil water content fluctuation because of irrigation ...... 53 Fig. 34 Daily variation of water content (WC) and electric conductivity (EC) at the substrate of a hydroponic cultivation (Lee, 2010) ...... 54 Fig. 35 Irrigation uniformity and effects on plant's growth ...... 54 Fig. 36 Soil moisture distribution in a rockwool slab after an irrigation event (Bougoul and Boulard, 2006)...... 55 Fig. 37 Factory test of Hunter MPR (Hunter Industries) ...... 56 Fig. 38 Relationship between precipitation rate and distance (left) and relationship between operating pressure, distance and profile (right) for various sprinklers ...... 56 Fig. 39 Emitter pressure - discharge relation ...... 57 Fig. 40 A densogram with indications of the wettest (green square) and the driest (red square) areas (screenshot from SPACEPROTM) ...... 57 Fig. 41 Irrigation auditing catch-cans ...... 58 Fig. 42 Alternative containers used as catch-cans ...... 58 Fig. 43 SC for a specific sprinkler model ...... 61 Fig. 44 A continuous improvement circle ...... 67 Fig. 45 IRMA audit tool case ...... 73 Fig. 46 Indicative screenshots from SPACE PROTM software ...... 75 Fig. 47 CROPWAT logo ...... 75 Fig. 48 AQUACrop logo ...... 75 Fig. 49 A good relationship with the farmer / irrigation manager is a “sine qua non” parameter of a successful audit ...... 80 Fig. 50 Basic system layout (“Site and System characteristics” worksheet) ...... 85 Fig. 51 Filter selection quick reference (IA, 2007b) ...... 88 Fig. 52 Generic zone sketch (system zoomed in at zone scale) and sketch of football field irrigation and drainage system ...... 91 Fig. 53 This catch-can proved to be very small for the discharge rate of micro-sprinklers of that system. This means a lot of wasted hours (Kolomodia, Arta, 2014) ...... 95 Fig. 54 Generic Zone sketch (system zoomed in at zone scale). Instead of the table you can use the boxes to note catch-can number, volume, moisture around etc.for each catch-can location...... 97 Fig. 55 Typical catch-cans placement for a football field. Instead of the table you can use the boxes to note catch-can number, volume, moisture around catch-cans etc...... 98 Fig. 56 Head / flow couples at water source and relevant linear regression line ...... 103 Fig. 57 Traveler audit data (Irrigation New Zealand, Sustainable Farming Fund, Page Bloomer Associates Ltd, 2010) ...... 105 Fig. 58 Indicative omvrothermic diagram (Bagnouls-Gaussen diagram from Nassi o Di Nasso et al., 2013) of Arta Greece (based on climatic information from the Hellenic National Meteorology Service) ...... 110 Fig. 59 Screen shot of the IRMA audit MS Excel work book ...... 135

Equations

Eq. 1 Basic definition of irrigation efficiency (IE) ...... 27 Eq. 2 Precipitation Rate ...... 50 Eq. 3 Relationship between emitter operating pressure and flow rate ...... 56 Eq. 4 Christiansen’s Coefficient Uniformity (CU) ...... 59 Eq. 5 Lower half and the lower quarter distribution uniformity index (DU) ...... 59 Eq. 6 Scheduling coefficient (SC) ...... 60 Eq. 7 Statistical uniformity (Us) ...... 61 Eq. 8 Emission uniformity (EU) ...... 62 Eq. 9 Coefficient of variation (Cv) ...... 62 Eq. 10 Zone flow estimation ...... 109 Eq. 11 ETo (Penman-Monteith) ...... 110 Eq. 12 ETo (Hargreaves – Samani) ...... 110 Eq. 13 Irrigation dose ...... 111 Eq. 14 Irrigation frequency ...... 111 Eq. 15 Irrigation duration (run time) ...... 112 Eq. 16 Irrigation amount (hydroponic schedule) ...... 115 Eq. 17 Crop transpiration (hydroponic schedule) ...... 115

Notes

Introduction When the discussion has to do with an irrigation system we should always have in mind the couple irrigation - drainage and the objective of such a system is to deliver water to the area, implement the right amount of water in the root zone with an appropriate rate and at the right time while it has to be capable of removing the excess quantity of water from the soil when this is necessary. A basic goal of an irrigation manager is to apply water with the maximum possible efficiency. This mission is not easy and it is much more important when we have to irrigate under water scarcity conditions, which is a typical case for countries around the Mediterranean Sea (Fig. 1). When the less possible quantity of the water is used to replenish losses and keep soil water content at a desirable level, then the best possible irrigation efficiency is achieved. This definition can be applied to all levels from end-user to irrigation scheme and hydrological basin (Fig. 2). A major difference between the various levels is that for the last two the losses of one system could be the gains of another. Another difference is that the various levels have probably different priorities and concerns (Fig. 3).

Fig. 1 Assessment of irrigation requirements in European countries (Wriedt et al., 2008)

A tool that can help to increase irrigation efficiency is the periodical audit of relevant systems. The importance of irrigation systems’ audits is expressed by the large volume of relevant research work that has been developed during the last decades. This work along with a number of relevant national and international standards, are used as base in order to prepare practical audit guidelines. During the last 20 years, training manuals, courses and certification exams have been developed by relevant

15 professional agencies mainly in U.S.A. by the Irrigation Association1. In Europe, the European Irrigation Association2 began lately an effort to develop relevant activities.

Fig. 2 Audit levels and sectors

Fig. 3 Variability of priorities and concerns among the various levels

1 http://www.irrigation.org/ 2 http://irrigationeurope.eu/

Irrigation efficiency at end user (farm, landscape setup etc.) can be estimated using direct and indirect methods.

Benchmarking is “a systematic process for securing continual improvement through comparison with relevant and achievable internal or external norms and standards”. Experience from irrigation benchmarking studies has shown that the best results come from using it over a 3-5 year period or even longer (Knox et al., 2012). Water Use Efficiency or Water Productivity is found at the basis of most of the indicators utilized in benchmarking procedures (Fig. 4, Bos et al., 2005). A typical form of WUE (Water Use Efficiency, units: m/v) is given by the ratio Y/IRv, where Y is the yield (expressed in dry matter per unit of area, kg m-2) and IRv is the applied water (mm). Numerous other expressions are available (Bos et al., 2005).

Fig. 4 Water Use Efficiency and Water Productivity (Bos et al., 2005)

Irrigation application efficiency is the ratio of water delivered at the irrigation system start point to the amount stored in the active root zone and is available for use by the plants. Irrigation application efficiency depends on 3 key factors: a) design; b) installation and c) management (which involved both scheduling and maintenance). A very common approach to assess irrigation application efficiency is the Distribution or Outlet Discharge Uniformity. This cannot be considered identical to efficiency, but it provides a sense of the system efficiency level under the condition that adequate management is applied (Burt et al., 1997; IA, 2007).

An audit scopes to increase system's performance by proposing improvements for infrastructure or/and management. Irrigation efficiency at basin / scheme level is a challenge to measure as the losses of one user could be the gains of another. Improvement in system operation after an audit is expected to be immediate.

The present guide targets mainly to the audit of end-user irrigation systems but it also provides basic auditing background regarding higher level irrigation and drainage systems. The goals could be synopsized to the following:

• Acquire basic knowledge of the theoretical aspects regarding audits and the expected benefits from them

• Get familiar with the methodology for conducting an irrigation and drainage system audit:

o Interview and field measurements laboratory analysis and office work for the analysis of the results and the report generation

o communication of results

Irrigation and drainage systems Irrigation science describes the process of calculating and applying the amount of water that plants need at the rate and at the time they need it in order to fulfill the goals they are cultivated for (agricultural production, recreational use, soil erosion avoidance etc). This task is more significant in those areas where water sources are limited and/or rainfall is unevenly distributed over the year. Irrigation and drainage systems are built and operate in order to cover these needs. Each irrigation network is divided into three levels: a) conveyance, b) distribution and c) field application (Fig. 5).

Fig. 5 Schematics of an irrigation system (Brouwer et al., 1985)

Irrigation methods are divided into three main categories: a) surface (Fig. 6), b) sprinkler (Fig. 8) and c) micro irrigation (Fig. 10 and Fig. 12).

Surface irrigation methods are divided into two subcategories depending on whether the soil is flat or not. In the first case, irrigation water is applied to flat soil and it is called basin irrigation. In the second case, irrigation water is applied to non-flat soils where its slope is under 5% and it is called furrow irrigation and border irrigation.

In sprinkler irrigation the water is applied in the form of artificial rain. Usually moving guns and solid set systems are used in sprinkler irrigation when applied to agricultural setups. Spray or rotor pop-up sprinklers are the most common types of outlets for landscaping setups.

Finally micro irrigation applies water in small quantities very close to the roots using outlets that are installed on the ground or bellow soil surface. Drip irrigation is a type of micro-irrigation system in which water leaves the outlet in the form of droplets.

Fig. 6 Surface irrigation of onions (furrow system)

Surface irrigation method is the oldest one. When basin irrigation method is used, the soil is divided into horizontal basins each of them surrounded by low bunts. Those bunts prevent the removal of water to adjacent basins or fields. This method is usually applied to crops that are not affected by the remained to the basin water for a long time. Such crops are rice and orchards. When furrow irrigation is applied, narrow furrows are formed to the soil and through them the water is transported following the slope of the ground. The plants are planted on the banks of each furrow. This method is applied to crops that are sensitive in flood water conditions for a long time. When border irrigation is used, the soil is divided in long strips separated by bunts to prevent the removal of water to adjacent strips or fields.

Fig. 7 Big gun irrigation at corn field (Louros, Preveza, 2015)

Fig. 8 Sprinkler irrigation for turfgrass (rotor pop-up sprinklers in a golf field)

Fig. 9 Overhead irrigation of turfgrass (Megali Toumba, Vergina archaeological site, 2015)

Sprinkler irrigation is a more sophisticated and practical method compared to surface methods. In this case, water is transferred from the source under pressure using closed pipelines. The sprinklers are divided into different categories. Their size varies according to the range of flow they handle and their wetted radius, which classifies them in large, medium and small sprinklers. Finally this kind of system can be applied using irrigation lines where small sprinklers are attached on the irrigation line. Sprinkler irrigation can be applied in almost all open field crops including orchards, turfgrass etc. The water can be applied either over the plant canopy or below it.

Fig. 10 The right thing: a droplet of water -having almost zero relevant pressure- leaves the dripper

Fig. 11 Young kiwi fruit orchard, irrigated using micro-sprinklers (Kompoti, Arta, 2015)

Fig. 12 Micro irrigation of tomatoes (drippers in hydroponic greenhouse)

Nowadays, micro is the most advanced method of irrigation. Micro-irrigation encompasses a number of methods or concepts such as bubbler, drip, trickle, mist or spray and subsurface irrigation. Along the laterals special components, called emitters (or drippers) are attached. There are various types of emitters which can be attached on the laterals or come pre-installed inside the laterals forming driplines or tapes.

Fig. 13 Open drainage canal

The soil porous system supplies oxygen to the root system of the plant. The saturation of the soil may result in reducing the growth of plants. Under saturation conditions the soil porous is full of water, gaseous exchanges with the atmosphere are limited to a few centimeters below the surface and thus the aeration is limited causing root suffocation.

In this case it is also possible certain toxic salts and other organic products (e.g. methane) to be concentrated, a situation which influences negatively the growth of roots and plants.

The term drainage system describes the system that removes the excess soil water and keep the water table (or the free ground water surface) at the desirable level.

Fig. 14 Drainage ditch in turfgrass (drainage tubes are installed in the ditch surrounded by gravel)

Nowadays, the artificial drainage systems consist either of a network of open ditches or a system of closed tubes (Fig. 14). In both cases except of the efficiency of the drainage system to remove excess water a critical issue has to do with the chemicals that drain or run-off water carries with it and the relevant effects on water bodies (Fig. 15).

Fig. 15 Drainage canals affected by agricultural activities trash and chemicals (IRMA pilot audits, Arta, 2014)

All the above mentioned systems can achieve an optimum level of efficiency. Irrigation system’s audits can assist to improve and maintain their efficiency.

Irrigation in Greece and Italy In Greece, the total area of arable land and permanent crops is about 3 and 3.5 Mha (EEA, 2010; FAO-Aquastat, 2015a) and almost 40% of it is irrigated (FAO-Aquastat, 2015a) consuming about 7,000 hm3 (70-80%) of water per year (OECD, 2008; FAO-Aquastat, 2015a). These facts do not include irrigation of urban and recreational landscapes.

Due to uneven rainfall distribution or no rainfall and because a large part of the Greek agricultural production is planted, grown, and marketed during spring, summer and fall (normally the driest part of the year according to the Mediterranean climate), growers of high-per-hectare-value crops find it almost mandatory to provide supplemental irrigation for successful crop production. Besides preventing crop-water stress, irrigation systems are used to protect the crop against heat and cold and to apply fertilizers and pesticides.

Common irrigation sources are the underground water as well as the surface water through rivers, lakes or reservoirs. Additionally irrigation needs for urban and recreational landscapes are consistently increased over the last years, as more people migrate to cities. Moreover, commercial and housing development expanded very rapidly up to 2010 while the tourist industry is under constant rise. Turfgrass (most varieties are notorious for their great water needs) remains the most common groundcover plant for all these cases.

Common sources of water for urban irrigation vary from shallow wells to water utilities. Some small amounts of treated municipal wastewaters are also used for irrigation purposes (irrigation of hotel green zones, municipal landscapes).

According to the literature findings (Karamanos et al., 2005), surface irrigation methods cover about 7% of the irrigated area while sprinkler and drip irrigation covered 49% and 44% respectively.

In Italy, the total area of arable land and permanent crops is between 9 and 9.5 Mha (FAO-Aquastat, 2015b). One third (2.7 Mha) of the total agricultural area is irrigated (Bartolini et al., 2010; Lupia, 2013). The irrigated area is very heterogeneous between the regions, ranging from 6% (Toscana) to 56% (Lombardia). Agriculture uses almost 67% of the total amount of the available water (Massarutto, 2013). The most common irrigated crops are grain maize, rotational forages, vineyards, fruit and berry plantations (Lupia, 2013). The main water sources are surface and underground water. In 2003, 329,032 farms were irrigated from the Irrigation and Land Reclamation Consortia while 397,199 farms were irrigated by other ways like self-supply etc. (Lupia, 2013). The underground resources contribute at an average of 25% nationally and almost 50% in some regions (Massarutto, 2013).

The great majority (76%) of irrigated farms use only one type of irrigation system (Massarutto, 2013). In 2007 the most used irrigation method was the sprinkler one covering about 37% of the total irrigated area of Italy, while surface irrigation (borders, furrows) ranged at the second place covering about 31% of that area and micro-irrigation in the third place covering 21.4% of the total irrigation area. However, in the southern regions of Italy like Puglia, where the climate is dry, micro-irrigation covered more than 50% of the irrigated area (Lupia, 2013; Massarutto, 2013).

Notes

Efficiency in various levels and factors that affect it Irrigation efficiency is a basic term used in irrigation science to characterize irrigation performance, to evaluate irrigation water use and to promote improved use of water resources, particularly those used in agriculture and landscaping management. In general, irrigation efficiency (IE) can be defined as a measure of the quantity of water that is beneficially used by plants.

Wu IE = 100× Eq. 1 Basic definition of irrigation efficiency (IE) Wd where Wu the volume of water that is actually used from the plants and Wd the volume of water that is transported to the irrigated area

Irrigation efficiency is measured in terms of: 1) irrigation system performance, 2) uniformity of the water application and 3) response of the crop to irrigation. All of these terms are interrelated and vary with scale and time (Howell, 2003):

• the spatial scale can vary from a single irrigation application device (a siphon tube, a gated pipe gate, a sprinkler, a micro-irrigation emitter) to an irrigation set (basin plot, a furrow set, a single sprinkler lateral, or a micro-irrigation lateral) to broader land scales (field, farm, an irrigation canal lateral, a whole irrigation district, a basin or watershed, a river system, or an aquifer).

• the timescale can vary from a single application (or irrigation event), a part of the crop season (field preparation, emergence to bloom or pollination, or reproduction to maturity), the irrigation season, to a crop season, or a year, partial year (i.e. summer, etc.), or a water year (typically from the beginning of spring snow melt through the end of irrigation diversion, or a rainy season), or a period of years (a drought or a “wet” cycle).

Irrigation efficiency affects the economics of irrigation, the amount of water needed to irrigate a specific land area, the spatial uniformity of the crop and its yield, the amount of water that might percolate beneath the crop root zone, the amount of water that can return to surface sources for downstream uses or to groundwater aquifers that might supply other water uses, and the amount of water lost to unrecoverable sources (salt sink, saline aquifer, ocean, or unsaturated vadose zone).

According to Bos (1983, 1990 and 2005) the irrigation efficiency of each network can be measured in each one of its levels: a) conveyance, b) distribution and c) field application. This is usually the case and thus during auditing an irrigation network is divided in several parts and each one is being evaluated separately according to its efficiency (conveyance efficiency, distribution efficiency, application efficiency, overall network efficiency).

Efficiency is affected by several factors. According to Irrigation New Zealand (2010) some of those are: a) climatic parameters (effective rainfalls, evapotranspiration etc.), b) soil and terrain characteristics (texture, depth, slope etc), c) design and materials of irrigation systems, d) central control of systems (entities organisation and applied management), e) maintenance of central systems, f) method and management of water application at end-user level and g) expertise level and training of managers and end-users.

A number of indicative examples follow (Irrigation New Zealand, 2010):

• The use of open canals having soil walls and bottom results a maximum efficiency of 40-50%, while modern closed pipe networks can achieve up to 80-90%.

• Old irrigation networks might be strongly ineffective because they are unable to be used under the modern irrigation practices or they are constructed in areas with erosion problems. For example, in cases where the gates are opened manually, their operation could be poor because of vandalisms and improper maintenance.

• Poor efficiencies could be caused by lack of water control during night or weekend irrigations. Some users are not used to irrigate during night, so the excess of delivered water is lost causing lack of water during the next day or at the next irrigated area. In some cases, such practices are the reason for building a secondary network of collecting this volume of irrigation water.

• Poor efficiencies could be caused by weaknesses regarding maintenance of irrigation networks. For example poor weed control can cause breakage at several parts of it. In other cases, because of degradation the width of canal increased and that caused changes in the delivered amount of water.

• The involvement of many organizations and users in the management of irrigation networks and the intersection of authorizations can cause misuse of the irrigation network system and inadequacies in delivery programs.

• Surface irrigation methods such as basin, borders and furrow, apply the water less efficiently (in many occasions more than 50%) than other methods.

Hamdy (2007) stressed the importance of increasing water use efficiency in the irrigation sector considering the growing water scarcity and the misuse of the available water resources in the Mediterranean region, by means of identifying the various components and improvements that can be made in irrigation practices.

Efficiency at basin and scheme level The management of water supply and application networks must be taken into consideration in order to improve the efficiency of irrigation systems. The process of managing an irrigation network includes network planning, implementation and evaluation. An effective design includes a number of steps to be made. First of all the surface water sources and the climatic conditions of the area must be registered. Secondly, the irrigated area and the crops witch are going to be irrigated must be recorded. Thirdly, the volume of transferred water and the required time must be calculated. This process usually relates to the whole catchment basin. Once the study of the catchment basin is completed, it must be decided whether one or more water supply networks are needed. Having completed the planning and construction of the network the operation process follows. The operation of the network is divided in simulation and full practical operation.

Fig. 16 Open irrigation canal at Arta plain constructed in 2013 (IRMA pilot audits, Arta, 2014)

For the evaluation of a water supply network, a number of indices are proposed. These must be scientifically acceptable and measurable, providing impartial information, being repeatable, being manageable and easy in implementation, referring to target values and being of low cost (Bos, 1997). Furthermore these indices should be related to the achievement of specific objectives such as identifying discrepancies between practice and desired-theoretical application, identifying where the operation needs to be improved and giving the kind of needed improvements. The indices are divided into operational and programming ones:

• Operating, which include the measurement of productivity and the ensuring of equity in water use between the users.

• Programming, which include measurements like adequacy, reliability, flexibility, sustainability and efficiency of the network.

The operating indices are defined as follow (Gorantiwar and Smout, 2005):

• Productivity is measured through other indicators such as: a) the achieved production compared to the desired one, b) the achieved economic benefit compared to the desired one and c) the irrigated area compared to the desired one.

• Equity, is defined as the distribution of input resources in the irrigation scheme (area and water) or the resulting output (crop production or net benefits) among users (farmers, outlet) in a fair manner which is prescribed in the objectives of the irrigation scheme in the form of social welfare. Equity refers to: a) the irrigated area compared to the total area covered by the network, b) the amount of applied water compared to the delivered amount through the network, c) the achieved yield compared to the expected and d) the achieved economic benefit compared to the expected.

The programming indices are defined as follows (Corantiwar and Smout, 2005):

• Adequacy is the ratio of supply due to irrigation and effective rainfall to the demand due to evapotranspiration and other needs. The adequacy of the network measured by either the maximum crop evapotranspiration or by the amount of applied water so that the soil moisture to reach the field capacity. In irrigation schedules where certain amount of water is applied during given interval, the second method of adequacy measures is better adapted. This indicator is important because it determines the type of irrigation (full or deficit) particularly if the network is not able to meet the irrigation needs of the covered area.

• Reliability is the ability of the water delivery system and the schedule to meet the scheduled demand of the crop. Likely, this is due to: a) the lower real water availability of the network compared to the calculated one, b) the unexpected changes in non-irrigation water demands, c) the miscalculation of water requirements, d) the loss of water from the network as a result of destructions or thieves and e) the inability of the managing authority to provide the needed water. In most cases it is desirable the network to provide more water than the calculated amount so that a high reliability to be met.

• Flexibility is the ability of the water delivery schedule of the allocation plan to recover from any changes caused in the schedule. During operation of irrigation systems various changes which have not been predicted is likely to be noticed. In these cases it should have been taken care for any change in the network’s operation to be assimilated without causing any impact on its efficiency. Usually networks designed for full or over irrigation conditions.

• Sustainability refers to leaching, cleaning the tubes from transported salts with the irrigation water and drainage. Systems where these parameters are not taken into account might lose their efficiency. Then extra amount of water is required, usually pumped from the underground aquifer, with adverse effects regarding irrigation cost and salinisation. Usually, sustainability measures are tested through simulation processes which are based on real data from each year of implementation.

• Efficiency is the last indicator used in the evaluation process. Most of times, when the designer of a network takes into account all the previously mentioned parameters, the network operates efficiently. Efficiency is an important indicator not only because it measures how efficiently the network operates but also because it is a helpful index for the authorities. Through efficiency they are able to notice if any problem in operation process occurs and then take the necessary measures to fix it.

The operation of the network may reveal deviations between practice and theory. Those deviations might exist due to: a) the spatial and temporal variability of some data used in the planning stage, b) the inaccurate description and calculation of some physical parameters and c) the possible divergences between theory and practice of certain interventions. van Halsema and Linden (2012), argued that water management decisions are made easier understandable by using Irrigation Efficiency and Water Productivity at the irrigation scheme and catchment level, respectively. They also proposed that their use can identify context specific

30 opportunities and potentials for increased water use efficiency and productivity as well as the potential trade-offs in water re-allocations between diverse water users and uses.

Efficiency at end-user level Except technical inspection, the typical information that is retrieved by measurements during an audit at end-user level is linked to distribution uniformity (how evenly) and precipitation rate (how intensively) water is applied in the various zones of the system. Regarding uniformity, the basic concept is that all irrigated areas within an irrigated field must receive the same amount of water. Areas of the field that are under-irrigated or over-irrigated will be under-irrigated or over-irrigated for all applications, multiplying the error (Kelley, 2004). Regarding precipitation rate -which is mainly an issue for sprinkler systems- it has to be much less than the infiltration rate of the soil in order that a reasonable duration of irrigation events would be allowed and the danger of surface run-off would be limited.

Table 1 provides generic values of end-users efficiencies. A number of relevant tables can be found in the literature (i.e. Howell, 2003). In some cases, these values are very optimistic (i.e. Greek State Gov. Gaz. (1989) states that the efficiency of surface, sprinkler and drip systems are 75%, 85% and 90% respectively).

Table 1 Expected application efficiency for agricultural applications (Brouwer and Prins, 1989) Irrigation methods Maximum field application efficiency Surface irrigation (border, furrow, basin) 60% Sprinkler irrigation (any type) 75% Drip irrigation (surface or underground*) 90% * this could be more than 95%

Problems arising from poor irrigation scheduling are often much more noticeable because they occur on a larger scale over a short period of time. Problems arising from poor irrigation uniformity occur at diverse locations in the field and often gradually appear over the growing season. Any type of irrigation system can be designed to provide good irrigation uniformity, but it is management’s responsibility to sustain the irrigation uniformity over the life of the irrigation system through proper maintenance.

Fig. 17 Installation fault, the hydrocyclone cannot operate, sand is passing in the system and the sprinkler nozzles require frequent replacement (photo from IRMA pilot audits, 2014)

Among the tools that can contribute to the improvement of the efficiency in irrigation systems is the irrigation audit. In the framework of an audit, recommendations are made based on visual inspections, catch can collections, soil observations, water pressure tests and discussions with site staff. Inferences and guidelines provided are based on industry best practices and manufacturers’ specifications. Deliverables from an irrigation audit include increased uniformity, decreased water window, water savings, healthier plant material and corresponding cost reductions from all of these improvements (Fig. 12, Fig. 13 and Fig. 14).

The ground for standardization of irrigation auditing was prepared from the 1940's. Christiansen proposed his well-known coefficient of uniformity in 1942, Criddle et. al. (1956) concentrated the methods of evaluating irrigation systems in a handbook while Merriam and Keller 1978 published a guide for farms' irrigation systems evaluation. Irrigation Association (2007a) has published a very practical and widely used, guide regarding audits of irrigations systems for landscaping projects while in 2010 Irrigation New Zealand published a very well structured code of practice regarding end-user irrigation systems evaluation.

Meanwhile researchers continued to evaluate the auditing methods and investigate the connection between application uniformity and qualitative and quantitative indices of the plantations. Smajstrla et al. (1990), presented procedures to separately evaluate the effects of pressure variations in the pipe network (hydraulic uniformity) and variations due to emitter characteristics (emitter

32 performance variation) on uniformity of water application. The knowledge of both of these factors, can help an irrigation system manager identify the causes of low application uniformities and the corrections that may be required to improve the uniformity of water application. These procedures should be used on newly installed micro-irrigation systems to verify that they were properly designed and installed, and to provide a reference for future evaluations. Also, evaluations should be done each year to determine the effects of emitter plugging or changes in other components on system performance. More frequent evaluations may be required to diagnose and treat emitter plugging problems. Goodwin and Salem (1990), proposed a procedure for irrigation sprinkler testing in which collecting cans are ‘optimally’ spaced in contrast to the general practice of ‘even’ spacing and showed that overall errors in data plotting are always less for optimal compared to even spacing for recordings over equal time intervals. Furthermore, they suggested a procedure for computing and applying optimal spacing as well as an outline of a cost-benefit analysis.

Fig. 18 Great water losses - very poor efficiency of a municipal irrigation system (photo from IRMA pilot audits, 2014)

Mantovani et al. (1995) and Li (1998) modeled the effects of uniformity of irrigation systems on crop yield. Choate (1994) and Puhalla et al. (1999) presented a number helpful references and relevant websites from universities, regarding the effective irrigation of sports fields. King et al. (2000) studied the irrigation uniformity of various agricultural irrigation systems like: center pivot and linear-move systems; wheel line and hand line systems; micro-irrigation systems etc. They concluded that the irrigation uniformity is an important consideration when striving to increase production efficiency in irrigated agriculture. Irrigation uniformity often receives little attention compared to irrigation

33 scheduling, yet it is just as important. ASAE (2003b) published a standard for field evaluation of micro irrigation systems. Its purpose is to establish minimum recommendations for the design, installation and performance of micro-irrigation systems: including trickle, drip, subsurface, bubbler and spray irrigation systems. It encourages sound system design and operation and enhances communication among involved personnel. It contains provisions affecting the adequacy and uniformity of water application, filtration requirements, water treatment, and water amendments. Weynand (2004) evaluated the uniformity of water application along drip laterals. This goal was reached, by evaluating the outcomes of a lab experiment in which subsurface drip laterals were placed on different slope and contour configurations, and evaluating drip laterals operated at three different subsurface drip dispersal systems under similar operation and maintenance procedures. Savard (2007), a specialist in irrigation audits for sports fields, noted that sports field irrigation management is site specific and the amount of water that a field needs is dependent upon a complex set of variables. These variables include turf species, soil and environmental conditions, amount of water it receives, and how the turf is managed. He stated that an irrigation audit is a tool used to integrate all of these variables into an irrigation plan that is effective and efficient. Luke and Bean (2007) wrote an irrigation management field guide which became the Irrigation Audit Manual of Albuquerque City in New Mexico, U.S.A.

Missing

Broken

Fig. 19 Various maintenance problems (photo from IRMA audits, 2014)

Fig. 20 Irrigation while raining. In areas with rains during the irrigation period, an auditor could recommend the installation of a rain sensor which could save a lot of water (Peta, Arta, 2015)

Le Grusse et al. (2009) proposed an approach to simultaneously take into account the technical, agricultural, economic and environmental objectives at the farm level, considered to be a relevant decision unit. Such indicators enable pertinent comparisons of different water management strategies in private, public and mixed systems while allowing for the performance of irrigated systems to be compared in terms of both effectiveness and efficiency. Raquel et al. (2011), presented a case study for irrigation performance in private urban landscape which represents an increasing share of total water use in semiarid areas. In this work, 102 households located in the Montecanal neighborhood (Zaragoza, Spain) were analyzed. A method based on reference evapotranspiration was used to estimate net landscape irrigation requirements. Overirrigation was common during the three years of study, with the average irrigation water application (IWA) being much higher than the Net Irrigation Requirements (1,359 and 555mm, respectively). Only 34% of the households showed adequate irrigation, while 6% of the households under irrigated their landscape areas. In the rest of the households (60%), overirrigation was observed. Olmsted and Dukes (2014) found that the most frequent problems in irrigation systems of residential gardens are: turf and shrub / tree area irrigated in the same zone; mixed sprinkler/emitter sizes & unmatched application rates in the same zone; stream of water blocked by vegetation and operating time too frequent and/or too long.

Fiscal returns that are expected from audits For the question “What can we expect from an audit?”, Pedro (2011) provides a synopsized yet complete list:

• A reduction in water use and consequently financial savings

• A more consistent distribution of water

• A smaller amount of water wasted below the root zone

• Less need for fertilizers and chemicals

• Less runoff

Wilson (2009), criticized irrigation audits for landscape setups. He stated that audit program’s primary ineffectiveness is tied to their real world application and results, not the math or science behind them. The concepts behind auditing make sense and are based upon qualified research by respected universities. The ultimate question is: Does an audit save more money than it costs? In other words when the time, effort, money and other resources involved in auditing are evaluated, is there a return on investment? Wilson (2009) concluded that this is not the case, mainly because few people actually follow through with all of the steps of an audit. The importance of this work stems from the fact that if we can give a positive answer to all the questions and solve the problems that are pointed out, then the effectiveness of the irrigation audit will be absolutely sure.

At the other hand IA (2007a) presented two case studies in which the average water savings after audits was about 500mm per year and the relevant value of saved water raised up to 850€ ha-1. With the audit cost at 100€ ha-1, the net savings where about 750€ ha-1.

Notes

Relevant legislation, standards, guidelines etc. A thorough search in ISO3, CEN4, NSSN5, UNI6 and ELOT7 revealed that while a great number of national and international standards regarding evaluation of irrigation and drainage system components and design of relevant system exist, only few active standards are relevant to field evaluation - audit of irrigation and drainage systems. Among them the following were distinguished:

• FAO Irrigation & Drainage paper 45 (Walker, 1989).

• USDA (1997) Engineering Handbook Part 652 - Irrigation Guide.

• ASAE EP458 (2003). Field evaluation of microirrigation systems (ASAE, 2003b).

• Irrigation New Zealand, Sustainable Farming Fund and Page Bloomer Associates Ltd, 2010. Irrigation Evaluation Code of Practice. Sustainable Farming Fund Project 02-051. This guide includes procedures for auditing of every kind of agricultural irrigation system

• Greek standards (ELOT, 2009) include a set of guidelines regarding the receipt of irrigation and drainage systems for public landscaping projects.

• ASABE/ICC 802-2014 (ASABE, 2014) Landscape Irrigation Sprinkler and Emitter Standard. This very recent standard is the first ANSI effort to establish uniform testing procedures for key landscape and irrigation systems components (sprinklers, bubblers, drip emitters and microsprays). It provides minimum design and performance requirements, and specifies uniform test methods for product performance. It also sets definitions and product classifications for commonly used sprinklers and emitters.

Irrigation Association (2007a) has published a very practical and widely used, guide regarding audits of irrigations systems for landscaping projects. IA states that in the framework of its irrigation audits, guidelines of the American Society of Agricultural and Biological Engineers (ASABE) standards are incorporated where possible. From 2002, IA also runs a very interesting initiative called Smart Water Application Technologies (SWAT) as a collaboration of water purveyors and the irrigation industry in USA (IA, 2014).

In 2006, the US Environmental Protection Agency (EPA) created a US national program called the WaterSense program to promote water efficiency similar to Energy Star for energy efficiency. In 2012, EPA's WaterSense labeling program began listing weather-based irrigation controllers (EPA, 2014). WaterSense criteria are based on the SWAT testing protocol but include modified requirements for minimum runtimes, missing weather station data, rainfall requirements and calculating the water balance (IA, 2013).

3 http://www.iso.org/iso/search.htm?qt=irrigation&sort_by=rel&type=simple&published=on&active_tab=s tandards 4 http://standards.cen.eu/dyn/www/f?p=204:105:0::::: 5 http://www.nssn.org/search/IntelSearch.aspx 6 http://www.uni.com/ 7 http://www.elot.gr

EIA (European Irrigation Association, 2014) refers in its training sessions overview that adopts internationally accepted methodologies for conducting irrigation audits.

Also at U.S.A. a multitude of States (e.g New Mexico, Texas, Albuquerque, Florida, California) and University Agricultural Extension Services have introduced such irrigation auditing guidelines.

UN, Food Agriculture Organisation (FAO)8 has published numerous guides, leaflets and tools regarding irrigation and drainage systems design, construction and management. A number of them concern the scheme level (Doughery et al., 1995; Snellen, 1996; SIMIS, 2001; Malano and Burton, 2001; Renault et al., 2007).

Of course the legislative framework that exists in each country should be followed during the design and management of irrigation systems and the consistency to it should also be checked during an audit. For example in Greece the following guides must be followed:

• Ordinance D24714/20-10-1969 for the determination of minimum and maximum velocity of water in closed pipes (YPEXODE, 1969)

• Determination of minimum and maximum limits of the necessary quantities for the sustainable use of water for irrigation (GMA, 1989)

• Modernisation of the methodology used for the calculation of plants water needs in the framework of relevant studies and adaptation to Greek conditions (GMA, 1992)

• Common Ministerial Decisions 16190/1335/1997 and 19652/1906/1999 (GG Β΄ 519 and GG B' 1575 respectively) regarding the protection of waters from nitrogen.

• Decision 85167/820, Code of Good Agricultural Practice, Section C (GG Β' 477, 6/4/2000)

• Decisions 145116 and 191002 for the use of reclaimed water (GG Β 354 8/3/2011 and GG Β' 2220 9/9/2013)

• Common Ministerial Decisions 43504/2005, 150559/2011 and 146896/2014 (GG B΄ 2878/27- 10-2014, GG 1784 Β' and GG 1440 Β' respectively) for the authorisation of using water resources.

• ELOT, 2009. 440 Greek Technical Standards (irrigation standards) (GG Β' 2221/2012)

• Determination of standards for gulf fields (GMT, 2014)

8 http://www.fao.org/nr/water/

Relevant books, software, training sessions and certification exams IA (Irrigation Association) offers a number of relevant stuff, namely9:

• Training sessions

o Golf Irrigation Auditor (Class). This 1-1/2 day session covers field tests and calculating accurate watering schedules using plant water use, soils and local weather data. It is recommended for the certified golf irrigation auditor exam.

o Landscape Irrigation Auditor (Class). This 2 day session covers field tests and calculating accurate watering schedules based on plant water use, soils and local weather data. It is recommended for the certified landscape irrigation auditor and certified irrigation contractor exams.

o Auditing of Landscape Drip Irrigation Systems (Seminar). Training about the practical things that can be measured and verified when auditing drip irrigation components in the field including ways to calculate an application rate to make better irrigation schedules.

o Auditing Ag Drip/Micro-irrigation Systems (Seminar). Provides info regarding how to evaluate how well the emissions devices are performing and the implications on irrigation scheduling and optimizing yield. Included in the discussion are problems found in microirrigation systems and their possible remedies.

o Auditing Center Pivot Systems for Nozzle Performance (Seminar). This seminar presents how to conduct an audit and to measure the performance of the nozzles. With this information, better decisions can be made about what repairs might be needed or how to better manage water resources knowing how the nozzles are applying the water.

• Books, guides, worksheets and software

o Irrigation audit guidelines

o Landscape and Golf audit worksheets

o Auditing and scheduling calculator

• Certifications

o Certified Landscape Irrigation Auditor

o Certified Landscape Irrigation Auditor - Drip

o Certified Golf Irrigation Auditor

9 http://www.irrigation.org/Certification/Certification_Splash.aspx

An indicative cost is between 250 and 500 US$ for training sessions and 30-50 US$ for seminars. Exams for Certification cost between 300 and 600 US$.

The EIA (European Irrigation Association)10 has set as goal to organise a relevant to the IA training and certification framework and by now provides a Certified Landscape Irrigation Auditor (CLIA) program. The cost to attend this course is about 400€.

Rainbird has organised the Rainbird Academy which also offers auditing training sessions11. An indicative presentation (Petro, 2011) is available online.

The sessions of IA and Rainbird are accredited with CEU (Continue Education Units).

Notes

10 http://irrigationeurope.eu/page/training-and-certification 11 http://www.rainbirdservices.com/index.htm

Auditors and providers of irrigation auditing services A number of private companies (mainly in U.S.A.) provide irrigation audit services. In Florida, a fleet of (MILs) provide auditing services to analyze irrigation systems and educate property owners on how to improve water use and promote conservation. Originally developed for agricultural purposes, now Urban Mobile Irrigation Labs (UMILs) perform the same service for residential clients (Olmsted and Dukes, 2014).

Fig. 21 Mobile Irrigation Laboratory and relevant training (UF/IFAS Extension, 2014) What is an irrigation auditor? According to Pedro (2011) an auditor should have knowledge of irrigation products and practices be able to effectively create an irrigation schedule. An auditors job is not to manage water, design systems, or even install them but is to compile data that is then used by designers, installers and managers.

Notes

Audits in the framework of IRMA project The IRMA project regards the regions of Puglia in Italy and Western Greece and Epirus in Greece (Fig. 22). The climate in Puglia and the western coast of Greece is of submediterranean to xerothermomediterranean type.

Fig. 22 Region of Apoulia (Italy) and Region of Epirus and Western Greece (Greece) (source: Google Earth)

Fig. 23 Audits in the framework of IRMA project at the Region of Epirus / Greece (photos from IRMA audits, 2014)

According to the project proposal an audit procedure would be developed, relevant equipment would be bought and 100 audits would be conducted in each country. The audits would concern mainly end-user systems (agricultural and landscaping), but also a limited number of higher level.

The procedure is described in the present guide, the equipment was acquired, a set of audits was used to evaluate the procedure and complete the guide and the total planned number of audits was performed. All the persons in charge for the audited systems, received the relevant evaluation results sheet.

Notes

A bit of theoretical background

Soil, soil water and roots Soil texture describes the size and shape of individual soil particles such as sand, silt, or clay. Soil texture class describes the relative amounts of sand, silt, or clay in that particular soil. Sandy loam, loamy clay, silty clay loam, etc. are examples of soil classes (Fig. 24). Soil texture has a major influence on the amount of water stored in a soil. It also has a major influence on soil infiltration rate (the rate at which water enters the soil profile) and the permeability of a soil (the rate at which water moves through the soil). Soil structure is the arrangement of soil particles. Soil particle refers to any unit that is part of the soil makeup including primary elements (sand, silt, or clay) or secondary aggregated particles.

Fig. 24 The soil texture triangle showing the 12 major textural classes (USDA, 2014)

Active root zone (RZ) or effective rooting depth) is the soil depth from which a crop extracts most of its water needs. The active root zone is expressed in length units, typically mm, cm or m.

According to FAO paper 45 (Walker, 1989) important soil characteristics in irrigated agriculture include the water-holding or storage capacity of the soil; the permeability of the soil to the flow of water and air; the physical features of the soil like the organic matter content, depth, texture and structure; and the soil's chemical properties such as the concentration of soluble salts, nutrients and trace elements.

Field capacity (FC) is the water content of the soil that is reached after a rain or adequate irrigation event and when water has been removed by the downward forces of gravity. Field capacity differs from saturation. When the soil is saturated, all the pores are filled with water. When the soil is at field capacity, the maximum water quantity can be kept in the root zone; plants do not need to consume a lot of energy in order to take up water from the soil and the spaces between the soil particles, the pores, contain both air and water. At the other end there is the permanent wilting point (PWP). This state is reached when the water content is too low for the plant to remove water from the soil. The soil structure and texture determine both its FC and PWP levels. Total available water for plants (TAW or just AW) is the water content difference between FC and PWP (Fig. 25).

Fig. 25 Basic soil water parameters

For hydroponic substrates, the container capacity (CC, analogous to field capacity) is the moisture for water suction of 10 cm (1 kPa), the easily available water (EAW) is the moisture difference between 10 and 50 cm of water suction (1 and 5 kPa) and the water buffering capacity is the moisture difference between 50 and 100 cm of water suction (5 and 10 kPa). In order to have a reasonable schedule for hydroponic systems, the percentage of EAW which will be consumed before the initiation of a new irrigation event is defined by the acceptable level of hydraulic conductivity (Fig. 20).

Fig. 26 Water retention and hydraulic conductivity curves for hydroponic substrates (Raviv et al. 2002) Plant water needs Although the water requirements of each crop or landscaping layout can vary widely, the physiology of water use by the plant is similar in all cases. Plants use water to achieve three major purposes:

• As a mean to transport dissolved chemicals and minerals (fertilizers) from the plant roots to the rest of the plant.

• As a mean to control physical shape and direction of growth of the plant (water pressure in plant cells provides structure).

• As a mean to control leaf temperature by evaporation from leave’ stomata (by far the major use in warm climates).

When adequate moisture is available to the plant, a continuous flow of water exists from the roots up to the leaves. If inadequate moisture is present in the soil or if the rate of evaporation from the leaves exceeds the rate at which water can be moved upwards by the plant, then water related stress ensues. At the other hand too much water in the root zone for long periods can also be damaging to plants due to a reduction in oxygen around the roots. This can occur when irrigation is performed too frequently in an amount too great for the plant to remove and use. The development of a shallow root zone can be another limited factor of frequent irrigation.

The water needs of the plants no matter if they are cultivated species or ornamental plants and turfgrass are being calculated in relation to reference evapotranspiration (ETo). FAO paper 56 (Allen et al., 1998) is the word wide accepted standard for estimation of open field cultivations’ water needs. It includes two models for ETo calculation, namely: the Penman – Monteith which is more demanding regarding inputs and the Hargreaves & Samani one. ETo must multiplied by crop and environment related factors in order to provide an estimation of the plants water needs (Fig. 27, Allen et al. FAO p56-1998, 1998; UCCE and CDWR, 2000).

Fig. 27 Basic model of water needs calculation (FAO p56, Allen et al, 1998)

FAO has developed a special software in order to facilitate the application of paper’s 56 procedures (Fig. 28). The water needs are typically given in units of depth (volume per unit area) or simply the volume for the area being evaluated.

Fig. 28 Screenshot from CROPWAT, the FAO software which applies FAO paper 56 procedures

Irrigation system design and construction Irrigation systems follow adopt the basic methods that have already mentioned (surface, sprinkler and micro irrigation). In general all systems is composed by (Irricad, 2014):

• a number of zones which include zone (or sub main) pipes and laterals (pipes on which the outlets are connected), each zone runs a specific irrigation schedule

• a mainline which connects the zones to the water supply/ies

• control valves through which zones are connected to the mainline system12.

12 Typically an irrigation zone means an area where all the parameters affecting the schedule are similar. In cases where water flow is not sufficient to irrigate the entire zone at the same time, it is divided in stations where the same schedule is applied.

Fig. 29 A typical micro-irrigation system

A number of standards must be followed when an irrigation system is designed and constructed. This obligation is related to the legislation of each country (USDA, 1997; ELOT, 2009 etc.). Also a number of relevant guides are available from widely approved organisations like FAO, IA etc.

Basic concepts include the adoption of soil and terrain characteristics, the specific needs of the plants and their layout, the water source characteristics, the water flow limits inside the pipes (typically it is suggested to be between 0.5 and 2 m s-1), the pressure across the system, the protection of materials and components, the safety of users and constructors.

Fig. 30 Solid set sprinkler system layout (USDA, 1997)

Fig. 31 A springer irrigation system for a football field (Rainbird, 2014)

Two important characteristics of the system operations are its design capacity and its precipitation rate.

Irrigation systems shall have a design capacity adequate to satisfy the peak irrigation water requirement as described before of each and all crops to be irrigated within the design area. The capacity shall include an allowance for water losses (evaporation, runoff, deep percolation) that may occur during application periods. The system shall have the capacity to apply a desired amount of water to the design area in a specified net operation period. The system should have a minimum design capacity sufficient to deliver the peak daily irrigation water requirements in about 90% of the time available or not more than 22 h of operation per day.

PR = Q / A Eq. 2 Precipitation Rate where PR is the precipitation rate (mm min-1), Q is the system flow (L min-1) and A is the irrigated area (m-2)

Precipitation Rate (PR, Eq. 2) is the rate at which irrigation water is applied per unit of area. PR is usually measured in mm of water per min or hour (mm min-1 or mm h-1). It is calculated as an average within a given area. PR is a critical factor in design, because for example sprinkler systems can easily apply water at rates greater than the soil's intake rate.

An ongoing maintenance program is necessary to ensure peak system performance. Heads must be properly adjusted, pressures corrected, and equipment replacements must be consistent with the original design specifications. These items have a strong influence on distribution uniformity. By maintaining high distribution uniformity, it is possible to keep water use to a minimum.

Irrigation system management / scheduling Irrigation scheduling includes the determination of both frequency and duration of irrigation events in order to maintain soil moisture within desirable limits (Fig. 32). The goal of irrigation is to restore the water that has been "consumed" through evapotranspiration to a level close to field capacity. In some special cases (i.e. saline soil conditions) more water is provided in order to create an optimum root environment.

Maximum or Management Allowed Depletion (MAD) is the maximum amount of plant available water that the irrigation manager allows to be removed from the soil before irrigation occurs. Increased surface evaporation of water and usually higher rates of transpiration are associated with high frequency irrigation. It is best to irrigate only when the root zone has reached MAD. For most landscape purposes, 50% MAD represents a reasonable overall value. For sensitive plants, shallow root zones (where little reserve water is available), or heavy, compacted soils, a smaller depletion of the plant available water should be considered (MAD of 30-50%). For stress-tolerant plants, deep root zones or light soils, a larger depletion can be used (MAD of 50-70%). That classification is used in crop irrigation. Analytical tables are presented in Allen et al., (FAO p56-1998). A 50% MAD allows a buffer in case of unexpected "down time" of the system. Using high values of MAD with coarse textured soils and/or a shallow root zone can be very dangerous. This combination may not leave much room for scheduling error.

Fig. 32 Basic concepts of irrigation scheduling

A well-managed irrigation schedule incorporates the following scheduling factors:

• The proper amount of water (considering weather and plants)

• The proper frequency of irrigation (based on the soil's ability to store water and the intake rate of the soil).

• The performance characteristics of the irrigation system (i.e. how quickly and evenly water is applied to the landscape).

• The features of the irrigation controller and the characteristics of the site that determine appropriate program start times and maximum station run times without runoff.

Typically a base -theoretical- schedule is set and then is adjusted to take account of the actual conditions. The base schedule is based on soil, plant, climatic (averaged weather data) and irrigation system parameters.

Base schedules must be adjusted to match changes in the weather. These changes may occur from week-to-week and most certainly will occur from season-to-season. Tracking water use and comparing this to the calculated amount is a method of ensuring that water use is appropriate for the current conditions and plant material.

For the case of cultivations on soil and for landscaping projects, irrigation events may repeated after some days, weeks or months (Fig. 27). At the other hand for cultivations and landscapes that grow on substrates (for example hydroponics and roof gardens respectively) a number or irrigation events may be needed every day (Fig. 34).

The main ways to apply an irrigation schedule are the following:

• Manual empirical management: Irrigation management based on local traditional schedules and empirical decisions based on farmers feeling of the cultivation water status (visible signs of plant’s wilting) soil moisture estimation.

• Manual management based on ET or relevant climatic and soil factors data.

• Automated irrigation management where relevant decisions are typically based on:

o Predetermined timing (based on substrate, crop and system characteristics)

o Direct sensor measurements of ambient and/or soil parameters (in combination or not with predetermined timing)

o Direct sensor measurements of both soil and ambient environment parameters in combination with crop models)

Irrigation automation can improve water management, but it should be used in conjunction with good human management. In automated irrigation, a controller operates solenoid-equipped valves at specified times and durations. While the controller may remember to turn the irrigation system on and off, it takes human management to determine whether there is too much runoff or few or no plants in an irrigation zone being irrigated. Automation is a tool to help the operator improve water management, not a substitute for human judgment (IA, 2007a).

Table 2 Guidelines for irrigation management (IA, 2007a and b) Procedure Description

Implement Base Ensure that the implemented, typically with a controller-by-controller Schedule process Schedule Adjustment Once in operation, run times of individual stations may need to be Fine Tuning adjusted due to differences in microclimate, precipitation rate and uniformity. Trim Back It is possible to reduce irrigation amounts by periodically cutting back" Weather Changes until stress is seen. Unacceptable controller programs be quickly modified to reflect weather changes

System Maintenance Proper irrigation maintenance practices will keep the irrigation system operating as efficiently as possible. Inspect the site and repair any problems. An inspection should be made on a routine basis. Track Water Use Tracking water use provides useful feedback to the irrigation manager about actual performance vs. budget

Fig. 33 Weekly soil water content fluctuation because of irrigation

Fig. 34 Daily variation of water content (WC) and electric conductivity (EC) at the substrate of a hydroponic cultivation (Lee, 2010) Application efficiency Application efficiency is the amount of available water, divided by the average amount of water applied during an irrigation event. The amount of available water depends on how long the system is operated as well as the distribution uniformity (Fig. 35). Efficiency is affected by both site management and equipment at the site. Uniformity is primarily related to the design and mechanical performance of the irrigation system.

GOOD UNIFORMITY (IT CANT BE PERFECT) - - - - Depth of Water

POOR UNIFORMITY - - - - Depth of Water

Fig. 35 Irrigation uniformity and effects on plant's growth

To estimate the net amount of water that is stored in the root zone after irrigation, losses such as evaporation, wind drift, deep percolation, and low head drainage need to be determined. With a

54 large number of irrigations occurring during a year, it is difficult to determine overall irrigation efficiency for an entire irrigation season.

Distribution uniformity Although related, the concepts of efficiency and uniformity are different. For example, a system can have high uniformity, but have low efficiency because of excessive run times. Ideally, both high uniformity (giving good appearance) and high efficiency (providing minimum water use) should be achieved.

Distribution Uniformity of outlets discharge or pressure cannot be considered identical to efficiency, but it provides a sense of the IE level under the condition that adequate management is applied (Burt, 1997; Irrigation Association, 2007b).

Many irrigation managers attempt to overcome poor uniformity by applying more than the necessary amount of water, so that an adequate amount is received at the driest location. This practice is one of the leading causes of deep percolation. Some of the problems associated with this practice are:

• The amount of water available may be limited by regulation.

• The high cost of water.

• There is the chance of damaging plants in areas with wet spots due to excessive water in the root zone.

Good distribution uniformity minimizes the amount of extra water needed to provide the driest location in the system with an adequate supply.

After infiltration, a redistribution of water is expected in the soil / substrate. The layout of this is related to the characteristics of the soil / substrate. This will lead to the actual uniformity, which can be evaluated only with soil moisture sensors (Fig. 36).

Fig. 36 Soil moisture distribution in a rockwool slab after an irrigation event (Bougoul and Boulard, 2006).

Audits of irrigation and drainage components at factory

Outlets are evaluated regarding their application rate and uniformity at the factory before they are released to the market (Fig. 31). For sprinklers, a diagram is produced using the evaluation data (Fig.

38), while for dripper the coefficients that dictate the flow - pressure equation are determined (Eq. 3 and Fig. 39).

Fig. 37 Factory test of Hunter MPR (Hunter Industries)

Fig. 38 Relationship between precipitation rate and distance (left) and relationship between operating pressure, distance and profile (right) for various sprinklers

x q = K d × P Eq. 3 Relationship between emitter operating pressure and flow rate where q is the emitter flow rate (L h-1), Kd is the emitter discharge coefficient, P is the operating pressure (bar) and x is the emitter discharge exponent. For pressure compensating emitters x=0.

Fig. 39 Emitter pressure - discharge relation

Evaluation of uniformity during the design process

Computer modeling is a way to see the results of an irrigation design before you actually install the system. The computer can "model" a sprinkler and spacing design by using data from a single leg test or from a full grid catchment pattern of a single sprinkler (Fig. 40).

Fig. 40 A densogram with indications of the wettest (green square) and the driest (red square) areas (screenshot from SPACEPROTM)

Evaluation of precipitation rate and uniformity after installation of the system

Reality may differ from the design values and thus measurements of PR and uniformity assist the manager to adjust the schedule that will be actually applied and in many cases detect problems regarding the system operation.

The term catch-can is generally used for the containers that are used to collect water from outlets during an audit test. In general any kind of container can be used as a catch – can (Fig. 41) but there are also containers that have been fabricated for this specific scope (Fig. 42).

Fig. 41 Irrigation auditing catch-cans

Fig. 42 Alternative containers used as catch-cans

Distribution uniformity indices

Modified Interquartile Ratio (MIR)

Modified Interquartile Ratio (MIR, Gorantiwar and Smout, 2005) is used in scheme level evaluations and is defined as “the average allocation ratio of the poorest quarter divided by the average allocation ratio of the best quarter”. Values of MIR vary between 0 (total inequity) and 1 (perfect equity).

Christiansen’s Coefficient Uniformity (CU)

Although CU (Christiansen, 1944) is widely accepted for agricultural irrigation systems, its application to turf is limited due to its failure to distinguish between areas that are either too wet or too dry.

n ∑ Vi −V = − i=1 CU 1 n Eq. 4 Christiansen’s Coefficient Uniformity (CU) ∑Vi i=1 where CU is the Christiansen’s uniformity coefficient (%), Vi is the water volume collected by the i catch-can and Ṽ is the sample average

Lower half and Lower quarter Distribution Uniformity indices (DU)

The lower half and the lower quarter distribution uniformity indices are among the most commonly used in uniformity audits for landscaping sprinkler systems.

AVGq DU = ×100 q AVG

Eq. 5 Lower half and the lower quarter distribution uniformity AVGh DU h = ×100 index (DU) AVG

DU h = 0.386 + 0.614× DU q where DUq and DUh are the lower quarter and the lower half distribution uniformity respectively (%); AVGq and AVGh are the average of the lower 25% and 50% of the sample respectively and AVG is the average of total sample.

According to the Irrigation Association (2007a), the Lower Half Uniformity is proposed for application in domestic irrigation networks because the Lower Quarter Irrigation Distribution Uniformity overstates the effect of heterogeneity in green landscape areas. However, the most researchers use the DUq.

The DUq of a system with rotary sprinklers is typically higher than this of one with spray heads. The spray heads have closer spacing and a higher precipitation rate. Therefore, overirrigation may be

59 exacerbated in some areas, thus decreasing uniformity. The spray heads have the better uniformity when fixed quarter circle nozzles are used as opposed to adjustable arc nozzles (ASAE, 2002).

Table 3 Distribution Uniformity (DUq) and expected efficiency of the system (Beard and Kenna, 2008).

Type of outlet Distribution Uniformity (DUq) and expected efficiency of the system Perfect Very good Good Moderate Bad (difficult to, (can be (expected, can (can be (need but be achieved) be improved) improved) improveme achieved) nt)

85% 80% 75% 65% 55%

75% 70% 65% 60% 50%

70% 65% 55% 50% 40%

Scheduling Coefficient (SC)

The scheduling coefficient is a measurement of irrigation uniformity in an area that was developed for turfgrass irrigation. It is based on the critical turf area because in turfgrass irrigation it is common to irrigate any critical area until it is sufficiently watered. The SC indicates the amount of additional water needed to adequately irrigate the critical area. In the purest form, scheduling coefficient is based upon the absolute lowest precipitation rate versus the average precipitation rate. The critical area is typically defined as a percent of the total area (1%, 5% or 10%). SC's optimum value is 1.0 but the best sprinklers in the market produce a SC between 1.15 and 1.5 (Fig. 43). In practice SC is used for multiplying the system run time, i.e. if SC=1.2 and it has been calculated that the run time should be 30min then the actual run time should be 1.2x30=36min in order the areas that receive less water to get at least the expected amount of water.

PRaverage SC = Eq. 6 Scheduling coefficient (SC) PRminimum where PRaverage and PRminimum are the mean and the minimum precipitation rates that have been measured.

Based on the expected pressure the installation distance can be selected in order to achieve the best possible SC.

In some circumstances the use of the absolute minimum precipitation rate at the denominator of Eq. 6 can lead to very large SC. A solution is to –according to the judgment of the auditor- use an average minimum, for example the average PR of the lowest quarter.

Fig. 43 SC for a specific sprinkler model

The difference between SC and DU is the fact that SC uses a contiguous area (for example 1%, 5%, 10%, etc.) in defining the dry spot (critical) area to be used in establishing design and operational parameters. DU uses an arbitrary 25% or 50% of the lowest catch device measurements regardless of location. They may or may not define dry spots. A dry reading could be adjacent to a wet reading thereby modulating the dry spot effect.

Statistical Uniformity (Us)

This index is suggested by ASAE (2003b) for micro-irrigation systems. When the emitter flow rate variation increases the uniformity of water application decreases. In addition to flow variations due to pressure, variations between emitters of the same type also occur due to manufacturing variations in the tiny plastic components.

U s =100%×(1−Vqs ) Eq. 7 Statistical uniformity (Us) where Vqs is the statistical coefficient of variation of emitter discharge rates, equal to the ratio of the sample standard deviation divided by the mean. Vqs includes the effects of variability in emitter flow rate from all causes, including both water pressure distributions and emitter hydraulic properties, emitter plugging etc.

Table 4 Micro-irrigation system uniformity classifications based on emitter discharge rates (ASAE, 2003b) Classification Uniformity, Us (%)

Excellent Above 90%

Good 90%-80%

Fair 80%-70%

Poor 70%-60%

Unacceptable Below 60%

Design Emission Uniformity or Emission Uniformity (EU)

According to Irrigation Association (2007a), EU can be measured in both flow and pressure basis.

EU = (1−1.27 ⋅Cv / n) ⋅ (Qmin / Qmean ) Eq. 8 Emission uniformity (EU) x EU = (1−1.27⋅Cv / n)⋅(Pmin / Pmean ) where n for a point−source emitter on a perennial crop, the number of emitters per plant; for a line−source emitter on an annual or perennial row crop, either the lateral rooting diameter of the plants divided by the same unit length of lateral line used to calculate Cv or 1, which is greater; Cv is the coefficient of variation (provided by the manufacturer); Q and P are the flow rate and the pressure respectively (minimum and mean) while x is the emitter discharge exponent (expresses the sensitivity of the emitter to pressure alteration). Table 7 presents recommended ranges of EU values.

The manufacturer’s coefficient of variation (Cv) is a measure of the variability of discharge of a random sample of a given make, model and size of emitter, as produced by the manufacturer and before any field operation or aging has taken place.

Cv = S / x

1/ 2  n  ∑(xi − x) Eq. 9 Coefficient of variation (Cv) S =  i=1   n −1    where ẍ is the mean discharge of emitters in the sample; S is the standard deviation of the discharge of the emitters in the sample; xi is the discharge of an emitter and n is the number of emitters in the sample

A general guide for classifying Cv values is presented in Table 5.

Table 5 Recommended classification of manufacturer’s coefficient of variation (Cv) Emitter type Cv range Classification

Point-source 0.05 excellent 0.05 to 0.07 average 0.07 to 0.11 marginal 0.11 to 0.15 poor 0.15 unacceptable Line-source 0.10 good 0.10 to 0.20 average 0.20 marginal to unacceptable

Table 6 Recommended ranges of design emission uniformity (EU) Emitter type Spacing (m) Topography Slope, % EU range, %

Point source 0.4 uniform 2 90 to 95 Perennial crops steep or undulating 0.2 85 to 90

Point source 4 uniform 2 85 to 90 Perennial or semi-perennial 4 steep or undulating 0.2 80 to 85 crops Line source On all uniform 2 80 to 90 Annual or perennial crops On all steep or undulating 0.2 70 to 85

Accuracy of estimates

The estimates of uniformity and performance variations made using the methods presented in this publication are based on statistical samples of pressures and flow rates measured in the field. As with any statistical estimate, the results will not be completely accurate unless all emitters are sampled. Thus, it is necessary to consider confidence limits on the estimates made when only a few emitters are sampled. This is a method of estimating how accurate the measured result is, and whether it is necessary to make additional measurements to improve the accuracy.

Table 7 provides confidence limits on the uniformities or variabilities measured. From Table 7, the confidence limits are smaller when the uniformity is greater. For example, for 18 samples, the confidence limit is ±3.5% if the uniformity measured was 90%, while the confidence limit is ±16.2% if the uniformity measured was 60%. This means that the actual uniformity would be expected to be in the range of 86.5% to 93.5% (90% ± 3.5%) if the estimated value was 90%, while it could be expected to range as much as 43.8% to 76.2% (60% ± 16.2%) if the estimated value was 60%. The smaller

63 confidence limits occur at the higher uniformities because it is not likely that samples would be randomly selected that would indicate a high uniformity if the uniformity was actually low.

From Table 7, the confidence limits decrease as more samples are taken. This indicates that we are more confident in the results if more measurements are made. In fact, the confidence limits decrease by a factor of two when the number of samples is multiplied by four. If the uniformity estimates are low when only 18 samples are taken, then more samples must be taken in order to improve the confidence in the estimate. Thus, Table 7 can be used to determine the number of samples that must be taken in order to estimate the actual uniformity with the desired accuracy.

Table 7 Confidence limits (90% level) on statistical uniformity estimates (ASAE, 1996)

Uniformity Us (%) Number of samples Variability Vqs (%)

18 36 72 144

90% 3.5% 2.4% 1.7% 1.2% 10%

80% 7.3% 5.0% 3.4% 2.4% 20%

70% 11.5% 7.8% 5.4% 3.8% 30%

60% 16.2% 10.9% 7.6% 5.4% 40%

Design and operation parameters that influence uniformity

Sprinkler selection during the system design influences uniformity. Examples of selection options include: spray vs. single nozzle vs. multiple nozzle, sprinkler pressure and pressure variation, sprinkler spacing, and sprinkler location with respect to landscape features. Other factors affecting performance include wind, plant interference, and equipment damage. Installation and maintenance specifications must maintain the intent of the design to insure proper performance.

Sprinkler Distribution Profiles/Spacing: A design consideration affecting the performance of an irrigation system is the sprinkler water distribution profile. A single sprinkler head typically is not designed to distribute water evenly across a given area. As the distance from the sprinkler head increases, the water being delivered is spread over an increasingly larger area. Many sprinklers distribute about the same amount of water into each radius range. This results in less water being applied to the area farthest away from the sprinkler head. Sprinkler systems must be designed so that individual patterns overlap in order to provide a reasonable level of uniformity. If the spacing is not consistent, the uniformity will be adversely affected.

Irrigation Water Losses: Irrigation water may be lost through evaporation, wind drift, over spray out of the irrigation area, deep percolation or runoff. Evaporation losses are increased by high winds, high temperatures and low humidity, which is why early morning irrigation is normally efficient.

Wind condition is another important consideration because the wind can move water droplets away from their intended destination. Wind drift losses are highest when wind velocities are highest and

64 water droplet size smallest. In windy areas, special design strategies of low trajectory sprinklers and minimum operating pressure must be employed.

Overspray losses not caused by wind are usually the result of design compromises or lack of proper arc adjustment along hardscape edges. The typical values for water losses are shown in Table 8.

Table 8 Typical irrigation water losses Range

Wind and evaporation 1 - 20%

Edge control 1 - 15%

Pressure differences at the emitters throughout the system (or block or subunit) should be maintained in a range such that the desired design emission uniformity (EU) is obtained. Since the allowable pressure loss corresponding to the minimum emitter discharge rate will differ depending on the emitter characteristics, the allowable pressure variation should be stated in writing for the specific emitter type and Cv specified.

Incorrect scheduling can increase water losses in many ways. For example:

• Using multiple cycles without check -valves in sprinklers (low head drainage)

• Running too many stations at a time, resulting in low pressure and pattern distortion

• Irrigating every day, when not necessary, resulting in excessive evaporation and increased plant water uptake

• Running cycles for too long which results in runoff

• Running too many total minutes, resulting in deep percolation

• Improperly balanced run times produce system-wide non-uniformities

Notes

Auditing of irrigation systems

What is and what can we expect from an irrigation and drainage system audit An audit is an integrated evaluation of a system considering both infrastructure and management aspects. In the framework of an audit; observations, measurements, discussions, calculations and presentation of results are combined in order to contribute to the improvement of the system’s performance.

Fig. 44 A continuous improvement circle

An audit can provide information on the following:

1. Current operating efficiency and uniformity of the system

2. Faulty equipment and weaknesses in the system

The potential benefits of an audit are:

1. Water, energy and labor savings

2. Nutrient savings and reduced release of nutrients to the environment

3. Higher quality of agricultural cultivations and landscape

In order to achieve those expectations the following components are needed:

1. An well organized and team staffed with appropriate personnel (experts and technicians)

2. Well-designed procedures

3. Suitable field equipment and laboratory support

4. System managers that are willing to learn and improve their systems through audits

Audits at irrigation scheme level The present guide is not focused on scheme level audits and thus only very basic relevant information will be provided. In irrigation schemes, the organization that distributes the water is often of a public nature, while the group of farmers receiving the water is often again a private institution. This mix of public and private institutions who all have their different rules makes irrigation management especially difficult (Snellen / FAO 10, 1996). Except of that mixed mode, two other types exist, the public-managed schemes and the farmer-managed schemes. In public- managed schemes, a single government agency is responsible for water management and for agricultural management. As all decisions about cropping schedules and water deliveries are made by the same agency, there are fewer conflicts. The disadvantage is that any management mistakes will also lead to failure on a large scale. The position of farmers in a public-managed scheme is more similar to that of workers in a factory. In farmer-managed schemes, all decisions on irrigation and agricultural issues are made by farmers. The irrigation issues above the farm level, such as main system operation and maintenance are performed by farmers operating as a group. Irrigation and agricultural issues at the farm are decided by the individual farmer.

Managing an irrigation scheme often involves 2-3 different organizations: the scheme operators, who manage the water from the main intake structure to each of the outlets shared by a group of farmers; the farmers who share a common outlet and if the scheme operators depend, wholly or partially, on financing by the government, there is even a third party involved: the government.

Among the various approaches for scheme level evaluation MASSCOTE can be distinguished (Renault et al. / FAO Paper 63, 2012). MASSCOTE is a step-wise procedure for auditing performance of irrigation management, analyzing and evaluating the different elements of an irrigation system in order to develop a modernization plan. The modernization plan consists of physical, institutional, and managerial innovations to improve water delivery services to all users and cost effectiveness of operation and management. MASSCOTE is founded on a rigorous on site approach of the physical water infrastructure (canals and networks) and introduces service oriented management as a normal practice. A number of modules have been developed in this framework (i.e. MASSLIS (Lift Irrigation System), MASSMUS (Multiple Use of Water Services), MASSPOT (Pressurized irrigation systems), MASSFIELD (Rapid Audit of performance at Field level for different techniques) etc.).

End-user level (farm, municipal landscape, private landscapes of various sizes) The field of application of end-users audits includes agricultural cultivations irrigation systems (open field and under cover), public and private landscape irrigation systems / recreation (parks, campuses, institutions, parks, sports facilities (golf, football, tennis, etc.), tourist and recreational facilities, private gardens etc.).

The main objective of an audit is to measure the irrigation efficiency. According to bibliography during an effective irrigation the runoff and deep percolation are minimized. The auditing will be based on independent auditors as well as the self-management (user) approach. It is well known that problems might be observed during an irrigation process. Those problems must be noted through auditing and the right decisions must be informed to the user, in report form, so as the user to improve the irrigation efficiency.

High irrigation efficiency prerequisites a well-designed irrigation network as well as an optimum operation and maintenance policy. A poor-designed irrigation network is economically and environmentally inefficient as there might be water losses during the application or distribution from the main basin’s network. During the first three years of audit process each user has to be audited annually. After that period of time the auditing can be done periodically according to the specification of the area as well as the degree of the user’s compliance. Poor operation or maintenance could be followed by some kind of penalties.

The auditor should cooperate with the user during the auditing as well as possible. Good cooperation helps to gather as much information as possible in the shortest time. First of all, the Auditor has to analyze the aim of auditing procedure. It is often useful to be described the benefits of auditing to the user, to the subsequent users and to the environment. Moreover, the auditing requirements are being analyzed too and the necessary actions to improve the efficiency of irrigation system are proposed according to each audited field (user) specialty. The necessity of re-auditing of the field at regular intervals must be explained to the user so that the audit procedure to be embedded by the user. Furthermore the repeated assessment improves the experience of the user in optimal use of irrigation practices. Finally, the coordination among the users and the focused implementation of the Auditor’s proposals could help to avoid duplication of adverse effects of poor operation of irrigation and reduces delays in the irrigation program (Mulcock et al., 2009).

The audit covers two management sectors:

• The management of irrigation water to optimize water use efficiency and minimize runoff and deep percolation.

• The soil management as it affects the irrigation efficiency, directly. The hydraulic parameters of soil vary with the cultivation technique carried out and thereby determine to what extent irrigation process is efficient. The aim is the soil properties to be kept in optimal physiological and biological status.

The auditing of the irrigation management must fulfill five targets. These are (Mulcock et al., 2009):

• Compliance with those practices that optimize irrigation

• Confirmation that the user operates each irrigation system according to the requirements of the auditing process and optimal irrigation practice

• Confirmation of the user’s knowledge about the optimal maintenance principles of his irrigation systems and to what extent they are used in practice

• Maximization of irrigation efficiency and minimization of runoff and deep percolation

• Implementation of the optimal equipment maintenance practices.

The soil management includes three more targets. The soil must be cultivated such as the following targets to be fulfilled (Mulcock et al., 2009):

• The effects of wind and irrigation on soil erosion to be minimized

• The soil structure and biological activity to be optimized

• The risk of contamination of soil by over fertilisation to be minimized.

Notes

Organisation of an audit team (people and infrastructure)

Personnel An audit team should be consisted of trained irrigation and drainage experts who would be able to evaluate the operation of a wide variety of systems, through observations, measurements and discussions with the managers and the end-users (Putnam, 2010).

The team leader must be proficient in agriculture, agricultural economy, agro-meteorology, hydrology, hydraulics, irrigation and drainage with a minimum experience of 36 months in irrigation auditing. They have to supervise the team members so as to achieve optimal team goals and assess the reports as well as to provide training to personnel in water conservation project policies, procedures and techniques. Additionally, they have to organize and publish the general results of the evaluations each period through the use of mass media, seminars, lectures and educational workshops to the target groups (landowners, system managers and operators) and to produce technical reports and administrative records for any interested or involved agency. Furthermore, the team leader could gather planning information about the natural resources necessary for early and efficient resource management plan; analyze simple or complex irrigation systems which greatly vary in size, type, application and purpose.

Each team member must, at least, have basic knowledge in irrigation and drainage with a minimum experience of 12 months in relevant systems operation. They have to perform the site work, to feed the databases with the collected data, analyze and evaluate them and inform the team leader about each evaluation. Additionally, they have to be able to explain the outcomes of the audit to the systems’ managers and provide relevant technical assistance to them. Furthermore, they have to assist in the organization of educational workshops and presentations.

Field work consists of at least two people available, depending on the surface and the use of the he system under evaluation.

Staff time requirements for irrigation systems audit

To evaluate different irrigation systems requires different amount of time. The complexity of the system, the needed travel time, etc. are some factors that affect the duration of an evaluation. During a full field evaluation, the staff must record the field measurements, analyze those data and compose a detailed report where it could be described the performance of the irrigation system and proposed the steps that improve the operation of the irrigation network (Putnam, 2010).

Usually, an end-user auditing procedure takes 2-3 hours to complete and it is recommended to take place during the peak of irrigation season (Mulcock et al., 2009).

Equipment and Materials A list of field equipment necessary for the evaluation of most irrigation and drainage systems is shown in Table 9. This equipment will allow the measurement of flow, pressure, discharge rates and application rates for most systems.

Table 9 Equipment for audit teams Equipment type Quantity

1 Vehicle 1

2 A folder which can be used as a support for keeping notes -

3 Design tools (pencil, rulers etc) -

Tablet with WiFi and GPS capabilities (applications/software: scan, stopwatch, 4 1 unit converter, calculator, word processor, spreadsheet and GIS)

5 Pressure gauge with pitot tube 1

6 Pressure gauges (0-15bar) with screw adaptors 2-4

Flow-Pressure meter (for pipe diameters up to 1''). Adaptor for 1'' pipes and 7 1 spare sealing rubbersmay also needed.

8 Ultrasonic flow meter for larger diameter pipes 1

9 Portable wind meter 1

10 Special rulers for measuring depth and volume at catch-cans 1-2

Pre-numbered CatchCans (250 and 1000ml, probability for wire or rope stands 11 40-80 or hangs).

12 Vernier caliper to measure pipe diameters and other component's dimensions 1

13 Handheld soil moisture probes with reading device 1-2

14 Paintbrushes to clean soil moisture sensors 1-2

15 EC, pH meter 1

16 Pair of VHF 1

17 Tape measure (30 and 100m ) 1-2

18 Marked rope (150m) 1

19 Soil auger 1

20 Photo camera (preferably waterproof) 1

Survey equipment for checking height differences - slope (conventional optical 21 - levels)

Other: Protection gloves, boots or plastic shoe protection bags, mattock, shovel, trowel, pruner, various tools (screwdrivers, pruning scissors etc.) and fittings for connecting measurement devices like pressure gauges to the irrigation system, containers for soil samples, 2x volumetric cylinders of 100-250ml with reading per ml to measure water volume, 2x funnels, rope, wire, pliers, clothe and clothes, mark tape (to mark catch cans position in field), sticks (to mark soil moisture measurement points).

Fig. 45 IRMA audit tool case

Notes

The following advices may be very useful when audits are applied: 1. The tablet should be loaded with applications for: location finding, voice recording, calculator, unit conversion, scanner etc.

2. A tool case with typical plumbing tools is needed.

3. Keep everything in boxes. Use one or more boxes with handles in order to keep the equipment in order and easily transport it.

4. Type and stability of catch cans. Special catch-cans for irrigation auditing are available in the market. Nevertheless buckets can also be used. Precaution should be made regarding the stability of the catch-cans. Special catch-cans have either a metal support base or their feet are constructed in such way that will enter a bit in the ground. Some times for example in dense lawns this is not easy to do and special care regarding stability should be made.

5. Store catch-cans according to numbering.

6. Spare parts of irrigation systems and Teflon will be also needed in case special connections or repairs are needed.

7. Do not forget to check/replace the batteries or charge all the equipment (tablet, VHF, sensors etc.) that work with batteries.

8. Do not forget the photo camera. Photos permit the analysis of data and the spotting of areas which face problems in big areas like agricultural cultivations and golf courses.

9. Do not forget the topographic design or in case of missing it, a sketch of the irrigation network, preferably printed in A3 paper size, scaled and indicating north for facilitating fieldwork.

Software

SPACEPROTM

SPACE PROTM was developed at the Center of Irrigation Technology of Fresno State University. SPACE Pro (Sprinkler Profile And Coverage Evaluation) is an analytical tool giving irrigation designers the ability to evaluate and compare sprinkler designs (Oliphant, 2014). It allows designers to represent the sprinkler heads layout; calculate the uniformity and then display the coverage using actual sprinkler test data. Designers can make economic comparisons of different sprinkler layouts to assess the feasibility of upgrading an existing system or choosing a new system (Fig. 45).

Fig. 46 Indicative screenshots from SPACE PROTM software

CROPWAT & ETo Calculator

CROPWAT is a decision support tool developed by the Land and Water Development Division of FAO. It is used for the calculation of crop water needs and irrigation requirements based on soil, climate and crop data. In addition, the program allows the development of irrigation schedules for different management conditions and the calculation of scheme water supply for varying crop patterns. CROPWAT can also be used to evaluate farmers’ irrigation practices and to estimate crop performance under both rain fed and irrigated conditions.

Fig. 47 CROPWAT logo The software can be downloaded for free from: http://www.fao.org/nr/water/infores_databases_cropwat.html

FAO has also developed a simple ETo calculator which can be downloaded for free from: http://www.fao.org/nr/water/eto.html

AQUACrop

Fig. 48 AQUACrop logo

This software applies the procedures of Crop Yield Response to Water model (Renault et al. /FAO Paper 63, 2012). The web page of the software is: http://www.fao.org/nr/water/aquacrop.html

USDA Soil Texture Calculator

Available from USDA (U.S. Department of Agriculture), the Soil Texture Calculator is available in both online and in MS-Excel spreadsheet form.

The web page of the software is: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/?cid=nrcs142p2_054167

UC Davis BIOmet Irrigation Scheduling

This is a collection of calculators that facilitates various procedures. The available calculators are:

• Low-Volume Irrigation Scheduling of Citrus

• Irrigation Scheduling for Citrus

• Irrigation Runtime Calculator for Drip and Micro-Sprinklers Systems

• Computing Distribution Uniformity for Irrigation Management of Citrus

• LIMP – Landscape Irrigation Management Program

• BIS - Basic Irrigation Scheduling

They can be downloaded from: http://biomet.ucdavis.edu/irrigation-scheduling.html

NETAFIM HydroCalc

This is a simple to use, free tool for designing micro irrigation systems.

It can be downloaded from: http://www.netafim.com/service/hydrocalc-pro

Irrigation Association’s Calculators

A set of MS-Excel spreadsheets, namely:

• Auditing and scheduling calculator

• Dripline calculator

• Pipe sizing calculator

They can be downloaded for free from: http://www.irrigation.org/Resources/Tools___Calculators.aspx

Solar Energy Calculators

Bellow there is a selection of solar energy calculators which can be useful when preparing irrigation schedules:

• https://eosweb.larc.nasa.gov/cgi-bin/sse/[email protected]

• https://eosweb.larc.nasa.gov/cgi- bin/sse/grid.cgi?email=skip%40larc.nasa.gov&step=1&lat=32&lon=&submit=Submit

• http://solarelectricityhandbook.com/solar-irradiance.html

Irrigation Cost Calculator

This useful calculator has been developed by the Department of Primary Industries of New South Wales Government (AU), and it is available online at: http://www.dpi.nsw.gov.au/agriculture/resources/water/irrigation/costs/cost-calculator

Rainbird on line Calculators

Rainbird offers a valuable series of calculators at: http://www.rainbird.com/landscape/resources/calculators.htm

Notes

Performing an audit at end-user level – a step by step presentation using the IRMA workbook This workbook can be used for auditing: • agricultural cultivations irrigation systems (open field and under cover) • public and private landscape irrigation systems / recreation (parks, campuses, institutions, parks, sports facilities (golf, football, tennis, etc.), tourist and recreational facilities, private gardens etc.)

Structure and general instructions The proposed end-user level audit includes the following sections:

A. Gathering of detailed information regarding the irrigation/drainage system. B. Preparation of materials (designs, equipment) needed for field work. C. Field work for system audit. This process can be repeated one or more times within a period of few days in between, depending on the needs of the case. D. Writing the final report on the status and management of the irrigation system (comments on construction and condition, presentation of data uniformity, comments on irrigation program, etc.) and on drainage, plus recommendations on improvements in installations and management. E. Briefing on the results and completion of internal sheet on audit parameters. Hand analysis results to manager and data collection sheet in order to collect data for next audit.

General instructions:

• Establishing a friendly yet professional contact with the person in response. • Field work needs at least two people available. More people may be needed depending on the extension of the area, the complexity of the system etc. • Be sure that you have prepared all the necessary equipment for the auditing. • Gathering of information before visit on site saves time. Part of the information needed can be acquired by telecommunication (telephone, email etc.) before the visit to the field. • Cells colored in light gray are used to fill data or make a selection by circling (O) the option that fits the situation. • When multiple choices are available, the relevant check box (□) should be checked (√ or O could be used). • The meaning of B, M, F and E is: B: Bad; M: Moderate; F: Fair; E: Excellent • For every component that is referred during the process ask for or find documentation (manuals, leaflets etc.) and indicate on the worksheet if they were available. • The left column, under the green cell with entitled “manH and other costs” is used for notes regarding how long (in man hours) it took to complete every part of the procedure and if there was any other cost. This column is for internal use in order to provide information regarding the cost of an audit. • The label “Photos □” is a reminder to the auditors to get photos of crucial system parts. If photos have been taken the box is expected to be checked.

• If a scanner application is available any documentation material is acquired in electronic form. • For extra comments, use the Notes part (bottom of page). It is suggested that every comment is numbered in order to be easier to be used after the audit.

Fig. 49 A good relationship with the farmer / irrigation manager is a “sine qua non” parameter of a successful audit

Notes

Α, B, C: Basic system characteristics, system operation evaluation and uniformity measurements

The “Start audit” worksheet

The following information has to be filled:

1. Documentation regarding the realization of the audit. At the left top of the worksheet, the manager of the system signs declares that the system was audited (My system got audited) and that they were informed about the audit outcomes (I received the audit results).

2. Auditing team members (chief inspector’s name should be placed first)

3. Contact information:

• Organisation (name of the company, the municipality etc.)

• Name and age (of the contact person)

• Position of contact person (Owner, Subcontractor, Manager, Other, etc.)

• Address , Telephone numbers and other contact information (website, email etc.)

The auditor is encouraged to make a first telecommunication with the one in response for the system in order to explain the procedure and try to collect as much basic information as possible. During this contact the following questions should be posed:

• Have you filled an irrigation survey questionnaire of IRMA project? (Check Yes or No)

o If the answer is positive, a copy should be inquired by the relevant contractor and most of the required information can be acquired from that and prefilled.

o If the answer is negative, a communication with the relevant contractor should be made in order to register this system.

• Are the following available and if yes could you make copies and give them to the team during the audit? (Check Yes or No and write comments if any):

o Topographic or a coverage diagram

o Plan of the irrigation and drainage system

o Pumping system / grid connection design

o Manuals of the system's basic components (i.e. pump operation diagram)

o Electric power accounts of the system

o Bills from the Local Land Reclamation Service (LLRS) or other similar

o Latest soil and/or water analysis available

o Latest statement regarding EU agricultural funding

o Registrations of the cultivation system (i.e. integrated management)

o Reports from previous audits At the end of this contact you should set the appointment for the audit. The selection of the date should be based take account weather conditions forecast. In case of sprinkler system, it is recommended to select not intensely windy conditions. For accurate results note that collection of data should be time independent to prior irrigation of the study area.

Do not forget to call the day before to confirm appointment.

Notes

The “Site and System characteristics” worksheet

The date as well as the time of arrival and departure from field are filled at the top of the first page.

In case that the field belongs in the area of an irrigation scheme (GLRS, LLRS etc.), the name of that organization is filled.

The geographical coordinates (location) are inserted (latitude and longitude in degrees). At the right an equation converts degrees to (o, ‘ and ‘’).

The following information has to be filled:

• Type of setup (check whether it is public or private and if it is an open field, a greenhouse / nethouse, a Landscape (turfgrass, shrubs, trees) or an athletic installation)

• Basic system use

o Irrigation

o Frost protection

o Other

• The area of the filed (ha)

• The system designer (a craftsman, an agriculturalist, the owner or other)

• The system constructor (a craftsman, an agriculturalist, the owner or other)

• The system conservator (a craftsman, an agriculturalist, the owner or other)

• The system administrator (a craftsman, an agriculturalist, the owner or other)

Then a list of probable operational problems is given and the system manager is asked whether they are faced or not. The list contains issues regarding: Low or High pressure; Tilted sprinklers; Sunken sprinklers; Spray deflection; Arc misalignment; Drainage from low placed sprinklers; Different outlets at the same zone; Missing or broken components; Clogged components; Leaky seals or fittings; Pipe leaks; Slow drainage / ponding / surface runoff; Compaction / thatch13; Other malefactions etc.

In case of a previous audit, it must be checked whether the proposed improvements and repairs have been made before proceed to the new audit.

13 Thatch is a tightly intermingled layer of living and dead stems, leaves, and roots which accumulates between the layer of actively growing grass and the soil underneath. Thatch is a normal component of an actively growing turfgrass, and as long as it is not too thick, it can increase the resilience of the turf to heavy traffic. Thatch develops more readily on high-maintenance lawns than on low-maintenance lawns.

Zone ..... POC

WS .... Zone ..... POC

Main line sketch WS ....

Zone ..... POC WS ....

Zone ..... POC

Fig. 50 Basic system layout (“Site and System characteristics” worksheet)

A basic sketch (Fig. 48) containing the system layout and the system surroundings that affect irrigation should be designed. If the auditor finds more convenient a satellite or aerial view of the site could be used as a background. Also if the auditor has already acquired a design of the area or the system, this can be used. The sketch should contain information regarding the location of the Water supply/ies) (WS), the mainlines, the zones/stations (A, B, C, etc.) of the system, the location of the various components etc. On the design the north direction and basic dimensions are also expected to be placed.

The system is thought to be composed by (Irricad, 2014):

• a number of zones which include zone (or sub main) pipes and laterals (pipes on which the outlets are connected), each zone runs a specific irrigation schedule

• a mainline which connects the zones to the water supply (ies)

• control valves through which zones are connected to the mainline system.

Information regarding water supply / POC (point of connection) characteristics is registered:

• Source type

o Irrigation canal

o Water pond / tank

o Drilling (depth (m) and pipe diameter (''))

o Civil water system

o Other

• Irrigation rules (bans, irrigation time windows etc.)

• Water meter (yes or no and its characteristics i.e. type, diameter etc.)

• Condition of water supply / POC area

In every case any documentation material is acquired.

If irrigation water usage/cost, data are available for the period before the audit, the relevant fields are filled with the amount of water used for irrigation (in m3). An alternative information could be the total hours per year that the system irrigated (if the latest is multiplied by the average flow rate, an estimation regarding the consumption will be available).

In the same framework, data regarding cost for irrigation (labor and materials) is available is asked. In every case any documentation material is acquired.

If a pump is used, relevant information is asked:

• Pump documentation (mainly the pump diagram), manufacturer, type / model, age, Power / max RPM (in HP and rpm respectively), typical operating flow and typical operating pressure

• Motor documentation, manufacturer, type / model, age

• Pressure tank existence (and its characteristics)

• Other

In cases of special systems like for example the use of a larger capacity pump which fills with water from a drilling a tank and a second smaller pump which is activated when the system works relevant notes should be kept and data for both pump should be registered.

In every case any documentation material is acquired.

The energy source is then registered: petrol, gas, electricity or other. Also a power system diagram is asked. Finally the condition of the power supply system is evaluated.

Regarding energy cost, data regarding the annual cost (€ y-1) or the typical energy consumption per hour is registered. This information can be used in combination with the applied schedule data from the Zone characteristics worksheet in order to estimate the annual energy cost. In every case any documentation material is acquired.

Notes

Regarding main filters, which are typically placed near POC, the order of the various components is registered (i.e. ① hydrocyclone, ② mesh filter, ③ …) along with the characteristics of each of the (i.e. mesh or color). The typical filter types are: hydrocyclone, sand filter, mesh filter, disk filter, reverse osmosis etc. In every case any documentation material is acquired.

Fig. 51 Filter selection quick reference (IA, 2007b) Other key components at the POC (i.e. check valve backflow preventer, air valve, etc.) should be also registered along with information for their conditions, their characteristics, their placement etc. In every case any documentation material is acquired.

This area can be also used for the registration of various components of the system independently of their location (i.e. flush valves etc.).

Information regarding the main pipes (material, pressure range) and depth of installation is also registered in this worksheet. The relevant information includes:

• Section (initial - final length in m) for example 0 – 50 mean the first 50 m from the POC, 50- 20 the next 20m. This is because most times mainlines use a telescoping profile in order to mitigate variation of flow along their length.

• Diameter (Ø in mm) which is filled in the appropriate column, referring to the pipe material PVC, PE(LDPE), PE(HDPE)

• Pressure (Schedule, bar or atm))

• Height (initial - final in m), which in case of underground system has a negative value (i.e. 0.2 for a pipe buried 0.2 m under the ground surface).

The worksheet requires also information regarding the irrigation system zones (stations). For each zone the identification letter is provided along with the relevant system type code (OF: Open field; G/N: Greenhouse / Nethouse; L: Landscape (turfgrass, shrubs, trees); A: Athletic), the slope (%), the number(s) of the soil sample(s), the area (m2) and the irrigation system type (sprinkler, micro, other), the plant material, the plant material similarity (for example for a cultivation of orange tress all the plants are the same and tick is expected in this field, but for a flower bed with various plant that have different irrigation needs this field should be left blank), the yield (kg, pieces, etc), the distance between crop rows (m) and crops on each row (m) or the planting density (plants per area unit) and the establishment (planting) year.

Finally information regarding environmental aspects is asked. For each zone information regarding fertilization (time of application, fertilisers, kg per plant, kg per ha, if it was based on soil analysis results or not, etc.), plant protection, weed removal using chemical means (enemy (pest, weed etc.), time of application, pesticide, method of application, quantity per ha, if it was based on advice by a professional agriculturalist or not, etc), plowing, weed removal using mechanical means (machine type, time of application, depth (cm), etc.) and other cares (type of care (cuttings (indicate also height of grass), aeration, thatch removal, ponds formation etc.), time of application, etc.).

The “Legislation” worksheet

This worksheet registers whether the system is in accordance with the relevant legislation and it depends of the country of application.

The “Zones Stations characteristics” worksheet

This worksheet is used to register information regarding the separate zones of the system. A separate sheet should be used for every zone. For special cases like football fields etc., specific sheets have been prepared.

Soil sampling data should be placed in the relevant field. There are fields for the depths of 0-30 and 30-60cm as well as for other depths. For example for turf grass only the 0-30 cm sample is need but in the case of tree cultivation it is recommended to sample at least the first two layers. Notes on soil layering should be kept at this point. This step can be skipped in case that a recent soil analysis is available.

Table 10 Values for soil characteristics (FC, WP from USA Soil Texture Classification from FAO p56; Basic if from FAO Tm5 - Brower et al., 1985) Basic infiltration FC WP AW = FC - WP Soil type rate m3/m3 m3/m3 m3/m3 mm h-1 Sand 0,07 - 0,17 0,02 - 0,07 0,05 - 0,11 50,000

Coarse Sand

Medium Sand

Fine Sand

35,960 Loamy Sand 0,11 - 0,19 0,03 - 0,10 0,06 - 0,12 40,000 Sandy Loam 0,18 - 0,28 0,06 - 0,16 0,11 - 0,15

Fine Sandy Loam

V. Fine Sandy Loam

22,568 Loam 0,20 - 0,30 0,07 - 0,17 0,13 - 0,18 16,373 Silt 0,28 - 0,36 0,12 - 0,22 0,16 - 0,20 25,000 Silty Loam 0,22 - 0,36 0,09 - 0,21 0,13 - 0,19 39,537 Sandy Clay Loam

15,000 Clay Loam

3,885 Silty Clay Loam

38,154 Sandy Clay 0,30 - 0,37 0,17 - 0,24 0,13 - 0,18 1,000 Silty Clay 0-30 - 0,42 0,17 - 0,29 0,13 - 0,19

Basic infiltration FC WP AW = FC - WP Soil type rate m3/m3 m3/m3 m3/m3 mm h-1 7,000 Clay 0,32 - 0,40 0,20 - 0,24 0,12 - 0,20

A sketch of each zone will facilitate the analysis. It is recommended to select the proper template to sketch the zone arrangement (Fig. 52). At the sketch both the irrigation and drainage system should be depicted layout along with basic technical information. Zone borders, North direction (Ν), basic dimensions, head components, pipes, locations and number of outlets (number of outlets per lateral), other components and any other useful indication or comment should be provided.

Fig. 52 Generic zone sketch (system zoomed in at zone scale) and sketch of football field irrigation and drainage system

For each zone information regarding the following components should be registered:

• the control valve (manufacturer, model, flow range, pressure range, condition (of valve and valve box)

• the system control (manual control, irrigation controller etc.). In case that a controller is used the following data should be acquired (manufacturer, model, age, number of stations, type of power supply, number of programs, number of start times, if a rain delay feature exists, if water budget feature exists, if a pump control position exists, if ports for sensor(s) exists). Also some notes regarding wiring are expected.

• the sensors that are used to manually monitor irrigation related parameters (i.e. tensiometer, handheld soil moisture sensor etc.) or the sensors that are plugged to the controller (i.e. rain sensor, soil moisture sensor, wind senor

• the zone filter (type, manufacturer, model, mesh or color, flow range, pressure range, condition

• probable fertilization equipment

• other components like pressure regulator, air valve, flush valve etc.

• pipes (zone pipes and laterals)

Regarding outlets, the worksheet contains different areas for the different types of outlets:

• Big guns / travelling irrigators characteristics (manufacturer, model, operating pressure, flow rate, condition)

• Sprinklers and micro-sprinklers characteristics (manufacturer, model, nozzles number, type, P, Q (units) per wetted arch (90o, 180o, etc.), wet radius, layout type (square, triangular etc.), distance between, condition)

• Drippers / Emitters and Driplines characteristics (type (individual emitters, driplines, drip tapes etc.), manufacturer, model or pressure/flow, special characteristics (pressure regulated, self-cleaned etc.), installation distances (height, on pipe or dripline, between pipes or driplines), condition).

Regarding the applied schedule the auditor fills information whether it is done manually and the relevant frequency and duration, or using a controller and in this case the scheduling parameters (start times, frequency, run time and sensor adjustment) are registered.

Also information regarding the drainage system has to be provided (type i.e. drainage ditches / canals, underground pipeline system , layering with coarse grained materials etc., relevant problems and where does the runoff goes).

For the special case of greenhouse / nethouse a number of additional characteristics should be registered: manufacturer, type of structure (arc, arc with side walls, sloped roof), covering material, year of construction, number of rows, row dimensions, whitening / shading and relevant shading period and percentage, climate control infrastructure, fertigation, hydroponics, etc.).

Notes

The “Uniformity test” worksheet

Before applying the uniformity test all the obvious system / zone problems should be noted and repaired.

Typically the test should be repeated after all the suggested improvements by the audit have been applied.

A separate worksheet should be used for every zone.

Fig. 53 This catch-can proved to be very small for the discharge rate of micro-sprinklers of that system. This means a lot of wasted hours (Kolomodia, Arta, 2014)

The soil moisture sensor that will be used along with any calibration equation should be noted.

The type of catch-cans their throat area –and diameter in case of circular throats- should be noted.

The catch-cans should be placed in predefined position and the relevant catch-can number should be noted in the sketch.

The tests must be conducted at normal operating conditions using the appropriate flow and pressure gauges. Pipes and outlets at indicative laterals of the system (at the beginning, middle, and end of every zone) must be audited. Before the initiation of the audit these components should be numbered.

In order to avoid cases where the running time of the program is very small or very large compared to the capacity of the pots, theoretical estimation of the expected volume of water of the catch-can in relation to the run time of the system during the test is recommended. The actual test time should be noted (Fig. 53).

The following activities should be made in the framework of the test:

1. Measurement of soil moisture in predefined locations before the initiation of the audit irrigation

2. Detection of problems during the audit irrigation

3. Measurement of pressure and flow at selected locations during the audit irrigation

4. Measurement of the water volume in the catch – cans after the audit irrigation

5. Measurement of soil moisture in the predefined locations after the audit irrigation

Notes

For the registration of these audit data either the relevant tables or the generic or special sketch prototype can be used (Fig. 54, Fig. 55).

N arrow

Laterals with id Number of plants rows between laterals Catch can location

Fig. 54 Generic Zone sketch (system zoomed in at zone scale). Instead of the table you can use the boxes to note catch-can number, volume, moisture around etc.for each catch-can location.

During operation of the system observation regarding zone problems should be made and for the selected outlets the operating pressure, the radius (for sprinklers) and the pipe flow rate should be measured. Typical problems that may be detected include: improper zoning, limited controller capability, incorrect pressure (low / high), lack of adequate flows, improperly sized components, old or worn out equipment, dirty or teared filters, tilted sprinklers, spray deflection, sunken sprinklers, plugged equipment, arc Misalignment, drainage from sprinklers located at lower parts of the system,

97 leaky seals or fittings, lateral or drip Line Leaks, missing or broken heads or emitters, slow drainage or ponding, compaction/Thatch/Runoff etc.

The indications of the soil moisture sensor before and after the audit irrigation and the volume of the collected water in the catch cans should be noted. The difference in soil moisture is automatically calculated.

25 catch-cans N arrow

Fig. 55 Typical catch-cans placement for a football field. Instead of the table you can use the boxes to note catch-can number, volume, moisture around catch-cans etc.

For sprinkler zones 1. In case of sprinkler systems wind speed should be monitored also during the test if variations are sensed. The wind speed at 2m: should be < 8 km/h (4.97 m/h). The relevant indications should be registered.

2. Creation of a grid by placing denser mesh around some characteristic sprinklers. Numbering the positions of pots (the substrate moisture measurement locations should be around each pot) on the design.

3. Minimum 20 catch-cans per station

4. Placing catch-cans in designated points

5. Matching point numbers and catch-cans

6. The catch-cans along the edge of the zones should be placed 30cm to 60cm in from the edge.

7. For fixed spray sprinklers - near a head and half-way between the heads

8. For rotor heads, less than 12m radius - near a head and 1/3 of the distance between the heads

9. For rotor heads, greater than 12m radius - near a head and 1/4 of the distance between the heads

10. Large areas (i.e. football fields), rotor sprinklers grid, 5+ m spacing

11. Small areas (i.e. narrow turf area less than 2m wide), spray sprinklers grid 1.5-2.5m spacing

12. Before irrigation

a. The system should initially operate for 1-2min to assume that the pipes will be full of water.

b. Before test irrigation, perform substrate moisture measurements at 1-3 points, 10- 20cm from each catch-can.

c. Placement of catch-cans or turning them to the right position.

d. Record indication of electricity supply counter or of fuel tank level as well as this of the water meter.

e. Probably the consumption during audit will not be traceable.

f. Operation of the irrigation system for 10-30min (depending on the capacity of the pots and based on estimates that have been made). Alternatively gradual operation.

13. During irrigation

a. Keep time when system is operating, do not trust the controller's time set up (mainly for short op. times)

b. Flow rate measurements at pipeline's selected points (if possible)

c. Pressure measurements at selected points and outlets

d. Inspection of valve boxes and sprinklers, pressure measurement at selected nozzles, checking for any leaks, the wetting radius, coverage problems, drop size, etc.

14. Stop irrigation and measure volume or level in each catch-can

a. At the end record indicator of electricity supply counter or of fuel tank level plus water meter.

b. 5-20 min after irrigation, resume the substrate moisture measurements. 5-20cm away from sprinklers or for the case of microirrigation at the initial measurements spots.

The following should also be taken into account when planning and performing the test:

• It is suggested that water in catch-cans be read in cm (vertical) or milliliters (ml) and it is recommended that a minimum of 25 ml of water be collected.

• When the test area is served by multiple stations, the station run times must be adjusted to achieve matched precipitation across the test area.

• Rotor sprinklers must run for a minimum five rotations during the test.

• Complete inspection sheet, design and photos.

• Special case: Upwind-Downwind Ratio Test. Using a measuring tape, measure the throw of the water upwind from the sprinkler, which is the water that is going against the wind. Then, measure the throw of the water downwind, or with the wind. Then divide the upwind distance by the downwind distance (upwind / downwind). The resulting ratio should have a value of 0.75 or more in order to proceed with the catch device test. Remember that this is only a guide and the real question is whether wind speeds are consistent with typical irrigation times.

For micro-irrigation zones 1. Check the selected for catch-cans places. Number the positions of the cans (the substrate moisture measurement locations should be around each can) on the design.

2. In order to avoid cases where the running time of the program is very small or very large compared to the capacity of the cans, theoretical estimation of the expected volume of water of the catch-can in relation to the uptime of the system is recommended.

3. Placing catch-cans in designated points

4. Matching point numbers and catch-cans

5. Minimum 20 catch-cans per station

6. There is the possibility for the case of drip lines or tapes for water to leak out the can and in this case special configuration or some digging maybe needed.

7. Before irrigation.

a. The system should initially operate for 1-2min to assume that the pipes will be full of water.

b. Before audit, substrate moisture measurements at 1-3points, 10cm from other close dripper (mark the spot with a stick or other). Also in case of linear dense plantations mark the rows where you have put cans.

c. Placement of catch-cans or turning them to the right position.

d. Record indication of electricity supply counter or of fuel tank level as well as this of the water meter.

100

e. Probably the consumption during audit will not be traceable.

8. Operation of the irrigation system for 10-30min (depending on the capacity of the pots and based on estimates that have been made). Alternatively gradual operation.

9. During irrigation

a. Keep time when system is operating, do not trust the controller's time set up (mainly for short op. times)

b. Flow rate measurements at pipeline's selected points (if possible).

c. Pressure measurements at selected points and outlets.

d. Inspection of valve boxes and outlets, pressure measurement at selected outlets, checking for any leaks, drop size, etc.

10. Stop irrigation and measure volume or level in each catch-can.

The following should also be taken into account when planning and performing the test:

• Microirrigation systems should be monitored to detect clogging or other maintenance issues and to check the volume of applied water for irrigation scheduling purposes. Pressure gauges and flow meters are excellent monitoring tools. Readings from pressure gauges on the downstream and upstream sides of filters can detect when a filter is dirty and needs to be cleaned. Monitoring and keeping flow meter records can detect clogging in emitters, since the flow rate drops as the emitters clog. Emitter clogging can be caused by participate matter such as sand, chemical precipitates such as lime or iron, or biological growths such as algae or bacterial slime. Good filtration is a major factor in solving all clogging problems. Typical clogging situations concern:

o Particulate matter clogging can usually be solved simply with good filtration. Preventing biological clogging requires good filtration, usually sand media, along with periodic use of a biocide, such as chlorine, injected into the irrigation water.

o Lime (calcium carbonate) precipitate clogging requires the addition of acid materials to lower the water pH and dissolve the lime deposits. Lime clogging can often be handled with periodic pH adjustment or adjustment only for the last portion of each irrigation, but serious lime clogging may require continuous pH adjustment.

o Iron precipitate clogging is difficult to solve. The most common solution is to place water in a pond or reservoir and allow the iron precipitate to settle out before using the water for irrigation.

• It is suggested that water in catch-cans be read in cm (vertical) or milliliters (ml) and it is recommended that a minimum of 25 ml of water be collected.

• At the end record indicator of electricity supply counter or of fuel tank level plus water meter.

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• 5-20 min after irrigation, resume the substrate moisture measurements at the initial measurements spots.

• Complete inspection sheet, design and photos.

Special cases:

• Channels and pots: Drainage can be also measured in order to estimate leaching fraction

• Sub-irrigation systems: Use of soil moisture sensors instead of cans and comparison of expected with measured by water meter water volume for leaking detection (the latest is of great interest as the system cannot be seen).

Cooperation level At the end of the test, the cooperation level of the person is response is noted by designing the lips at the face.

System and site restoration A number of modifications is probable to be made during the preparation of an audit which will require the use of appropriate fittings. A list of fittings that have been used at the audited system and must be replaced at the toolbox should be made at this stage.

Finally, all professionals should live each place at least as they found it. All mess should be restored and garbage should collected and left in a proper place.

Water quality, quantity and pressure measurements

A special section in this worksheet regards registration of measurements regarding the characteristics of the water source.

For a generic assessing of the qualitative characteristics of the water source the pH and the Electrical conductivity (EC, dS m-1) are measured on site.

102

Head (pressure) and flow rate couples are measured at the water supply. The static pressure (flow rate =0) is initially measure and then by progressively open the water supply a number of couples, up to the maximum available flow rate are registered.

The following table and diagram (Fig. 56) present an example of measured head / flow couples by auditor. A linear regression line provides all the information needed to realize at which point the system is expected to operate.

Head (bar) Flow rate (l min-1) Flow rate (m3 h-1) 4.50 0.00 0 3.50 18.92 1.13 2.75 26.50 1.59 2.00 34.00 2.04 1.40 37.85 2.27 Max available flow rate

Fig. 56 Head / flow couples at water source and relevant linear regression line

In case of more than one water sources the above mentioned measurements are repeated for each one of them.

The “Uniformity test” worksheet for the special case of travelers

For the special case of travelers the following information should be gathered (Fig. 57):

• Nozzle type

• Nozzle age

• Nozzle condition

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• Speed selection / gear

• Vertical angle setting

• Sector angle setting

• Outlet height above canopy

• rw (distribution system wetted radius)

• W (Irrigation strip width, lane width)

• Lt (travel path length)

• End guard length (>rw)

• sc (collector spacing, 6m for guns, 3m for sprayers)

During the audit the following data are registered and measurement are made:

1. Strip number

2. Wind speed (Check and record wind speed at 2m: should be < 8 km/h (4.97 m/h). Wind speed should be monitored also during the test if variations are sensed)

3. Energy consumption: indication at beginning

4. Start time

5. Tsb (beginning stationary operation time) and relevant flow, Q (m3 h-1)

6. Transverse speed test (St) by means of Lendth (m), Time (min) and Q-P couples:

• from initial position to 1st line of catch-cans

• from 1st to intermediate line of catch-cans

• from intermediate to interim line of catch-cans

• from intermediate to last line of catch-cans

7. Tse (end stationary operation time) and relevant flow, Q (m3 h-1)

8. End time

9. Energy consumption: indication at end

10. Longitudinal speed uniformity test (SI). This is an optional measurement during which the time (min) for the traveler to pass each 10m (D) is registered. The peed (m/h) is then automatically calculated.

104

Notes

Fig. 57 Traveler audit data (Irrigation New Zealand, Sustainable Farming Fund, Page Bloomer Associates Ltd, 2010)

105

Notes

106

D: Data analysis and report generation This section includes:

1. Soil characteristics estimation at the laboratory (pH, EC, texture analysis for as many

irrigation zones as needed, CaCO3, Organic matter).

2. Determination of irrigation period and estimation of monthly plant's water needs according to historical climatic data.

3. Calculation of distribution uniformity coefficients (DU, CU, SC or other) using catch - cans and soil moisture data.

4. Development of a theoretical irrigation schedule and comparison with the applied one for each zone.

5. Development of information regarding the design and construction issues of the system.

6. Estimation of the potential savings in water, energy, labor and money after the application of the proposed improvements.

7. Composition of the final report regarding the system, the schedule, the efficiency etc. Proposals for improvement and expected savings.

The “ Substrate and Water” worksheet

Soil characteristics estimation is performed at the laboratory for all the collected samples (the methods that have been used are registered). The measurements concern:

1. The percentage of sand, silt and clay from which the soil type is determined

2. pH, EC, CaCO3 and organic matter measurement

In the framework of IRMA audits the following methods where applied (AELS - University of Georgia, 2014):

• For the mechanical analysis the Bouyoukos method.

• For the measurement of soil pH a soil-water solution 1:2.5 was used while for the determination of EC a soil-water solution 1:5 was used.

• For the measurement of the calcium carbonate (CaCO3) percentage, which refers to the total carbonates which is contained in 100 g of dry soil, a Bernard calcimeter was used.

In case of hydroponic cultivations the type, the manufacturer and the particles size (mm) of the substrate are noted.

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The field measurements for water pH and EC from each source are just copied in this worksheet, and a note regarding their suitability according to the following table:

Table 11 Water quality for agriculture (Ayers et al., - FAO, 1994) pH normal range: 6.5 – 8.4 Salinity (affects crop water availability) Unit Degree of Restriction on Use

None Slight to Moderate Severe EC dS m-1 < 0.7 0.7 – 3.0 > 3.0

The “ Uniformity” worksheet

A separate sheet for every zone of the system should be used.

Information regarding catch-cans’ characteristics, test run time and collected volume of water in each catch-can are copied from the “Uniformity test” worksheet. The

The catch-cans measurements are placed in the 2nd column of the table that is available in the worksheet and sorted in ascending (Z-A) order (the number of each catch-can (1st column) should follow this classification).

The |Vi-Vavg| (absolute value of the difference between each value and the average of all values) and the PR in each can are automatically calculated in the 3rd and 4th columns of the table.

The averages, the totals and the ratios that are needed for the uniformity indices are then calculated, but the relevant formulas need to be adjusted for the number of catch-cans that have been used. The calculations regard the following:

• Low Quarter Average Depth (or Volume)

• Low Half Average Depth (or Volume)

• Overall Average Depth (or Volume)

• Sum of volumes, ΣVi (ml)

• Average precipitation rate, PRavg (mm/h)

Then a number of uniformity indices are calculated automatically:

• The Low Quarter irrigation Distribution Uniformity Index (DUq for sprinkler systems, Eq. 5)

• The Low Half irrigation Distribution Uniformity Index (DUh for sprinkler systems, Eq. 5)

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• The Scheduling Coefficient (SC for sprinkler systems, Eq. 6)

• The Christiansen Coefficient (CU, for both sprinkler and micro-irrigation systems, Eq. 4).

Also a number of descriptive statistics parameters are calculated in this worksheet (maximum, minimum and average collected volume, standard deviation and standard error). The relevant formulas need to be adjusted for the number of catch-cans that have been used.

The analysis could concern the whole or parts of the zone in order to get more analytical image of the situation. The results are then evaluated and a variation of more than ±10% is probably unacceptable and suggests poor system design.

Additionally a rough cross check – pump flow rate / water supply from catch can test can be made using the following equations:

Q = OutNo ⋅ q Eq. 10 Zone flow estimation where Q is the Overall flow rate (L h-1), OutNo is the number of outlets and q is the expected emitters’ flow (L h-1) for the average H (Eq. 3).

The resulted overall flow rate is then compared to the specified pump flow rate and relevant comments are noted.

In this worksheet two graph are also created using the audit results: a) Water volume fluctuation in catch-cans (X: number of catch-cans; Y: water volume (ml)) and b) Substrate moisture before and after irrigation (X: position (around each catch-can); Y: volumetric soil moisture (% v/v))

The “Climate Irrig Period ETo” worksheet

This worksheet is used for registration of the climatic parameters (20-30 years average weather conditions) and the calculation of relevant ETo values. The omvrothermic diagram (Bagnouls- Gaussen diagram from Nassi o Di Nasso et al., 2013) that is also produced in this worksheet allows for estimating the typical irrigation period of the area (Fig. 48).

The worksheet provides equations for the calculation of open field ETo both methodologies provided in FAO p56 (Allen at al., 1998):

• The Penman-Monteith model (Eq. 11) and

• The Hargreaves – Samani (Eq. 12) model

The latest could be used when only air temperature information is available. As it has a tendency to under predict ETo under high wind conditions (u2 > 3 m s-1) and to over predict it under conditions of high relative humidity relevant corrective factors (a, b) are provided.

ETo is calculated in monthly basis. For this a representative day has been selected for each month (Table 12). The representative day is the one during which the theoretical clear sky solar radiation is equal or as the closest to the mean solar radiation for that month.

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Table 12 Representative days for each month for the calculation of average daylight duration and solar radiation for latitudes between -60o and 60o (Koutsoyiannis and Xanthopoulos, 1999) Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Representative day number 18 46 75 105 135 162 199 229 259 289 318 345

For the special case of greenhouses / net houses the relevant approach of Institute Nationale de la Recherche Agronomique (INRA) is provided (Baille, 1999). Valuable information regarding the case of greenhouses in also provided by FAO-AGP and ISHS-CMPC (2013).

It has to be noted for some countries specialized guidelines regarding ET and irrigation period could be available. Greece is an example (GMA, 1989).

900 0,408× Δ × (R n − G) + γ × × u 2 × (es − ea ) Τ + 273 Eq. 11 ETo (Penman-Monteith) ETo = Δ + γ × (1+ 0,34× u 2 ) where ETo is the reference evapotranspiration (mm day-1), Rn is the net radiation at the crop surface (MJ m-2 day-1), G is the soil heat flux density (MJ m-2 day-1), T is the air temperature at 2 m height (°C), -1 u2 is the wind speed at 2 m height (m s ), es and ea are the saturation and the actual vapour pressures (kPa), Δ is the slope vapour pressure curve (kPa °C-1) and γ is the psychrometric constant (kPa °C-1). 0,408 is the conversion factor from MJ m-2 day-1 to mm day-1.

0,5 ETo = 0,408⋅[0,0023× (Tmean +17,8) × (Tmax − Tmin ) Ra ] Eq. 12 ETo (Hargreaves – Samani) where ETo is the reference evapotranspiration (mm day-1), Tmax, Tmin and Tmean are the maximum, minimum and mean air temperatures (°C) and Ra is the extraterrestrial radiation (MJ m-2 day-1). 0,408 is the conversion factor from MJ m-2 day-1 to mm day-1.

Fig. 58 Indicative omvrothermic diagram (Bagnouls-Gaussen diagram from Nassi o Di Nasso et al., 2013) of Arta Greece (based on climatic information from the Hellenic National Meteorology Service)

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The “Sprinkler schedule” worksheet

The procedure that is described in this worksheet is valid for a range of sprinkler irrigation systems (like solid-set systems () that are used in agricultural cultivations, sprinkler systems for landscaping setups etc.). By applying the calculations, the auditor can compose a theoretical irrigation schedule for the zone under evaluation and compare it with the applied one. This theoretical schedule is based on climatic conditions thus it can accompany a zone as a reference but in any case should be applied by taking account the actual weather conditions.

A number of inputs is needed. Namely:

• The area

• The effective depth of rootzone (de, m) and the maximum allowed depletion (MAD, %) of the cultivation. Generic relevant information for these can be found in FAO p56 (Allen et al., 1998).

• Basic soil characteristics like Field capacity (FC, % v/v), Permanent wilting point (PWP, % v/v) and Final infiltration rate (if, mm h-1). Generic relevant information for these can be found in FAO p56 (Allen et al., 1998). From FC and PWP the Available water content (AWC, % v/v) is automatically calculated.

• Basic characteristics of irrigation system like Efficiency (IE, %) the level of which can be estimated using application uniformity results and Precipitation rate (PR, mm h-1) which can be calculated from audit results. From if mm h-1) and PR (mm h-1) the maximum safe run time of the system RTmax can be calculated (RTmax=60∙if/PR). This a run time which is considering safe regarding possible surface runoff (Melby, 1995).

• If the climatic information regarding rain will be taken into account or not. Typical the answer in this is no, but in case of special studies (for example regarding water reservoirs) it could be useful.

Then the application dose (da, maximum allowed volume of water per irrigation event is calculated in mm) is calculated. du = da / IE = AW × de × MAD / IE Eq. 13 Irrigation dose where du is the dose (mm), da is the application dose, the amount of water that actually gets to the plants (mm), AW is the available water (m3 m-3), de is the active root depth (mm), MAD is the coefficient of depletion and IE is the irrigation efficiency

du × IE F = Eq. 14 Irrigation frequency ΕD where F is the frequency of irrigation events (days), IE is the irrigation efficiency and ED is the daily water consumption (mm day-1)

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da × Α da RT = = ΣQ PR Eq. 15 Irrigation duration (run time) where RT is the run time (min), da is the application dose (mm) and PR the precipitation rate (mm h- 1)

A table is used for the determination of the schedule. Its fields (columns) are described below:

1. Month

2. Kc (crop coefficient) which for open field agricultural cultivations can be found in FAO p.56 (Allen et al., 1998) along with relevant periods, in case of landscapes the auditor could use species factor data from UCCE and CDWR (2000).

3. kmc or Ks, this field can be used to enter a stress factor (FAO p.56 – Allen et al., 1998) or kmc, the microclimatic factor for landscapes as determined in UCCE and CDWR (2000)

4. kd or Ks , this field can be used to enter a stress factor (FAO p.56 – Allen et al., 1998) or kmc, the density factor for landscapes as determined in UCCE and CDWR (2000)

5. ΚL, this is the product of Kc∙(kmc or Ks) ∙(kd or Ks), L comes for the generic term landscape (UCCE and CDWR, 2000)

6. ETa is the estimated actual evapotranspiration in mm day-1, as calculated in the “Climate Irrig Period ETo” worksheet. Attention should be made to adjust the equation in order to use results from the selected ETo method (Penman-Monteith, Hargreaves-Samani etc.)

7. Number of days, are the number of days for each month

8. ETa is the estimated actual evapotranspiration converted in mm month-1

9. Rain is the expected by climatic data rainfall in mm month-1

10. Reff is the effective rain in mm month-1. This estimation has been made using the relevant approach of U.S. Bureau of Reclamation as described in Dastane N.G. (1978).

11. Leaching fraction, is the percentage (%) of water that should be removed because of salinity issues (Table 13)

12. Water needs, ED in mm day-1. Leaching factor is taken into account. Effective rain is taken into account only if a relevant selection has been made.

13. Theoretical irrigation span, ΕΑ in days, is calculated by diving the theoretical application dose by the daily water needs.

14. Practical irrigation span, ΕΑ in days is a parameter that the auditor proposes. It has to be smaller than the theoretical irrigation span.

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15. Final application dose, dυ in mm takes account the efficiency of the irrigation system

16. Actual run time RT=dυ/PR in min

17. Required water volume m3 month-1

18. RT check, controls if the proposed run time is greater than RTmax.

At the end the schedule is synopsized in the following:

• F, Frequency (days)

• RT, Run time (min)

• Water Budget (spring, fall). This is a percentage of the run time which can be applied in order to conserve water. Water budget is a feature of most modern irrigation controllers.

Table 13 Recommended leaching fractions (Newman, 2008) EC applied EC leached (dS m-1)

(dS m-1) 3 6 9 12

0.50 0.17 0.08 0.06 0.04

0.75 0.26 0.12 0.09 0.06

1.00 0.33 0.17 0.11 0.08

1.25 0.43 0.20 0.15 0.10

1.50 0.50 0.25 0.17 0.12

1.75 0.60 0.28 0.21 0.14

2.00 0.67 0.33 0.22 0.17

2.25 0.36 0.27 0.18

2.50 0.42 0.28 0.21

3.00 0.50 0.33 0.25

5.00 0.56 0.42

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The “ Micro schedule” worksheet

The proposed approach is the same as the one for sprinklers, except that three more parameters are needed (Michelakis, 1988):

• Percentage of wetted area (%)

• Precentage of soil surface that is shaded by plants during midday (Ps, %) and

• Microirrigation ET reduction factor (r)

Micro-irrigation systems should be flushed on a regular basis, every 2 weeks or at least monthly. Silt and clay particles in water are very small and may pass through filters to settle in the pipelines, particularly in the lateral lines where they can clog emitters. Flush valves installed on the pipelines should be opened and the water should be allowed to flush clean. The lateral lint ends should be opened and allowed to flush clean. If little material is evident at flushing, increase the flushing interval. Very dirty lines should be flushed more frequently.

Notes

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The “ Hydroponic schedule” worksheet

According to Katsoulas et al. (2006) the frequency of irrigation can be dependent on solar radiation measured by a pyranometer which was placed outside the greenhouse. Two parameters are used as input values in the irrigation control system for each treatment, namely: the run time for each irrigation event (RT in sec) and the cumulative solar energy input at which an irrigation event was triggered (SEI in Wh m-2).

The following equations are used in two modes, one based on RGo input and one based on IR input:

Tr E = Eq. 16 Irrigation amount (hydroponic schedule) (1− Dr )⋅ IE where E is the amount of water applied (kg m-2), Tr is the crop transpiration (kg m-2), Dr is the drainage rate (%) and IE is the application efficiency of the irrigation system

Tr = z ⋅ RGo Eq. 17 Crop transpiration (hydroponic schedule) z = Kc ⋅t ⋅ a / λ

-2 where Tr is the crop transpiration (kg m ), RGo is the integral of solar radiation outside the greenhouse (kJ m-2), z is a coefficient, Kc is the crop coefficient, t is the greenhouse cover transmission to solar radiation (%), a is the evaporation coefficient and represents the part of the energy of incoming solar radiation that is transformed to latent heat through transpiration and λ is the latent heat of vaporization of water (kJ kg-1).

The procedure to calculate these values for a given period of interest is simple and outlined below:

1. At the beginning, the expected daily cumulative solar energy, Wh m-2, is theoretically calculated (Mavrogiannopoulos, 1994).

2. The crop water needs in l/plant are estimated according to the relevant literature. This value is divided by the expected application efficiency of the system (Smajstrla et al. 1991) and the desirable leaching fraction in order to calculate the total daily water supply per plant.

3. In order to calculate the volume of water per plant in each irrigation event, information regarding the characteristic moisture curve of the substrate and relationship between the height of the substrate is used (Gizas and Savvas, 2007). The final selection aims to keep the moisture in the medium at the level of easily available water (EAW). This value is then combined with the total flow from emitters that irrigate one plant in order to calculate RT (sec).

4. The division of the total daily water supply per plant by the water volume provided by each irrigation event renders the daily number of irrigation events. This number is then used to divide the expected daily cumulative solar energy in order to get SEI (Wh).

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5. The irrigation period begins by providing water up to container capacity and after that the controller –based on RT and SEI- applies the schedule. The integral of solar radiation intensity, at which irrigation events are triggered, is regularly adjusted aiming at maintaining the leaching fraction close to the desired value.

6. The amount of water applied E, in kg m-2, was calculated using a set of equations (Eq. 16, Eq. 17). Note that ΙΕ was used as it was referred in Baille (1999).

7. Irrigation schedule must also take account the fact that a goal is that hydraulic conductivity remains at high values.

E: Final activities 1. Presentation of the final report.

2. Ask if they would be interested for system repair, tune-up, adjustment and repair. If no, why?

3. Do not forget to fill the internal form regarding the audit procedure.

The “Report for system manager” worksheet

After the audit the auditing team composes a technical report to inform the system manager about the detected problems and the suggestions for improving the system’s operation.

The report is divided to three parts:

• Part I: Irrigation system

o General problems that have been noticed.

o Comments regarding soil and water characteristics.

o Comments regarding design, construction and maintenance of the system.

o Comments regarding distribution uniformity.

o Comments regarding the applied irrigation schedule.

o Proposed repairs / alterations and expected benefits.

o Proposed irrigation schedule and expected benefits.

• Part II: Drainage system

o General problems that have been noticed.

o Comments regarding design, construction and maintenance of the system.

o Proposed repairs / alterations and expected benefits.

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• Attachments

o Analytical soil analysis results

o The audit procedure tables

o Copies of the “System manager diary up to next” worksheet

The “System manager diary up to next” worksheet

This worksheet contains a table that the system manager is proposed to fill and have it available at the next audit. This is essential in “write what you do and do what you write” system improvement procedure and must be very well communicated to the system manager.

One worksheet must be filled for every zone of the system and archive along with any design, manual, bill etc. that is relevant to the system.

The following fields (columns) constitute the table:

• Month

• Schedule parameters

o Frequency (d)

o Duration (min)

• Resources consumption

o Energy (electric power, petrol etc.)

o Water volume (m3)

o Problems encountered (code and/or description)

o Solutions applied

o Concerns

• Yield (kg or pieces)

Water meters are a useful tool for auditors. Water meters allow the irrigation manager to accurately record the water use of the irrigation system. These records are also integral part of documenting ongoing water conservation efforts.

Care should be taken however when dealing with water meters as not all water meters are accurate. Calibrating the meter is a simple procedure that an auditor can perform as part of the audit process. For example, during the field test the initial and final indications of the meter can be recorder and compared to the estimated volume of water that the system used.

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The “Internal Form Audit Cost” worksheet

This worksheet has been designed in order to collect data during the IRMA project audits in Greece and Italy, which could help the project team to assess the cost of the audits and their expected financial return.

It contains fields for registering the cost of the following works:

• Preparation activities

• Travel

• Daily expenditure

• Audit cost (equipment, fittings etc.)

• Soil analysis at the laboratory

• Office work for data analysis and report generation

• Presentation of results -recommendations

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Conclusions, proposals and future trends The goals of this IRMA project deliverable was to develop a well-documented and field evaluated procedure regarding irrigation and drainage audits. In this way, IRMA team is expected to:

• communicate irrigation and drainage good practices to farmers, irrigation managers etc.

• make measurements and provide advices to them regarding the shifting of their system efficiency

• get feedback regarding the auditing procedure

It is sine qua non that audits must be made in a way that makes the farmer or the irrigation manager fill comfortable and confident that will gain from this procedure.

Proposals:

• Both irrigation designers and auditors must be certified in order to be able to contract the design, installation and management of irrigation and drainage project above a certain size, regardless if it is public or private.

• Training sessions must be organized by accredited for this scope entity.

• Full free access to relevant standards should be provided at least to certified designers and auditors.

• The cost effectiveness of audits must be investigated in depth.

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Roh M.Y., Lee Y.B., 1996. Control of amount and frequency of irrigation according to integrated solar radiation in cucumber substrate culture. Acta Horticulturae 440:332–337

Savard, D., 2007. Irrigation Audits for Sports Fields. Irrigation Association. Retrieved 10/2014 from: http://sturf.lib.msu.edu/article/2007sep24.pdf

Smajstra A.G., B.J. Boman G.A, Haman D.Z., Pitts D.J., Zasueta F.S., 1990. Field Evaluation of Microirrigation Water Application Uniformity. IFAS Extention Bulletin 265. Univ. of Florida

Stanhill G., Scholte A.J., 1974. Solar radiation and water loss from glasshouse roses. Journal of American Society of Horticulture Science 99:107-110

UCCE and CDWR (University of California Cooperative Extension California Department of Water Resources), 2000. A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California - The Landscape Coefficient Method and WUCOLS III (WUCOLS is the acronym for Water Use Classifications of Landscape Species). Retrieved 1/2013 from: http://www.water.ca.gov/wateruseefficiency/docs/wucols00.pdf

UF/IFAS (University of Florida), 2014. Irrigation evaluation material (information, basic steps, equipment list). Retrieved 9/2014 from: http://okeechobee.ifas.ufl.edu/irrigation_evaluation.htm

USDA (U.S. Department of Agriculture), 2014. Soil texture calculator. Retrived 9/2014 from: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/?cid=nrcs142p2_054167

Van Halsema G.E., Vincent L., 2012. Efficiency and productivity terms for water management: A matter of contextual relativism versus general absolutism. Journal of Agricultural Water Management 108: 9-15

Wallach R., 2008. Irrigation in Soiless Production (Chapter 3 in: Soilless Culture: Theory and Practice, eds.: Michael Raviv and J.H. Lieth. p. 41-116) Elsevier Publisher

Weynand V.L. 2004. Evaluation of the Application Uniformity of Subsurface Drip Irrigation Distribution Systems. Texas A&M University

Wilson T., 2009. Why Landscape Irrigation Auditing Does’t Work and How to Fix It. Retrieved 11/2014 from: www.h2o-ss.com

Wriedt G., Van der Velde M., Aloe A., Bouraoui F., 2008. Water Requirements for Irrigation in the European Union - A model based assessment of irrigation water requirements and regional water demands in Europe. ENORASIS FP7 project. Retrieved 12/2013 from: http://www.enorasis.eu/uploads/files/Water%20Governance/5.JRC46748_Report_Irrigation_EUR_2 3453_EN.pdf

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Standards ASAE (American Society of Agricultural Engineers), 1996. Field evaluation of microirrigation systems. American Society of Agricultural Engineers Standards, EP405.1, St. Joseph, MI. Retrieved 9/2013 from: http://www.doa.go.th/aeri/files/pht2008/lecture%20slides/mr%20viboon/grain%20drying/aeae- 1998/pdfs/section7/728.pdf

ASAE (American Society of Agricultural Engineers), 2002. Residential Irrigation Uniformity and Efficiency in Florida. American Society of Agricultural Engineers Standards Paper #022246. Written for presentation at ASAE Annual International Meeting / CIGR XVth World Congress Sponsored by ASAE and CIGR Hyatt Regency Chicago, Illinois, USA, July 28-July 31

ASAE (American Society of Agricultural Engineers), 2003a. Design and installation of microirrigation systems. EP405.1, St. Joseph, MI. Retrieved 9/2013 from: http://www.geoflow.com/Flushing/An2%20-%20ASAE%20EP405.1%20Feb%2003.pdf

ASAE (American Society of Agricultural Engineers), 2003b. Field evaluation of microirrigation systems. EP458, St. Joseph, MI

ASAE Engineering Practice (EP) 405.1. 2003 Design and installation

BIPM (Bureau International de Poids e Mesures), 2015. Measurement units: the SI. Retrieved 1/2015 from: http://www.bipm.org/en/measurement-units/

EN 12324-1 Irrigation techniques - Reel machine systems - Part 1: Size series

EN 12324-2 Irrigation techniques - Reel machine systems - Part 2: Specification of polyethylene tubes for reel machines

EN 12324-3 Irrigation techniques - Reel machine systems - Part 3: Presentation of technical characteristics

EN 12324-4 Irrigation techniques - Reel machine systems - Part 4: Checklist of user requirements

EN 12325-1 Irrigation techniques - Centre pivot and moving lateral systems - Part 1: Presentation of technical characteristics

EN 12325-2 Irrigation techniques - Centre pivot and moving lateral systems - Part 2: Minimum performances and technical characteristics

EN 12325-3 Irrigation techniques - Centre pivot and moving lateral systems - Part 3: Terminology and classification

EN 12484-1 Irrigation techniques - Automatic turf irrigation systems - Part 1: Definition of the programme of equipment by the owner

EN 12484-2 Irrigation techniques - Automatic turf irrigation systems - Part 2: Design and definition of typical technical templates

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EN 12484-3 Irrigation techniques - Automatic turf irrigation systems - Part 3: Automatic control and system management

EN 12734 Irrigation techniques - Quick coupling pipes for movable irrigation supply – Technical characteristics and testing

EN 13635 Irrigation techniques - Localised irrigation systems - Terminology and data to be supplied by the manufacturer

EN 908: 1999 Agricultural and forestry machinery - Reel machines for irrigation – Safety

EN 909: 1998 Agricultural and forestry machinery - Centre pivot and moving lateral types irrigation machines Safety

EN ISO 11545 Agricultural irrigation equipment – Centre-pivot and moving lateral irrigation machines with sprayer or sprinkler nozzles – Determination of uniformity of water distribution

GR Legislation, Common Ministerial Decisions 16190/1335/1997 and 19652/1906/1999 (GG Β΄ 519 and GG B' 1575 respectively) regarding the protection of waters from nitrogen.

GR Legislation, Common Ministerial Decisions 43504/2005, 150559/2011 and 146896/2014 (GG B΄ 2878/27-10-2014, GG 1784 Β' and GG 1440 Β' respectively) for the authorisation of using water resources.

GR Legislation, Decision 85167/820, Code of Good Agricultural Practice, Section C (GG Β' 477, 6/4/2000)

GR Legislation, Decisions 145116 and 191002 for the use of reclaimed water (GG Β 354 8/3/2011 and GG Β' 2220 9/9/2013)

Greek Ministry of Agriculture (GMA), 1989. Determination of minimum and maximum limits of the necessary quantities for the sustainable use of water for irrigation (GG 428 Β' 2/6/1989, GMA D. Φ.16/6631)

Greek Ministry of Agriculture (GMA), 1992. Modernisation of the methodology used for the calculation of plants water needs in the framework of relevant studies and adaptation to Greek conditions

Greek Ministry of Infrastructure and Environment (YPEXODE), 1969., Ordinance D24714/20-10-1969 for the determination of minimum and maximum velocity of water in closed pipes.

Greek Ministry of Tourism, 2014. Determination of standards for gulf fields

Greek Standardisation Organisation (ELOT) 2009. 440 Greek Technical Standards (GG Β' 2221/2012)

ICC and ASABE: New Landscape Irrigation Sprinkler Standard

ISO 10522 Direct acting pressure regulating valves

ISO 11419 Agricultural irrigation equipment – Float type air release valves

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ISO 11678 Aluminium irrigation tubes

ISO 11738 and Amendement 1 Agricultural irrigation equipment – Control head

ISO 11738:2000(en) Agricultural irrigation equipment — Control heads. Retrieved 10/2014 from: https://www.iso.org/obp/ui/#iso:std:iso:11738:ed-1:v1:en

ISO 12374 Wiring and equipment for electrically driven or controlled irrigation machines

ISO 13460 Agricultural irrigation equipment - Plastics saddles for polyethylene pressure pipes

ISO 8026 and ISO/DIS 8026 Amendement 1 Agricultural irrigation equipment - Sprayers - General requirements and tests methods

ISO 8224-2 Traveller irrigation machines - Part 2: Softwall hose and couplings - Test method

ISO 8779:2010 Plastics piping systems — Polyethylene (PE) pipes for irrigation — Specifications. Retrieved 10/2014 from: https://www.iso.org/obp/ui/#iso:std:iso:8779:ed-3:v1:en

ISO 9625 Mechanical joint fitting for use with PE pressure pipes for irrigation purposes

ISO 9635 Hydraulically operated irrigation valves (published)

ISO 9644 and Amendement 1 Agricultural irrigation equipment - Pressure losses in irrigation valves -

ISO 9911 Manually operated small plastic valves (published)

ISO 9912-2 Filters – Part 2: Strainer-type filters

ISO 9912-3 Filters - Part 3: Automatic self-cleaning strainer type filters

ISO 9952 Check valves

ISO/CD 13458 Chemical injection tanks units

ISO/CD 15081 Graphic symbols for pressurized irrigation system design

ISO/CD 9261 Irrigation equipment: Emitters and emitting-pipe systems - specification and test methods

ISO/DIS 13457 Agricultural irrigation equipment - Water-driven chemical injector pumps

ISO/DIS 15873 Irrigation equipment - Differential pressure Venturi fertilizer injectors

ISO/DIS 7714 Agricultural irrigation equipment - Volumetric valves - General requirements and test methods

ISO/DIS 8796 Polyethylene (PE) 32 pipes for irrigation laterals – Susceptibility to environmental stresscracking induced by insert-type fittings – Test method and specifications

ISO/DIS 9912-1 Agricultural irrigation equipment - Filters for microirrigation - Part 1: Classification

ISO/FDIS 8779 Polyethylene (PE) pipes for irrigation laterals – Specifications

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ISO/TR 8059 Automatic irrigation systems - Hydraulic control – Technical report

ISO/WD 15886-1 Irrigation equipment - Sprinklers – Part 1: Classification

ISO/WD 15886-2 Irrigation equipment - Sprinklers – Part 2: Design and operational requirements

ISO/WD 15886-3 Irrigation equipment - Sprinklers – Part 3: Uniformity of distribution and test methods

ISO/WD 15886-4 Irrigation equipment - Sprinklers –Part 4: Test methods for durability

ISO/WD 15904 Irrigation equipment - Safety devices for chemigation

ISO/WD Low-pressure, above-ground PVC pipe, both gated and ungated, for surface irrigation

ISO/WD TR 15155 Laboratory test equipment for irrigation purposes – Technical report

New Zealand, Sustainable Farming Fund, Page Bloomer Associates Ltd, 2010. Irrigation Evaluation Code of Practice. Sustainable Farming Fund Project 02-051. Retrieved 10/2014 from: http://irrigationnz.co.nz/wp-content/uploads/2010-INZ-EvaluationCoP.pdf

PrEN 12484-4 Irrigation techniques - Automatic turf irrigation systems - Part 4: Installation, and acceptance

PrEN 12484-5 Irrigation techniques - Automatic turf irrigation systems - Part 5: Testing methods of systems

PrEN 13742-1 Irrigation techniques - Solid set sprinkler systems – Part 1: Selection, design, planning and installation

PrEN 13742-2 Irrigation techniques - Solid set sprinkler systems – Part 2: Test methods

PrEN 13997 Irrigation techniques – Connection and control accessories for use in irrigation systems –

PrEN 14049 Irrigation techniques – Water application intensity - Calculation principles and measurement methods

PrEN ISO 8224-1 Traveler irrigation machines - Part 1: Documentation and laboratory and field test methods

The ministry of Tourism signed the new law (21527, ΦΕΚ 2905/Β/29-10-2014) regarding the determination of golf fields standards for Greece. Among others the text includes information regarding the water resources for irrigation and the irrigation system design, construction and management.

USDA (U.S. Department of Agriculture), 1997. Engineering Handbook Part 652 - Irrigation Guide. Retrieved 10/2013 from: http://directives.sc.egov.usda.gov/viewerFS.aspx?hid=21431

WI (CEN) 00334009 Irrigation techniques - Localised irrigation systems - Filtration

WI (CEN) 00334010 Irrigation techniques - Localised irrigation systems - Hydraulic evaluation

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WI (CEN) 00334011 Irrigation techniques - Irrigation hydrants

WI (CEN) 00334022 Irrigation techniques - Localised irrigation systems - Emitting devices, characteristics and test methods

WI (CEN) 00334024 Irrigation techniques – Meters for irrigation water

WI (CEN) Irrigation techniques - Remote Monitoring and Control for irrigation systems

As the standardization procedure is very intensively evolving it is strongly recommended for irrigation professionals in order to be updated, to frequently visit the web sites of the major international and national standardization organisations along with these of their professional chambers.

Most of these organisations publish electronic newsletters which facilitate professionals to be well informed.

The following list will probably help in this way:

• International Organization for Standardization (ISO), www.iso.org). The Online Browsing Platform of ISO is a very efficient tool (https://www.iso.org/obp/ui/#search). A number of standards are available for free and almost all of them provide some parts from free.

• International Code Council (ICC, http://www.iccsafe.org/)

• European Committee for Standardisation (CEN, https://www.cen.eu/Pages/default.aspx)

• American National Standards Institute (ANSI, http://www.ansi.org/). ANSI also provides a very efficient search engine for standards (NSSN, http://www.nssn.org)

• American Society of Agricultural and Biological Engineers (ASABE, http://www.asabe.org/)

• Irrigation Association / Standards (IA, https://www.irrigation.org/standards/)

• Green Standardization Organization (ELOT, http://www.elot.gr/default_en.aspx)

• Italian Standardization Entity (UNI, http://www.uni.com/)

• European Landscape Contractors Association (ELCA, http://www.elca.info/en/)

• European Society of Agricultural Engineers (EurAgEng, http://www.eurageng.eu/)

• European Irrigation Association (EIA, http://irrigationeurope.eu/)

• Geotechnical Chamber of Greece (GEOTEE, http://www.geotee.gr/)

• Greek Landscape Contractors Association (PEEGEP, http://peegep.gr/)

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Notes

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Annex I Basic units and conversion factors Sizes and conversion factors of units that are commonly used in irrigation audits and relevant calculations are presented in this Annex.

For a complete list of SI (metric) units and their definitions, it is suggested to visit BIPM’s site (2015). Some US/Imperial units are also provided bellow as they are very common in irrigation and drainage practice. Also some local for the project area units are provided.

Length

• 1 m (SI) = 100 cm = 1,000 mm

• 1 m = 3.281 feet = 12 inches

• 1 inch = 2.54 cm

Area

• 1 m2 (SI)

• 1 ha = 10,000 m2

• 1 stremma = 0.1 ha (this unit is common only in Greece)

Volume

• 1 m3 (SI) = 1000 L = 1,000,000 ml

Speed (velocity)

• 1 m s-1 (SI) = 3.6 km h-1

Flow

• 1 m3 h-1 = 16.67 L min-1

• 1 L min-1 = 0.26 GPM

Rain, Irrigation, Evapotranspiration amount

• 1 mm = 1 L m-2

• 1 mm = 1 m3 stremma-1

Energy

• 1 J (SI)

• 1000 J = 0.00028 kWh

Power

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• 1 W (SI) = 1 J s-1

• 1 kW = 1.34 hp

Pressure

• 1 Pa (SI) = 9.87 × 10-6 atm

• 10 bars = 1 MPa

• 1 bar = 0.99 atm

• 1 bar = 14.5 PSI

Converting ml to mm of irrigation

To convert irrigation volume (ml) into irrigation amount (mm), the following equations can be used:

• Generic: h = 0.001 * V / A2, where h is the amount of irrigation in mm, V is the water volume of irrigation in ml and A is the throat area of the catch can in mm2.

• For catch cans with circular throat: h = 0.001273 * V / d2, where h is the amount of irrigation in mm, V is the water volume of irrigation in ml and d is the throat diameter of the catch can in mm.

Online conversion tools The following unit converters is likely to be found useful:

• Generic: http://www.unit-conversion.info/

• Irrigation specific: http://www.rainbird.com/landscape/resources/calculators/ConversionCalculator.htm

• Water potential: http://www.ums- muc.de/en/support/units_standards/water_potential_and_matrix_potential.html

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Annex II End-user level audit workbook The relevant workbook because of its format (MS-Excel) is attached to the manuscript as an external article.

Fig. 59 Screen shot of the IRMA audit MS Excel work book

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Annex III Application example An example audit worksheet is also provided in order to facilitate the study and the application of this guide.

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Back page inside part [intentionally left blank]

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Technological Educational Institute of Epirus (TEIEP) | Faculty of Agricultural Technology

Kostakii Campus, Arta, GREECE

European Territorial Cooperation Programmes (ETCP) Efficient Irrigation Management GREECE-ITALY 2007-2013 Tools for Agricultural Cultivations and Urban Landscapes (IRMA) www.greece-italy.eu www.irrigation-management.eu

ISBN 978-618-80909-9-6

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