Farming in a Land of Extremes Programme

Name:

NZ GRASSLAND ASSOCIATION 76th Annual Conference ALEXANDRA 5-7 November, 2014

FFARMINGARMING ININ AA LLANDAND OFOF EEXTREMESXTREMES

PROGRAMME

ON-FARM FIELD TOUR

Conference Sponsors

The NZGA executive and Local organising committee acknowledges the generous support of the following sponsors

TABLE OF CONTENTS

Welcome 3 Information for delegates 4 Conference Programme 5 Field Tour Wednesday

 Greenfield NZ Pastures Ltd 8  Ida Valley Station 14 - Oversown And Top Dressed Hill Country, D Fastier 26 Field Tour Thursday  Nine Mile Pastoral Ltd 29 - Irrigation Development, Willowbank, T O’Sullivan 35 - A description ofthe OVERSEER® nutrient budget model, Dr A Roberts 37 - Water Allocation in Otago, Otago Regional Council 42

WELCOME

On behalf of the Alexandra Local Organising Committee it is my pleasure to extend to you a hearty Central Otago welcome, to our place… “A World of Difference”. “Farming in a Land of Extremes” encompasses the huge differences that make our region what it is and the vast array of methods adopted by businesses/enterprises to capitalise on them as strengths or overcome them as weaknesses. Be it environmental, climatic, diversity of enterprises, valley floors to high country, dryland to intensive irrigation, old ways and new technology, extremes in all these things are present within our region, but also between us and the rest of the country. Back at the last conference here in 1986, land use change was a hot topic and is prominent again this time round. Not so much focus now on tenure review when compared to the massive rise of the dairy industry, irrigation and Lucerne grazing systems. Tourism was identified back then as a great opportunity and is a major regional industry today, question is where to next? Current hot topics are irrigation; nutrient management; dryland pasture options and hill country development - all have relevance to the three properties we are visiting. I would like to thank the owners and managers of the properties we are visiting for allowing us the opportunity to look inside their businesses and their assistance in compiling the information in this programme. Thanks to Green- field NZ Pastures Ltd, Ida Valley Station and Nine Mile Pastoral Ltd. I would also like to thank the members of the Local Organising Committee for being a great team and doing such an awesome job bringing this conference together. We hope you have a great time, learn heaps and leave happy having spent a few days in our World of Difference.

Best Wishes Vanessa Hore Chair, Conference Organising Committee

INFORMATION FOR DELEGATES the conference organisers no responsibility will be accepted for any losses incurred. REGISTRATION DESK ON FARM FIELD TRIPS Please contact the registration desk for any information or assistance required. Farms that we visit are workplaces and as such there are hazards. We advise all attendees to be The registration desk will be open at the following responsible and exercise due care. times Tuesday 4th Nov 5:00 - 6:30pm NAME BADGES Wednesday 5th Nov 7:30am Name badges should be worn at all times during the Thursday 6th Nov 8:00am conference as they are required for entry to all con- Friday 7th Nov 8:00 am ference sessions, field trips and social functions.

SPEAKERS INSTRUCTIONS VALUABLES All speakers are asked to ensure their presentation Please keep your valuables safe at all times. The is loaded the day before their allocated session organisers of the conference cannot be held respon- times. Please ensure your presentation is compati- sible for any loss or damage of personal items while ble with Office 2007. attending. Your session chair will make contact with you prior to your session. The conference will run strictly to SPECIAL DIETS time. To avoid embarrassment of being interrupted Delegates with special dietary requirements may please ensure you have practiced your presentation need to confirm their requirements with the registra- and can keep to time. tion desk. Oral presentations 12 or 6 minutes

MOBILE PHONES As a courtesy to speakers and other delegates please ensure that mobile phones are switched off during conference sessions, including on field tours. In addition we ask that attendees not photograph presentations due to copyright.

DRESS CODE The standard of dress for conference is tidy casual. For the conference dinner it is smart casual.

DISCLAIMER All information provided is correct at the time of printing. The conference organisers reserve the right to make changes to the programme as necessary.

LIABILITY In the event of circumstances beyond the control of

5 NZGA ALEXANDRA CONFERENCE PROGRAMME Tuesday 4 November 2014 4:30pm to Registration - Cellar Door, 143 Centennial Avenue 6:30pm Wednesday 5 November 2014 7:30am to Registration - Cellar Door 8:30am

8:30am Opening Ceremonies: Vanessa Hore (Chair LOC)

8:35am Welcome to Central Otago: Tony Lepper (Central Otago Mayor)

8:40am 1: A Land of Difference - Farming in Extremes: Chair Warwick Lissaman 8:45am Central Otago - Built on gold, growing on grass (B Wills)

9:05am Challenges facing the farmers of Central Otago (P Garden)

9:25am Integrating lucerne (Medicago sativa) into a high country merino station (D Anderson)

9:45am Sheep performance on perennial lupins over three years at Sawdon Station, Lake Tekapo (G Lox- ton)

10.05am MORNING TEA

10:35am 2: Dryland Farming: Chair Warren King

10:40am Yield and composition of lucerne stands in Central Otago after different winter grazing and weed control treatments (D Moot)

11:00am Nutrient requirements for irrigated lucerne in Central Otago (C Smith)

11:10am An evaluation of lucerne for persistence under grazing in New Zealand (B Harvey)

11:20am Productivity and seedling recruitment of naturalised annual clovers versus sown clovers Trifolium repens and Trifolium subterraneum (T Maxwell)

11:40am BREAK BEFORE BOARDING BUSES FOR FIELD TRIP: 12:00pm Stop 1: Greenfield NZ Pastures Ltd: Legumes and dryland farming

Stop 2: Ida Valley Station: Hill country improvement

5:45 Arrive at Poolburn for BBQ:

8:00pm Depart for Venue

Thursday 6 November 2014 7:30am Registrations - Cellar Door - 143 Centennial Ave

8:30am Warwick Lissamann Presidential Address: Sponsor AgMardt

3: Dairy farming: Agronomy Society: Crop Production Systems 1 - 9:00am Chair Laurie Copland Forages and cereals

Rising plate meters and a capacitance probe estimate Effects of timing of drought stress on grain yield of feed 9:05am the biomass of chicory and plantain monocultures ... wheat (E Chakwizira) (J Haultain)

Opportunities to improve grazing management (S Biomass accumulation and recovery of dual-purpose 9:25am McCarthy) crops in a dryland environment (J McCormick)

Dry matter intake and body condition score change of The effect of planting date on maize: silage yield and 9:45am dairy cows grazing on fodder beet, kale... (G Edwards) quality, and leaf production (N Morris)

Variation in the reproductive development of perennial The Ballance Agri-Nutrients brassica calculator - im- 10:05am ryegrass cultivars (C Wims) provement of the turnip model (E Chakwizira)

10:25 to MORNING TEA 10:50 am

4: Answers for acid soils: Agronomy Society: Crop Production Systems 2 - 10:50am Chair David Stevens Biofuels, seeds and pests

Medium-term soil pH and exchangeable aluminium Seed potato physiological age and crop establishment 10:55am response to liming at three high country locations (J (D Moot) Moir)

Reduced stem length increased perennial ryegrass seed 11:05am yield (R Chynoweth)

The rise to dominance over two decades of Lupinus 11:15am polyphyllus among pasture mixtures in tussock grassland trials (D Scott)

Cardinal temperatures and vernalisation requirements 11:20am for a selection of vegetables for seed production (J McCormick)

Perennial lupin establishment and yield when sown at Methane production from biofuel crops grown in New 11:35am five different rates at Glenmore Station, Lake Tekapo Zealand (H Kerckhoffs) (D Moot)

Testing of high and low rates of two commercial slug 11:50am baits under high and low simulated rainfall regimes (M Wilson)

Identification and effectiveness of rhizobia strains that

11:55am nodulate Lupinus polyphyllus (T Ryan-Salter)

12:05 - Video Introduction to the Field Trip 12:15 12:35pm Board Buses for Field trip 1:20pm Intensive Land Use: Sponsor Agriseeds

3:00pm Irrigation: Sponsor Farmlands

4:45PM BACK AT VENUE

6:00pm NZGA AGM (Cellar Door) Agronomy Society AGM (Cellar Door)

7:00pm Conference Dinner (and NZGT Awards presentation) at the Cellar Door

Friday 7 November 2014

8:00 Registration - Cellar Door, Centennial Avenue

5a: Improving production with 5b: Improving Hill Country: 8:30 forage. Chair - Derrick Moot Chair - David Chapman

Improving summer and autumn feed quality in New Zealand 8:35 Water use efficiency of fodder beet crops (E hill country (G Rennie) Chakwizira)

Adaptation of Trifolium repens x T. uniflorum hybrid Is nitrogen fertiliser an economic option in tussock hill 8:55 clovers to drought stress (K Widdup) country? (D Stevens)

Effect of timing of harvest on nutritive value of four The economics of transformation toward sustainable hill 9:15 cultivars of kale (Brassica oleracea L. Var. acepha- country land use: Whatawhata case study (M Dodd) la) (C Westwood)

Early performance of oversown pasture mixtures on non- Performance of fodder beet cultivars in the South 9:35 cultivable hill country at four geo-climatically different sites Island (G Milne) (K Tozer)

Deriving pasture growth patterns for Land Use Capability 9:45 Classes in different regions of New Zealand (R Cichota)

9:55 TO MORNING TEA 10:25 AM

10:25 a.m. Levy Oration: Sponsor NZGA: Chair Warwick Lissamann

6a: Hot Topics: 6b: Our Environment: 10:55 a.m. Chair Graham Kerr Chair David Stevens

The chemical composition of high sugar and control The production and water extraction of lucerne and 11:00am ryegrasses in grazed pastures at different latitudes ryegrass under different irrigation frequencies on a shallow throughout NZ (G Cosgrove) soil. (A Michel)

Agronomic assessment of gibberellic acid and cyto- kinin plant growth regulators with nitrogen fertiliser Effects of fertiliser management on nitrate leaching risk 11:20am application for increasing dry matter production and from grazed dairy pastures (I Vogeler) reducing the environmental footprint (A Ghani)

Elevated atmospheric CO2 alters flowering time of Novel approaches to improving growth of pasture legumes 11:40am ryegrass cultivars (B Maw) at low phosphorus levels (S Nichols)

Caucasian clover responses to superphosphate, Potassium requirements of pasture on pumice soils (J Mor- lime and rhizobial inoculant at Lake Heron Station, 12:00pm ton) Canterbury (A Black)

12:20pm Closing session: NZGA President Invites you to Masterton 2015

12:30 CONFERENCE CLOSES

GREENFIELD NZ PASTURES LTD been used for fine wool and store lamb production. In these extensive systems, pasture renovation and Overview capital fertiliser applications have been limited by Greenfield is an internally managed farming company financial constraints and unpredictable returns. To producing predominantly lamb from New Zealand determine the potential economic benefits of inputs freehold farmland. It is an unlisted farming company for development in these regions requires quantifica- operating some 23,500ha of productive New Zealand tion of the benefits gained through the correction of farmland on behalf of its institutional shareholders. soil nutrient status and the introduction of efficient In a typical year we: pasture species. In many cases perennial ryegrass pastures are unreliable and lucerne has been grown  Finish 200,000 - 300,000 lambs as conserved feed. During today’s visit we will exam-  Produce 250 tonnes of wool ine the pasture productivity gains measured on farm  Export 5,000 - 10,000 head of premium live breed- from pasture improvement through capital developing cattle (Dairy and Beef) ment.  Cut 3,953 tonnes of hay, silage and baleage Hills Creek Station  Graze Dairy cows on behalf of dairy farm owners Manager – Hamish Cameron As custodians of a large area of land, Greenfield is Area Manager – Kevin Smith keenly aware that our success is intimately entwined Area – 3,927 hectares with the health and sustainability of our farming op- Dryland (no irrigation) erations. You can read more about our environmental initiatives on the Sustainability Page on our website www.greenfield.co.nz, however some techniques include:  Direct drilling to minimise erosion and carbon loss to the atmosphere  No use of animal antibiotics or growth accelerants  Full traceability for livestock  Minimal application of nitrogen to pasture  Minimal feeding out of grain  100% pasture fed agriculture - no animal housing Over the past 8 years Greenfield has evolved from New Zealand's leading agricultural investment fund manager to a substantial internally-managed agricultural operating company, and we continue to evolve Hills Creek Station is located 10.8km north of Oture- towards becoming an internationally significant agri- hua (Table 1) in Central Otago. It is an amalgamation cultural producer of premium food products. of 3 properties, purchased between June 2007 and March 2008, and ranges in altitude from 440 to 860 metres above sea level, with an average yearly rainfall of 400-500mm (Table 2). Farm Area (ha) Purchased Hills Creek 927 June2007 Dalmalley 933 March 2007 Pennyweight Ridges 2,067 March 2008 Total Area 3,927

Table 1: Site description for Hills Creek Station

Description Hills Creek Station

Location 10.8 km N of Oturehua

Area (ha) 3 927 Since 2007 Greenfield Agribusiness have been developing dryland properties in the Central Otago and Altitude range (m) 440- 860 Strath Taieri regions. Traditionally, the cold winters Soil Types Yellow-Grey and low annual rainfall have meant this region has (Soil Bureau Bulletin No.27) Yellow Brown

Table 2: January, July and annual mean temperature (°C) and rainfall (mm) from selected NIWA Lauder meteorological station for 2000-2010.

Temperature Temperature Rainfall January July Annual NIWA Station Farm max Mean min Rain Max Mean min Rain Mean Rain Lauder Ews Hills 23.3 16.4 9.5 57.5 6.7 1.9 -2.8 22.0 9.7 424.4 Creek

Table 3: Typical soil test results pre- and post-fertiliser applications from Hills Creek Station 2008 and current average test result (Mar 2013).

Hills Creek Date pH Olsen P Ca (QTU) Mg (QTU) K (QTU) S (ug/g) Al (mg/kg) (ug/ml)

Pre Aug ‘08 5.2 10 6 21 5 14 2.6 Post Oct ‘08 5.8 19 7 23 9 31 0.9

Current Mar’13 6.2 20 10 25 12 11

Resident pastures before development commenced were dominated by browntop with lesser contribu- tors from hieracium (Hieracium pilosella L.), sweet vernal, perennial ryegrass and other annual grass species. Legumes were also present which included white and suckling (Trifolium dubium L.) clovers. Hills Creek has different classes of country from flat paddocks through to rolling hills and steeper gullies. Soil tests were conducted before and after pasture renewal (Table 3). Hills Creek Development An intensive development programme on the property included the application of at least 250 kg/ha of superphosphate as capital fertiliser and 3-5 t lime/ha, Application of capital lime on Hills Creek Station 2008 broadcasted on to the resident vegetation. This was followed by an autumn herbicide spray pro- In 50% of the paddocks ‘Grasslands Kaituna’ lucerne gramme (April/May) aimed at controlling the brown- was sown alone at 10 kg/ha (Superstrike treated). top. Application of the equivalent of 6 L/ha of 360 g/L In about 40% of the other paddocks cocksfoot or tall glyphosate, 40 g tribenuron methyl (Granstar), with fescue were also drilled with the lucerne at total caution in relation to the lime applied in the previous rates of 9 kg/ha (2 kg/ha ‘Tekapo’ cocksfoot and 7 kg two months, and 150 ml of an organosilicone pene- /ha lucerne) or 15 kg/ha (7 kg/ha ‘Quantum II’ tall trant. fescue superstrike and 8 kg/ha lucerne). The paddocks were left fallow over the winter, be- Perennial ryegrass (with the AR37 endophyte) was fore a second spray with the equivalent of 4 L/ha also sown into the other 10% of the farm at 25 kg/ha glyphosate, 400 ml/ha of chlorpyrifos insecticide and with 2 kg/ha of cocksfoot and 3 kg/ha of ‘Tahora’ 150 ml/ha of the organosilicone penetrant in the ear- white clover. ly spring (September/October). A second application During development: Whole blocks sprayed out and of tribenuron methyl would be used if required, and left to winter fallow before sowing in the spring. paddocks were then left for 3-14 days before being After sowing, all lucerne paddocks were left to flower drilled. Seed was direct drilled, predominately with a before their first grazing. All ryegrass pastures were triple disc and 100 kg/ha of serpentine super drilled left approximately 6-8 weeks before the first grazing, with the seed. to ensure the seedlings had sufficient root system to avoid pulling damage.

No mechanical harvesting of forage occurred in the Development Spend first year on any paddock. To enable the Greenfield system to increase pasture After the first winter, the pastures were grazed or production to a level which provides an economic mechanically harvested as required. All paddocks return, capital development has been a critical com- were rotationally grazed for 3-10 days on a 35-42 day ponent. rotation, depending on the rate of plant growth. The lucerne/fescue paddocks were grazed on a shorter Key figures Total 15-25 day rotation. Property size (hectares) 3,927 Each lucerne paddock was left to flower every year at some stage after Christmas to build up root reserves Acquisition prices $8,800,000 and thus maximise regrowth the following spring. Redevelopment (June 11) $4,993,000 Nitrogen was only applied to the ryegrass pastures if needed and then at rates of 40 kg N/ha in spring as Total capital employed (June 14) $13,793,000 urea. The lucerne and lucerne/grass pastures did not re- Capital development costs equate to $1,271/ha ceive any nitrogen fertiliser. After the second winter, which is broken down into key components: the lucerne paddocks received a maintenance winter spray (June/July) using paraquat at 2 L/ha with or without 1 kg/ha of atrazine. Soil tests occurred each March, pasture analysis results were taken in the following October then maintenance fertiliser was applied as required.

2010/11 2011/12 2012/13 2013/14

Operating 13.7% 12.0% -3.1% 10.9% Yield

Carrying Capacity Pre Development 2007: Resident Vegetation The carrying capacity of Hills Creek Station has more than doubled, due to the intensive development that has occurred. When the properties were first purchased the carrying capacity was about 4.5 SU/ha, and it is currently sitting at 10 SU/ha.

Post Development 2008: Established Lucerne

Years Lambs Ewes Beef Beef Dairy/ Hay Cows Heifers (Bales)

10/11 83,198 4,869 2,213 527 - 6,400

11/12 108,324 5,544 1,781 675 666 8,456

12/13 83,936 4,193 2,606 225 784 7,046

13/14 66,107 7,470 1,689 232 1,085 1,877

Ave 85,391 5,519 2,072 415 634 5,945

Pasture Production During development: Whole blocks sprayed out and left Table 4. Pasture types and improved areas at Hills Creek dur- to winter fallow before sowing in the spring. ing the 2013/2014 season.

Pasture Type ha Water Use Efficiencies Lucerne established 2299 Lucerne 2 year old 62 The total annual production from lucerne is likely to Pasture dryland 115 be dependent on the amount of rainfall received from when it shuts down growth in the autumn, due Oversown 824 to cool temperatures, until it regrows in the following Crop 43 spring. Unimproved 564 st Waste 20 For example, from the 1 May 2008 (Figure 3) until the 1st September 2008 there was 243 mm of rainfall Total 3,927 ha with little to no pasture growth. Effectively this win- In Central Otago, yields from resident grass based ter fallow provided around 100 mm of stored soil pastures are typically low, so it is critical that Green- moisture (what the soil can hold) to assist spring pas- field adopt species and systems that will convert the ture production when temperatures increased again limited amount of annual rainfall into high quality in September. forage. Additional in-season rainfall (which is the key to total Traditionally, perennial ryegrass has been the most annual yield) then maintained at least some growth commonly sown species, but a lack of dry matter between rainfall events until all of the stored soil (DM) production and persistence have seen its suita- moisture had been utilised. bility in dryland areas questioned. Greenfield has For the unimproved browntop dominant pasture, adopted a lucerne based system, as it has a competi- growth essentially stopped in January (Figure 2). The tive advantage in dryland environments to produce improved pastures and lucerne growth continued high quality forage through the growing season. into March but the rate of growth for lucerne was almost double that achieved by the ryegrass based Table 5. Pasture yield (kgDM/ha) and rainfall (mm) over six pastures. years from three different pasture types grown on Hills Creek Similarly in 2009/2010 the unimproved pasture growth Lucerne Dryland Unimp Rainfall stopped in January. However, in this season the lack of Year established pasture pasture mm winter and in-season rainfall meant the lucerne and 08/09 7,600 2,800 1,400 668 improved pastures also ceased growth at this time. st st 09/10 4,400 3,100 1,100 496 From 1 May until the 1 September 2009, there was 10/11 6,900 4,200 1,400 700 only 141 mm of rainfall which produced only 45-55 mm of available soil moisture at the 1st September. A 11/12 7,700 4,000 1,100 647 further 136 mm of rain was recorded to the 1st Janu- 12/13 7,200 4,300 1,300 683 ary. 13/14 5,900 4,500 1,600 471

In a recent publication (Kearney et al. 2010) it was suggested that at Hills Creek, the lucerne accumulated 4 times more drymatter compared with the unimproved areas and that during the spring period, the lucerne converted rainfall (RE) to drymatter at a rate of 52gDM/ha/mm compared with the resident unimproved pastures at a rate of 10kgDM/ha/mm.

Figure 1. Daily pasture growth rate (kgDM/ha/day) for lucerne at Hills Creek for 2011/2012, 2012/2013 and 2013/2014

Figure 2. Annual accumulated pasture growth and weekly rainfall for the period July 2008- May 2010 at Hills Creek farm, Central Otago.

Figure 3. Potential soil moisture deficits (SMD) for the period May 2008- May 2010.

The importance of winter rainfall and subsequently low temperatures, transpiration also stops so soil mois- spring growth can be quantified by calculating the WUE ture recharge occurs. during this period. The NIWA soil moisture deficit (SMD) data allows for the For example, at Hills Creek, when stored soil water from potential evapotranspiration over winter where there is winter was not included in the crop water use a rainfall still significant evaporation from bare soil so that not all efficiency (RE) of 53 kg DM/mm was calculated for lu- winter rain becomes stored soil moisture. The level of cerne and 11.4 kg DM/mm for the unimproved pasture. this recharge is then dependent on the water holding In both cases the rainfall efficiency over estimates the capacity of the soil before field capacity is reached and WUE because it does not account for the use of the drainage occurs (Moot et al. 2008). stored soil moisture. An estimate of the amount of soil water used can be References made from the change in soil moisture deficit recorded www.greenfield.co.nz at the nearest NIWA met station. For Hills Creek, using Ranfurly data (NIWA), the soil moisture deficit in spring Kearney, JK.; Moot, DL.; Pollock, K. 2010. Comparison of 2008 increased from 26 to 145 mm. This contributed pasture production in relation to rainfall and tempera- about 120 mm of water in addition to the rainfall that ture data measured on farm in Central Otago. Proceed- fell in spring. ings of the New Zealand Grassland Association 72: 121- 126. Using these values, the WUE of the lucerne was calculated to be 17 kg DM/ha/mm, which is comparable with Moot, D.J.; Brown, H.E.; Pollock, K. and Mills, A. 2008. other reports for lucerne (Moot et al. 2008). Yield and water use of temperate pastures in summer dry environments. Proceedings of the New Zealand The WUE was 3.7 kg DM/ha/mm for the unimproved Grassland Association 70: 51-58. pasture. The difference in winter soil water storage is highlighted by the change in soil moisture deficit in 2009. This was only 45 mm, which combined with only Thanks to J Kearney for preparing handout material. 90 mm of spring rainfall, left the resultant WUE un- changed. However, the NIWA data on soil moisture can only approximate the actual soil moisture on any given paddock because of different soil depths, pasture rooting depth, and differences in rainfall and potential evaporation between sites. Calculating on farm water use efficiency (WUE) To calculate on farm WUE relies on accurate rainfall data and preferably a close estimate of the contribu- tion of stored soil water by using nearby NIWA climate station data. The process is to then add a percentage of winter rainfall to the following growing season rainfall or use an on farm measurement of soil moisture status. Once pasture growth stops in autumn/winter, due to

IDA VALLEY STATION on the valley floor in areas where a high water table sustains growth through summer. Lucerne is now ex- Ida Valley Station was purchased by John Paterson in tending into the foothills where it provides a resilient 1964 with two further blocks, Dovedale and Man- high quality forage for lamb and fawn finishing. orside (together referred to as Dovedale) purchased These developments have offset declining hill country in 1993. Today Callum and Dougal Paterson operate production but have substituted relatively cheap pas- the farm in partnership running 26,800 stock units ture for more expensive forages. Unless the decline is within sheep, deer and cattle enterprises. Both Ida hill country can be arrested this flow of capital into Valley and Dovedale start at an altitude of 412m asl intensively managed forages will continue without a with a rainfall of 303mm at the valley floor gradually net gain to the business. rising with altitude to perhaps 450mm at the highest In 2013 a project was sponsored by the New Zealand points (1040m). Merino Company to assess the strategic direction for Historically, growing the business has been achieved growing businesses such as Ida Valley. This analysis through oversowing, topdressing and subdivision of has important implications for properties with declin- hill country. The rolling contour, dry climate and ing hill country productivity. This paper summarises abundant schist tors provide good shelter and aspect the strategic analysis. for lamb and fawn survival providing a simple system with high livestock performances. Methodology Today the business is dominated by two important The first step in the strategic analysis was to develop factors: a base model of the farm that reflected how feed 1) Climate - both the hot dry summers and cold win- supply meets the feed demand of livestock using the ters and prolonged drought computer modelling tool Farmax (Marshall et al, 2) Declining production from oversown and top- 1991). dressed hills. Livestock enterprises were constructed based on the Over the past four decades approximately 750,000 ha last 3 years statistics for stock numbers and perfor- of extensively grazed landforms in the semi-arid high mance. There is little information on the pasture pro- country have ubiquitously lost plant biodiversity and duction of oversown and topdressed hill country. The stocking rate has declined. approach taken was to set up those landforms for which there is adequate science data (Radcliffe and Dry years and rabbit plagues (particularly in the mid- Cossens, Kearney et al 2010); this included pasture, late 1980’s) have seen increasingly levels of Hieraci- lucerne and irrigation. um pilosilla, danthonia, browntop (Agrostis capil- laris), Poa pratensis and bare ground. This is a shift to To ascertain the likely pasture growth from oversown plants well adapted to storing reserves below ground and topdressed hill country pasture growth profiles and surviving dry spells and overgrazing. Lost have were then applied until the model was feasible. The been clovers, cocksfoot, sweet vernal and native blue feasibility test in Farmax is met when the model is in tussock. equilibrium and the pasture cover on each day is adequate to meet the minimum pasture covers required Simple management systems based on long periods to meet livestock demand. Based on this approach the model estimated pasture production on oversown hill country would be 1.3 tDM/ha/year. Due to the profile of pasture supply less than 50% of hill country pasture growth was pre- dicted to be utilised by livestock. Even at this low productivity and utilisation oversown and topdressed hill country remains the ‘breadbasket’ of the business providing 63% of total dry matter.

Table 1: Main land class descriptions

Area tDM/ha/yr of set-stocking may have played a part in selectively Irrigation (Pivot, KLine, B/dyke) 325 9 - 14 overgrazing favourable plants. Lucerne (Paddocks and foothills) 563 5.8 - 7.0 To build resilience a 34ha dam was established in Paddocks in Grass 346 3.8 2007 providing 180ha of spray irrigation adding to an Oversown and topdressed hills 11404 1.3 existing area of borderdykes. Lucerne is established Total/Average 12638 1.9

Fig 1: Percentage of total forage from 4 main Livestock land classes Fine wool sheep make up the majority of livestock. A deer breeding and finishing herd make up the next largest enterprise with a beef herd and dairy grazers making up two smaller enterprises.

Stock class % Demand Sheep 77 Deer 13 Cattle 7

Dairy Grazers 3

The Base farm - Fertiliser and typical soil tests Sheep The Patersons consider fertiliser essential for sustaina- Polwarth sheep are run in two separate enterprises; a ble management of hill country and a 3 year rotation Polwarth flock run on Ida Valley and a Polwarth flock put of 125kg of Maxi Sulphur Super (0-5.1-0-47) is ad- to a terminal ram is run on Dovedale. hered to. Ida Valley, being owned by the Patersons Polwarth main flock – 8750 ewes with all 8900 lambs are since 1964 has received more regular fertiliser and as kept through winter. 3200 ewe lambs are retained for re- a consequence has higher phosphate and sulphur lev- placements of which 750 provide replacements to a Pol- els. warth terminal flock. All surplus ewe and wether lambs On the Ida Valley block: are sold to the works from October to December. This  The increasing acidity with altitude results in flock achieves excellent reproductive performance and high aluminium levels; hogget finishing growth rates.  Low altitude areas had good pH and generally adequate levels of phosphate. Reproduction– MA Ewes  Mid altitude areas had moderate pH levels are MA Ewe mating weight (kg) 58.0 high in phosphate and low in sulphur;  High altitude areas were low pH and phosphate MA Ewe scanning % 145 but maintain moderate levels of sulphur. Lamb losses (scanning to weaning)% 24 On Dovedale:  Increasing soil acidity with altitude has only a Weaning % 110 slight increase in aluminium levels; Lamb weaning weight (kg) 30.0  Low and mid altitude areas have high soil pH 215 moderate soil phosphate and low sulphur; Lamb growth rate to weaning (Grams/day)  High altitude areas are low in phosphate and Days to weaning (from mean lambing) 119 sulphur with moderate sulphur. Table 2: Typical soil test levels; Ida Valley Station

Ida Valley pH Olsen Mg K Na SO4 Org S Al P S Lower 6.1 19 43 27 2 4 4 1.1 Mid 5.6 24 28 11 2 5 2 2.4 High 4.9 8 26 9 2 13 5 12.4 Dovedale

Lower 6.2 11 38 20 2 3 1 <0.5 Mid 5.5 13 26 7 8 3 1 2.8 High 5.0 8 20 11 2 8 3 11.1

Hogget finishing growth rates g/day Cattle Growth rate winter (May to Sept) 0 The cattle enterprise comprises 230 cows (including Growth rate Sept 15 in calf heifers). Calf sales are highly flexible depend- Growth rate Oct to Dec 200 ing on seasonal conditions. In some years weaner Sales Number Weight (kg) calves are sold store and in others a proportion are taken through to slaughter. Sales Oct 3000 19.5 Dairy grazers Sales Nov 1800 19.2 st Sales Dec 1380 17.7 500 Dairy cows are brought on the 1 of June and transferred off on the 19th of August. During this Total/Average 6180 19.0 time they gain 0.8 kg of liveweight per day and con- sume 11.5kg DM/head. Terminal Polwarth ewes – 4400 ewes bred from ‘off type’ ewe hoggets are put to a terminal ram with all Grazing management lambs finished from January through to April. This From shearing in late July ewes are grazed on flock achieves excellent reproductive performance, ryecorn. Twin ewes from the Polwarth main flock on particularly lamb weaning weights. Ida Valley graze on ryecorn for 1 month while singles Reproduction– MA Ewes ewes and all Terminal Polwarth ewes on Dovedale graze ryecorn for 2 weeks. After grazing ryecorn MA Ewe mating weight (kg) 58.0 ewes are set-stocked on lambing blocks where they MA Ewe scanning % 145 stay until weaning in early February. Lamb losses (scanning to weaning)% 20 From weaning ewes are grazed on summer country Weaning % 116 until June then are brought down to follow lambs through spelled lambing blocks. After they have Lamb weaning weight (kg) 32.0 cleaned these up they are supplemented with silage Lamb growth rate to weaning (g/day) 230 on lower hills until shearing. Days to weaning (from mean lambing) From weaning all terminal lambs are finished on the 118 pivot. Fine wool lambs are rotated on lucerne then ryecorn until June. They are then spread out on Lamb finishing performance growth g/day spelled lambing blocks until late July after which they rate are supplemented with silage. They then graze Growth rate weaning to slaughter 200 ryecorn as it comes away in late winter until lucerne Sales No. Weigh is ready. They are rotated on lucerne and progressively sold from October to December. Sales January 1400 17.5 Sales February 1000 17.0 Replacement hoggets continue to graze lucerne, Sales March 1400 18.2 then spend 6 weeks on Dovedale’s summer country Sales April 1160 16.7 before tupping at which time they are split into the Total/Average 4960 Terminal Polwarth and Polwarth main flock enter- 17.4 prises. Hinds are fawned on hill blocks then after weaning in Deer breeding and finishing enterprise early March are wintered on lower hill country and The deer herd comprises 975 breeding hinds fed silage. All weaners are run on irrigated grass and (including two year in-calf hinds) with approximately lucerne. They are wintered on crop then return to half red deer and half red/wapiti cross deer. Half the irrigated grass and lucerne to be finished. herd is mated to a terminal sire while the other half is mated to a red stag.

Reproduction– MA Hinds

Pregnancy % 92 Losses Pregnancy to weaning % 10

Weaning % 83 Weaning weight (kg) 60

Growth rate to weaning 448 Days to weaning (from mean calving) 111

Key themes for strategic direction Given the key issues of periodic drought and declin- 3. Increasing grazing intervals on hill country – Shift- ing hill country production strategies have been de- ing from prolonged selective grazing of clovers and veloped around 3 key themes: palatable grasses to a rotation that enables greater plant recovery. 1. Improving water use efficiency:  Converting borderdyke and wild flood to spray irri- Strategic options gation- irrigating more area and producing Converting borderdyke and flood irrigation to spray irrigation more from each hectare; Currently there are 145ha of borderdyke and wild  Expanding lucerne - Lucerne is the most effi- flood irrigation. Replacing these areas with spray irri- cient forage plant in converting soil moisture gation would: into dry matter.  Enable an increase in pasture production 2. Fitting livestock feed demand to feed supply – (9.5tDM to 14tDM/ha/year). When livestock feed demand does not fit supply utili-  Free up water to irrigate a further 125ha of sation is low, costs are incurred in shifting supply and dryland currently producing 3.8tDM/ha/year. both pasture covers and grazing residuals are subop-  Deer are currently finished on the borderdyke timal for maximum pasture growth rates. area. Converting to spray creates problems The majority of pasture production occurs in October with deer fencing on this area . to mid-December. From early December through un- However, replacing deer with Terminal Polwarth til late February pasture growth is highly variable. ewes has two benefits - Terminal Polwarth’s feed Ideally, livestock systems utilised a high proportion of demand has the best fit with feed supply; Terminal the reliable growth and are flexible during variable Polwarth’s return per kgDM consumed is the highest summer months. of all enterprises. The monthly demand from each enterprise is shown This option involves selling the deer enterprise and in the figure below relative to pasture production. replacing with 2885 additional Terminal Polwarth The fit between supply and demand and the revenue ewes and 360 dairy heifer grazers. Because the Pol- earning capacities of each enterprise are shown in warth Main flock cannot supply enough ewe hoggets the table below. This supports selling the deer enter- to a larger Terminal Polwarth flock 500 ewe lamb prise and keeping cattle numbers low. replacements are purchased. The likely cost to develop irrigation is $10,000/ha but Enterprise Fit with peak Flexibility Revenue selling the deer enterprise frees up $326,975. At total growth capital cost of $2,173,000. Terminal ewes High High 18.2 Polwarths High Moderate 16.6

Cattle Low Moderate 10.1

Deer Low Low 13.8

Terminals Current Irrigation Difference Value Stock Units

MA Ewes 3650 6045 2395 227525 2395

2th Ewes 750 1240 490 59290 490

Total Ewes 4400 7285 2885 286815 2885

Deer

MA Hinds 800 0 -800 -368000 -1520

2 Year Hinds 174 0 -174 -67860 -313

Total Hinds 974 0 -974 -435860 -1833 1 Year Hinds 378 0 -378 -75600 -454

1 Year Stags 379 0 -379 -102330 -531

Total 1 Year Deer 757 0 -757 -177930 -984

Total Deer -613790 -2817

Dairy 0 360 360 0 820

Total value change -326975 888

Changes to costs Once irrigation is fully established the cost increases associated are: Labour $15,000 Animal Health $4,600 Shearing $31,700 Fertiliser $17,100 Electricity for irrigation $10,000 Repairs and maintenance $5,000 Depreciation $100,000

Sheep grazing lucerne Developing lucerne

Ida Valley has 910ha that can potentially be devel- Table 3: pH and Al levels measured at different oped into lucerne. Lucerne’s strengths are its deep depths (cm) in soil profile rooting and nitrogen fixation. pH 0-7.5 7.5-15.0 15.0- 35.0- 55.0- In this environment there are potentially soil alumini- 35.0 55.0 75.0 um and soil acidity issues. While liming can control Moa Creek 5.2 5.4 5.8 5.7 5.9 these issues in the top 7cm, unfavourable levels may exist below this. Soil tests were undertaken on the 3 Patersons 5.8 5.6 6.1 6.5 6.6 sites considered for establishing lucerne. Barretts 5.3 5.5 6.3 6.3 6.4 Two sites, Moa Creek and Barretts have low pH at the surface with moderate/low aluminium (below 3). Al 0-7.5 7.5-15.0 15.0- 35.0- 55.0- Tests taken through the soil profile show pH increases 35.0 55.0 75.0 with depth. Moa Creek takes longer to increase but at Moa Creek 2.9 2.6 2.4 1.6 1.1 55cm has a pH of 5.9. As soil pH increases aluminium Patersons 0.7 0.6 <0.5 <0.5 <0.5 drops rapidly on Patersons and Barretts. Moa Creek is Barretts 2.0 1.1 <0.5 <0.5 a more acidic site <0.5

19 and aluminium declines more slowly. However levels This analysis has used an annual lucerne production do not exceed 3.0 and by 55cm soil pH and low alu- of 5.8 tDM/ha/year. This extra feed is used to in- minium are favourable for lucerne to thrive. crease per head performance and increase sheep Developing 910ha of lucerne creates extra feed for numbers. The performance figures outlined below the Polwarth main flock through: are when the flock is in equilibrium. Better lamb performance has led to higher 2th Ewes tupping weights  Ryecorn crops used in the pasture renewal pro- and therefore increased 2th Ewe weaning %. As 2th cess available in March to May and August to Ewe replacements enter the flock at higher weights October; the average weight of ewes has increased by 4.5kg.  Through high quality Lucerne during lactation to increase lamb growth rates.

Reproduction– MA Ewes Current Lucerne Higher weaning weights and post weaning growth rates enable 48% MA Ewe wool production (kg clean) 3.8 4.0 (2400) of lambs to be sold in May MA Ewe mating weight (kg) 58.0 62.5 after shearing to the works. MA Ewe scanning % 145 156 Developing lucerne will decrease Lamb losses (scanning to weaning)% 24 21 stocking rate on hill country:

Weaning % 110 122 During lactation - At a stocking rate on lucerne of 6 ewes/ha during lac- Lamb weaning weight (kg) 30.0 35.0 tation 5460 ewes (of the 8750 total) Lamb growth rate to weaning (Grams/day) 215 255 are run from lambing to weaning on Days to weaning (from mean lambing) 119 lucerne rather than OSTD blocks. This provides significant spelling of a Reproduction– 2th Ewes Current Lucerne large proportion of the Ida Valley 2th Ewe wool production (kg clean) 3.8 4.0 hill country during its growing 2th Ewe mating weight (kg) 49.0 54.0 phase. This would allow these areas to gain cover from mid-October and 2th Ewe scanning % 112 124 then be available for ewes post Lamb losses (scanning to weaning)% 20 18 weaning. Weaning % 90 101 Autumn and spring - The feeding of Lamb weaning weight (kg) 28.0 32 ryecorn in March to May and Au- gust to October would also provide Lamb growth rate to weaning (Grams/day) 200 232 benefits to staying off OSTD blocks Days to weaning (from mean lambing) 119 (allowing autumn growth to be car- Replacement rearing Current Lucerne ried forward) until lambing.

Hogget wool production (kg clean) 2.20 2.35

1st May weight (kg) 32.5 37.1

Growth rate weaning to May (Grams/day) 75 83

th Shearing weight (15 September) kg 34.0 38.8

2th Ewe mating weight (kg) 49.0 54.0

Hogget finishing performance Current Lucerne Growth rate winter (May to August) 0 0 Growth rate September 15 15 Growth rate October to December 200 200 Sales Current Lucerne Number Carcass (kg) Number Carcass (kg) Sales May 0 2407 20.9 Sales October 3000 19.5 3000 19.0 Sales November 1800 19.2 1860 18.5 Sales December 1380 17.7 Total/Average 6180 19.0 4980 19.3

Modelling calculates ewe numbers can be increased by 3750.

Polwarths Current Lucerne Difference Value Stock Units MA Ewes 6300 9200 2900 275500 2900 2th Ewes 2450 3300 850 102850 850 Total Ewes 8750 12500 3750 378350 3750 Ewe hoggets 4640 7350 2710 211380 1897 Wether hoggets 4640 3906 -734 -50646 -513.8 Total Hoggets 9280 11256 1976 160734 1383.2 Total value change 539084 5133.2

Changes to costs Changes in the cost structure include: One more labour unit $45,000 Increases in animal health and shearing 100 ha of Lucerne is taken out each year and goes through two years of ryecorn $176,000/annum Lucerne re-establishment $60,000 Extra fertiliser $45,000 Associated increases in repairs and maintenance.

Developing both irrigation and lucerne There are three significant advantages with developing This option combines both the irrigation development both options together. and the lucerne development above. It involves the following changes: Because the Polwarth main flock has more breeding  The Polwarth main flock performance and num- ewes there is no requirement to buy extra replacement bers are increased as outlined in the Lucerne op- hoggets for the expanded Terminal Polwarth flock (as tion. This utilises all the extra feed produced from outlined in the irrigation option). added lucerne; The Terminal replacement hoggets from the Polwarth  Removal of the deer enterprise and substitution main flock are raised to a heavier tupping weight in the with more Terminal Polwarths as outlined for the lucerne system. This leads to a higher Terminal Polwarth irrigation option; ewe liveweight and therefore a higher lambing percentage and wool weight.  No dairy heifer grazers. Instead Terminal Polwarth numbers are increased. The extra Terminal lambs can be finished at higher growth rates on irrigation and lucerne.

Terminal Polwarths Current Lucerne Difference Value Stock units

MA Ewes 3650 6900 3250 308750 3250

2th Ewes 750 1400 650 78650 650

Total Terminals 4400 8300 3900 387400 3900 Polwarth Main Flock

MA Ewes 6300 9200 2900 275500 2900

2th Ewes 2450 3300 850 102850 850 Total ewes 8750 12500 3750 378350 3750 Ewe hoggets 4640 7535 2895 225810 2027

Wether hoggets 4640 4000 -640 -44160 -448

Total hoggets 9280 11535 2255 181650 1579 Total Polwarths 560000 5329

Deer

MA Hinds 800 0 -800 -368000 -1520 2 Year Hinds 174 0 -174 -67860 -313

Total Hinds 974 0 -974 -435860 -1833

1 Year Hinds 378 0 -378 -75600 -454 1 Year Stags 379 0 -379 -102330 -531 Total 1 Year Deer 757 0 -757 -177930 -984 Total Deer -613790 -2817 Dairy 0 290 290 0 375 Total value change 333610 6411

The higher performance from the Terminal mob is shown below:

Reproduction MA Ewes 2th Ewes Current Lucerne/ Current Lucerne/ Irrigation Irrigation MA Ewe wool production (kg clean) 3.8 4.0 3.8 4.0

MA Ewe mating weight (kg) 58.0 63.0 49.3 54.0

MA Ewe scanning % 145 153 116 128

Lamb losses (scanning to weaning)% 20 20 18 18

Weaning % 116 123 96 105

Lamb weaning weight (kg) 32.0 33.5 29.0 30.5

Lamb growth rate to weaning (Grams/day) 230 245 210 222

Days to weaning (from mean lambing) 118 118

Lamb finishing performance Current Lucerne/Irrigation Growth rate weaning to slaughter 200 200 Sales Current Lucerne/Irrigation Number Carcass (kg) Number Carcass (kg) Sales January 1400 17.5 1400 19.2 Sales February 1000 17.0 1000 19.0 Sales March 1400 18.2 2900 19.6 Sales April 1160 16.7 3410 18.9 Total/Average 4960 17.4 8710 19.2

Changes to costs

Changes in cost structures include: Two more labour units $80,000; Increases in animal health and shearing associated with stock increases; 100 ha of Lucerne is taken out each year and goes through two years of ryecorn $176,000 Regrassing (est Lucerne) $60,000 Extra fertiliser $62,100 Increased vehicle expenses $20,000 Associated increases in repairs and maintenance.

Increasing intensity of hill country graz- would grow an extra 200kg of pasture dry matter ing management annually, increasing annual production from 1.3 This option scopes the value of not only arresting hill tDM/ha/year to 1.5 tDM/ha/year. country decline but modestly improving pasture pro- This increase in annual production enables an in- duction. Ida Valley has rigidly applied fertiliser and crease of 2850 breeding ewes. The only associated low and mid-altitude landforms are now in optimal costs are labour, animal health and shearing. macronutrient ranges. The loss in biodiversity is un- Results and discussion likely to be the result of soil fertility. It is more likely Financial the result of: All options have a moderate to high return on invest-  historical events such as rabbit plagues and ment and are worth pursuing. Irrigation, while a ro- drought; bust technology providing resilience in years of  the invasive nature of Hieracium when condi- drought, has the highest investment cost per dollar tions are favourable; of added revenue and a high depreciation cost. The  long periods of set stocking. result is an 11.8% return on investment. There is very little science undertaken to show the Dryland options offer the greatest return on invest- benefits of significantly increasing subdivision. It is ment. They are relatively cheap to develop with: likely the degree of subdivision needed to radically  The lucerne system achieving high perfor- change the grazing rotation is much greater than mance from quality forage grazed during ewe high country farmers would envisage. lactation and hogget finishing. The result is a In this option we simply allow for enough subdivision 20.6% return on investment; and water supply to divided current blocks using  Improved hill country production providing a electric fencing into 3 times the number of paddocks low cost method of providing average quality (150ha paddocks become 50ha). We also employ feed to simply run more sheep. The result is a two extra labour units to carry out the greater level 21% return on investment. of stock management. The total cost of fencing and water is approximately $1million. We assume we

Profit and Loss Base Irrigation Lucerne Lucerne & Hills Irrigation +200kgDM Farm Income Net Sheep Sales 1,307,200 1,567,700 1,909,900 2,470,000 1,551,000 Net Wool Sales 925,900 1,080,500 1,281,800 1,471,000 1,064,870 Net Beef Sales 116,300 116,300 116,300 116,300 116,306 Net Deer Sales (Including velvet) 268,500 268,500 0 268,500 Dairy Grazers 158,000 457,200 158,000 158,000 158,000 Total Farm Income 2,775,900 3,221,700 3,734,500 4,215,300 3,158,676 Farm working expenses Wages 160,000 175,000 205,000 240,000 240,000 Animal Health 122,600 127,200 156,000 175,100 138,300 Shearing 204,700 236,400 279,000 316,180 232,000 Stud expenses 15,000 15,000 15,000 15,000 15,000 Breeding expenses Feeds - Conservation 120,800 120,800 120,800 120,800 120,800 - Less homemade allowance -35,000 -35,000 -35,000 -35,000 -35,000 - Forage crops 75,000 75,000 251,000 251,000 75,000 Regrassing 30,000 30,000 90,000 90,000 30,000 Irrigation 17,500 17,500 17,500 17,500 17,500 Fertiliser 260,000 260,000 260,000 260,000 260,000 -New Fertiliser 17,100 45,000 62,100 Weed and pest 55,000 55,000 55,000 55,000 55,000 Vehicles 125,000 130,000 135,000 145,000 125,000 R&M Land and buildings - Buildings 50,000 50,000 50,000 50,000 50,000 - Fences 50,000 50,000 53,000 58,000 50,000 - Water supply 25,000 30,000 25,000 30,000 25,000 - Stock water 5,000 5,000 7,000 9,000 5,000 - Tracks 20,000 20,000 20,000 20,000 20,000 Freight 35,000 35,000 35,000 41,000 35,000 Electricity 50,000 60,000 50,000 60,000 50,000 Sundry 45,000 45,000 45,000 45,000 45,000 Administration 40,000 40,000 40,000 40,000 40,000 Insurance 37,500 37,500 37,500 37,500 37,500 Rates 18,500 18,500 18,500 18,500 18,500 Total Farm Working Expenses 1,526,600 1,615,000 1,975,300 2,121,680 1,649,600

EBITDA 1,249,300 1,606,700 1,759,200 2,093,620 1,509,076 Management wage 150,000 150,000 150,000 150,000 150,000 Depreciation 120,000 220,000 145,000 220,000 170,000 Economic Farm Surplus 979,300 1,236,700 1,464,200 1,723,620 1.189,076 Marginal return 257,400 484,900 744,320 209,776 Capital Investment 2,173,000 2,359,000 4,153,600 1,000,000 Return on investment (%) 11.8 20.6 17.9 21.0 $ Expenditure/kg of extra revenue 8.44 4.63 4.92 3.85

Conclusions

The analysis highlights the complexities of developing strategic plans for properties with diverse landforms and livestock enterprises. Modelling of the base enterprise is helpful in understanding how the farm system must be re-designed for each option. Investing in irrigation

This has a high capital cost and a moderate return on investment. It involves:  Selling the deer enterprise and as a result capital is freed up for investment.  Deer are substituted with Terminal Polwarths and dairy heifer grazers that earn more per kg of dry

matter consumed and have a better fit with feed supply. Developing high quality dryland forage using lucerne More intensively manage oversown and top- The modest cost of investment and the improvement in dressed hill country ewe’s lactation performance result in a high return on This option is clearly a theoretical analysis. The intensity investment. This option has the added value of: of subdivision, the grassland’s response to intensive  Allowing some hill country to be spelled during management and the time it would take to achieve this late spring/summer; response are all unknown. There is however some anec-  Ryecorn crops grown in the regrassing phase add dotal evidence (Anderson et al, 2014). This analysis valuable winter feed; shows a high return on investment if the goals of this strategy are achieved. The key benefits are:  Enabling some Polwarth lambs to be finished before winter reducing overall winter demand;  it changes the direction from grassland decline to grassland recovery;  The rate of development can be set to allow management to ‘learn by doing’.  inputs are simply fencing, water and labour;  Developing irrigation and lucerne together the return on investment does not require greater per head performance or changes in the livestock This has significant synergies and as a result the return policies. on investment is closer to dryland options. Synergies in- While this has not been specifically modelled a more include: tensively manage oversown and topdressed hill country The irrigation can be stocked entirely with high quality is likely to achieve the highest return when combined stock raised in the lucerne system. with lucerne development. This option has a significant effect of the overall pasture  It would enable smaller age-scanned lambing supply profile. The charts below show that the feed pro- mobs to be progressively lambed on the hill then vided from irrigation and lucerne would increase from transferred to lucerne; 31% to 50%. Without specifically modelling these affects  Smaller blocks could be grazed in conjunction with is can be assumed the Lucerne - irrigation option would feeding off lucerne in summer and ryecorn in win- reduce year to year variability. ter.

The value of this modest increase in hill country produc-

tivity across the approximately 750,000ha of land facing issues of decline is significant. Based on this analysis for every increment of 200kg of dry matter per hectare in grassland productivity is estimated to be worth $25 million to the New Zealand economy and $14 million to farmers annually. The lack of science input into the issues of hill country decline needs addressing as the cost of the ‘do nothing’ scenario is too great.

Soil test plan

Thanks to G Ogle for preparing handout material. Acknowledgements The New Zealand Merino Company sponsored this project through the Primary Growth Partnership. Ravensdown Fertiliser funded and carried out soil testing on 23 sites on Ida Valley and Dovedale. References Anderson D., Anderson L., Moot D.J. and Ogle G.I. 2014 Integrating lucerne (Medicago sativaL.) into a high country merino system. Proceedings of the New Zealand Grassland Association 76. This conference. Kearney K.K., Moot D.J., and Pollock K.M. 2010. On-farm comparison of pasture production in relation to rainfall in Central Otago. Proceedings of the New Zealand Grassland Association 72: 121-126. Marshall P.R., McCall, D.G. and Johns, K.L. 1991. Stockpol: A decision support model for livestock farms. Proceed- ings of the New Zealand Grassland Association 53: 137-140. Radcliff J.E. and Cossens G.G. 1974. Seasonal distribution of pasture production in New Zealand III. Central Otago. New Zealand Journal of Experimental Agriculture Vol 2: 349-358.

AERIAL OVERSOWN AND TOPDRESSED scenarios : HILL COUNTRY  Introduced legumes such as red and white clover have declined in vigour. TIME FOR REVISION  Introduced species such as red clover, white clover A farmers perspective presented by Denis Fastier and alsike have failed to survive. History  Introduced species such as red and white clover have been replaced with lower producing legumes When I first started farming 40 years ago the High Coun- such as suckling clover, striated clover, and hares- try mantra was aerial oversow and topdress foot clover. (oversowing). Why would you cultivate and drill lucerne, Possible reasons for the decline of legumes: creating a high cost and high maintenance system, when you could aerial oversow and topdress and create one of  Rhizomatous grasses have benefitted from the ni- low cost and low maintenance? trogen produced by the introduced clovers, to such an extent, that they are competing with and That mantra was right for that time. in some cases smothering out the introduced clo- Oversown and topdressed country became the back- vers. bone of the high country production system. The income  The ingress of hieracium, both pilosella and prae- generated from oversowing allowed farmers to : altum  Construct access tracks  The decline in soil pH  Build subdivision fences and infrastructure  The increase in aluminium levels in the soils  Control weed and pests  Overgrazing by sheep and rabbits  Irrigate  Preferential grazing of legumes by sheep  Develop down land paddocks for lucerne and win-  Undergrazing by sheep and cattle. ter feed production.  Purchase more land to create a better balance, or Opportunities to add scale. Pushing the boundaries for Lucerne establishment. Current State Traditionally lucerne has been established on flat and rolling country for winter feed production and The production system that evolved from oversowing is some fin- being challenged on many fronts. ishing.  Production from oversowing is declining. Dave Anderson from Bogroy has pioneered a way of seeking out niche areas within this traditionally over-  Higher country has been surrendered under ten- sown hill country and establishing lucerne. The method ure review with the subsequent loss of summer of establishing and managing lucerne in this environ- grazing for ewes, or loss of wether grazing. ment has been very well covered by Dave (see paper this  Irrigation requires further investment to achieve Proceedings). better irrigation efficiency and nutrient manage- Some may argue that that the area of the High Country ment requirements. that can be developed in this way is a small percentage  The need for scale is relentless and ongoing. of the total area, which is true, but the total production  Age of farmers, and the difficulty of achieving farm is still very significant. succession in an environment where future pro- I want to postulate that not only is the total production duction is being challenged. significant, but the off site benefits to oversown hill Focus country may also be significant. The focus of my comments is to look at the issue of de- The traditional grazing model of rotating ewes and lambs clining production from oversowing hill country. around oversown hill country until weaning meant that by the time blocks were spelled soil moisture had been This decline in production has in general been gradual, exhausted, and there was little chance of plant recovery, and appears to have depended on: often until late autumn, when it was required again for  Altitude grazing.  Aspect If we remove lambs from oversown country immediately  Rainfall post lambing and graze them on lucerne then this coun-  Soil type try can be spelled when there is a high chance of suffi-  Grazing management cient moisture being available for it to flower, set seed,  Pest control and build root reserves. A common thread seems to be the decline in the legume A model management scenario could look like this. In a production from this country. Observation of legume wetter than average year most of the ewes and lambs production in different environments offer the following could be mustered off the oversowncountry, post

27 lambing, and managed intensively on the lucerne. The of a variety of legumes but grasses reinvaded sug- traditional model in a wetter than average year was to gesting a further fallow or break crop was re- push all the ewes and lambs onto the hill, and then cut quired. the lucerne for additional winter feed or for sale. It was  Dense rhizomatous swards tend to occur on deep- often difficult to make quality hay in a season like this, er soils, often dark sides, that lend themselves to the market was flooded with everyone else looking for a more intensive subdivision, and very high stocking similar opportunity, and additional storage was not avail- rates can be used to control grass and encourage able. Older farmers used to say that “hay in the barn was any existing clover. as good as money in the bank”, but maybe the newer  Steeper country had less dense sward and provid- generation should say that “a seed set on the hill is ed more opportunity for introduced legumes. better than extra hay in the barn”.  Some legumes could outperform hieracium on In an average rainfall season say 30% or 50% of the deeper soils or higher rainfall. sheep are mustered off the oversown hill country, post  Legumes that established in triple sprayed ground lambing, and intensively managed on lucerne. This way and showed promise were : lucerne, red clover, blocks could be spelled every second or third year. white clover, russell lupins, caucasian clover, bal- In a drier than average season sheep may be mustered ansa annual clover, lotus corniculatus, and maku off the oversown country to be managed on lucerne, but lotus. have to be returned before weaning when the lucerne There needs to be ongoing work to establish the soil pH has run out of moisture. We may not have achieved a range, and rainfall gradient best suited to each of these flower and seed set but we still have a bank of feed to species. Their survival needs to be monitored. help us through to weaning Once we have a best bet for each class of country then Weather patterns are unreliable and unpredictable. we need to trial how they can best be established. However implementing a grazing system that enables us to grasp any opportunity to spell AOSTD hill country Soils through its growing season may enhance the sustainabil- Low pH and high aluminium levels are clearly impacting ity of the legume content of this country. current legume production in the High Country. This grazing system has been trialled the last 3 years at There have been trials done at Glenfoyle but further Bogroy and Simons Hill. Anecdotal evidence is encourag- work is required. ing. Further work is required to: The interaction between soil pH and Aluminium is soil  Monitor legume growth and production. type specific, so solutions will tend to be property spe-  Refine grazing management for optimal grazing cific. time and optimal spelling time. Questions farmers will have are:  Refine grazing management for optimal block size  How much capital lime will be required to bring and grazing intensity. my soil pH back to an optimal level for this proper- Challenges ty ? In the initial years of oversowing the environment was  How much maintenance lime will be required to mostly just tussock and bare ground. With little competi- maintain it at this optimal level? tion for moisture legumes established readily. Now with  Will this be economic ? rhizomatous grasses and hieracium competition for  Should I instead be looking at low pH aluminium moisture is severe. tolerant species such as russell lupin and lotus for Every new legume species considered for introduction my low pH class of country? has to get over much higher hurdles for establishment  Should I consider adding lime to my current ferti- and survival. liser plan to prevent pH falling below the optimal Legume trials range? The MNZ Forage Project, along with Lincoln University Implications for Ida Valley Station looked at suitable legumes for the High Country and that John, Callum, and Dougal have voiced concern about the work will be reported in detail elsewhere. My farmer ob- decline in oversown and topdressed Hill Country, and servations were: have been actively participating in soil testing and mod-  Establishing anything directly without spraying in- elling. They realise that there is unlikely to be a silver to a rhizomatous grass sward was impossible, bullet and that change will be incremental. even with a specially modified direct drill adapted They have accepted that pushing lucerne production into to remove more of the competition, in a similar the hill country is a viable alternative to them. Given the way that the old Jethro Tull drill did. advice they have received, and the advisors and farmer  Triple spraying ( autumn, spring, predrilling) a rhi- mentors that are available to them, I am certain that this zomatous grass sward allowed good establishment will be achieved very successfully.

Once lucerne is established they will have the ability to and the Patterson family have indicated that they are spell some of the oversown blocks during the growing keen to participate and contribute some funding. What period by removing lambs as soon as lambing is fin- we have here is young farmers that are keen to partici- ished. Further monitoring of this strategy in the interim pate in research, build their skills, and add value to the may provide further guidelines. high country land, that they have been entrusted to Beyond this point there is currently no recipe. manage. There are broadly 2 main classes of country remaining : These issues are not unique to Ida Valley, but are found on nearly every high country run. The remainder of the front country where pH is generally adequate but hieracium and rhizoma- This research and funding requires industry wide contri- tous grasses are supressing legumes. The cur- butions. rent options here for legumes are lucerne, red The model we have here of young farmers starting with and white clover, and balansa annual clover, but the known science and optimising production within establishment is a hurdle that needs further re- those parameters, while researching options for the search. next stage is a model we should all get behind. The back country around the Poolburn Dam which is generally low in pH. The options here are to ad- Vision without action is just a dream dress the low pH with whatever the relevant Action without vision is just activity amounts of lime might be, or to trial establishment methods for low pH tolerant species such Action and vision together can change the course of as russell lupins or lotus. the world All of these options require further research and trials

NINE MILE PASTORAL LTD Direct drilling is used for all pasture renewal with ryecorn used as the preferred break crop for lighter dry- GORDON AND SPIN LUCAS land pasture renewal while heavier land is sown in turnips and short rotation ryegrass. A small area of sum- Nine Mile Pastoral Ltd consists of two freehold proper- mer rape is grown under irrigation for lambs if neces- ties, Nine Mile and Willowbank. Situated in the Lindis sary. Valley 16km from Tarras, Nine Mile comprises 2223 hectares ranging in altitude from 350m to 1200m, of which 300ha is above 900m. Annual average rainfall is 500mm with dry summers and 100+ days nil growth in winter. The property is subdivided into 20 hill blocks varying in size from 50 ha to 160 ha and 40 improved paddocks. Gordon moved to Nine Mile in 1961. The property at that time ran 800 Half Bred ewes, 700 wethers and 400 hoggets.

Irrigation Water - 14 ltr/sec x Eight Mile Creek with summer flow drop- ping to 50%. - 28 ltr/sec x Nine Mile Creek with summer flow to 50% - 34 ltr/sec x Lindis River - transferred x Willowbank (under development). Faithfulls flat looking into the Sunny hill blocks Supplements Approximately 350 tonnes of silage and 400 round bales The sunny country had been badly degraded by rabbits of lucerne hay are fed each year along with 10 tonnes of (although rabbit numbers were not high when he took purchased barley. Frequently surplus hay is made and over) and Gordon implemented a Catchment Board either sold or retained in reserve as a risk management Farm Conservation Plan that involved seeding, fertilising strategy. and setting aside the land which was left ungrazed for 5 years to restore vegetation and build a seed bank. This Fertiliser set the hill country up and it is still in very good heart Approximately 600 ha of hill country is fertilised each today – among the best in the region. year on a 3 year rotation with all improved paddock In 1989 the flock was changed to Merinos to take advantage of the much higher price Soil Tests pH Olsen QT QT QT QT S S fine wool was achieving at the time, selling P Ca Mg K Na the half Breds and purchasing various lines Eight Mile – hill 5.9 15 5 17 11 1 3 of annual draft ewes for a number of years. Mid Sunny – hill 6.0 14 9 30 15 1 9 Pastures Translator - hill 5.6 17 6 24 15 1 8 1800 ha oversown tussock hill (Cocksfoot, Top Nine Mile – hill 5.3 16 5 22 11 1 7 brome, clovers and native grasses) Peak Block – hill 5.6 26 7 27 18 1 10 300 ha cultivatable dry land - 155 ha lucerne BigSpend–developed 5.2 26 7 22 13 2 9 - 35 ha lucerne / grass mixes Bottom Faithfulls - lucerne 6.4 22 10 21 5 3 8 40 ha k-line irrigation No. 1 Downs - lucerne 6.2 28 10 14 9 2 7 20 ha pivot irrigation - Ryegrass / clover mixes and lucerne Stockyard South – k-line 6.5 42 9 24 9 3 4 63 ha unimproved Pivot 5 - irrigated 6.7 20 6 15 6 1 2

30 country receiving an annual fertiliser dressing. Performance 2012-13 Ave Merino

Some lime is now being applied annually to the hill to Lambing % 115% 84% offset a gradual decline in soil pH. Wool (kg/ssu) 6.02 4.94 Sheep Wool income/ssu $59.81 $52.54 All sheep carried on the property are Polled Merinos including a Polled Merino stud. The stud was registered Sheep income/ssu $74.97 $36.39 4 years ago after many years of breeding and selecting Total Income/ssu $134.78 $90.54 from elite animals within the flock with the goal of developing a versatile sheep that produces high quality Farm Working Exp/su $76.99 $55.45 fine wool on a larger plain bodied frame with a meaty Farm Surplus/su $52.66 $35.09 carcass capable of high lambing performance. The Lorel- mo Stud in Australia has had a strong influence on the The property is currently subdivided into 27 paddocks progress made with impressive results achieved to date. from 2 ha to 24 ha. The larger paddocks will be subdi- Approximately 100 rams are sold annually with numbers vided further as they are sown down but remain un- increasing each year as the stud grows. The majority of fenced while being cropped to capitalise on efficiencies AD ewes and surplus ewe lambs are sold privately for of larger paddocks. th breeding. Ewes are joined on May 10 with most ewes Irrigation wintered on the hill until shearing from which time they The property has undergone substantial development are fed supplements and ryecorn. Hoggets are wintered over the last 2 years with 3 pivots, a rotorainer and k- on turnips and lucerne hay. line now irrigating approximately 148 ha of the property. The irrigation system draws 85 ltr / sec of water from Stock Numbers 2013 2014 the Bendigo aquifer via a bore situated below the ter- race in the half pivot. Sheep: MA Ewes 3700 4337 The property was previously partially irrigated by border 2th Ewes 1500 1167 dyke system using water from the Lindis River. This was Ewe Hoggets 2650 2625 not very efficient as the flow reduced considerably over Stud Ewe Hoggets 400 400 summer making irrigation difficult on the free draining Stud Ram Hoggets 400 398 land with borders designed to operate with a specific Sires 80 76 volume of water. Cattle: Similar challenges were experienced under the rotorain- 63 80 MA Angus Cows er in soils with variable water holding capabilities. The 30 quantity of water applied and time between each irriga- R3 1st Calve Heifers 30 30 tion cycle on the lightest soils irrigated by the rotorainer R2 PTIC Heifers 47 53 were found to be unsuitable causing leaching of nutri- Calves 4 5 ents and a decline in pasture production. Bulls The system was changed to k-line shifted twice daily Sheep stock units 7695 7976 with a return period reduced to 5 days so that each application was then within the PAW of the soil and the Cattle stock units 905 872 return time meant pastures were much less likely to Total stock units 8600 8848 reach wilting point between irrigation cycles. This com- Stock units / ha 3.87 3.98 bined with soil and herbage testing prior to capital fertiliser application saw the pasture transform remarkably Weeds and Pests quickly to a deep green with much more clover activity than previously. The main weed threat is from briar with some burdock Pastures also present. Rabbits are under control. Willowbank is still in a transition phase having had sig- Willowbank nificant earthworks done to enable pivots to be in- Willowbank comprises 167 ha (155 effective) with a fur- stalled. Green feed cereals and brassicas have been ther 37 ha of DOC lease. used to generate seasonal quality feed while building organic matter on lighter ground and allowing weeds to Located approximately 10km south of Tarras and 26 km be dealt with. from Nine Mile at an altitude of 250 metres, the growing season at Willowbank is up to 6 weeks longer than Permanent pasture mixes are selected for production that of Nine Mile. and to maximise performance of the hoggets. In an

31 effort to reduce the winter crop and supplement use, Supplements pasture mixes include options to extend the pasture Supplements used winter 2014 -255 tonnes silage growth on the shoulders of the season as the challenge 440 baleage; 150 hay (90 x Nine Mile); 60 straw facing the property is to cost effectively manipulate the (purchased). feed supply to better fit the demand of the hogget finishing system. Fertiliser The intention is to also use cultivars in the pastures that A total of 62 tonnes (400kg/ha) of product was used on have good cool season performance mixed with high the property for the year 2013-14 at an average cost of quality species that perform well in the heat. All hogget $280.00/ha. brassica crops are sown with short rotation grass to provide feed in the spring for grazing and for supple- Sample ID pH Olsen QT QT QT QT S S ments. Kale is grown for cows with fodder beet to P Ca Mg K Na be grown this season for the first time. This is not Kale 6.8 26 7 21 13 7 18 without its challenges however as the close proximi- Bottom River 7.1 42 14 48 16 5 15 ty to vineyards means there are constraints when considering chemical weed control options. Carrot Wash 6.9 50 9 22 7 1 7 ½ Pivot Moata 6.7 29 6 20 8 5 3

Pivot 2 6.2 27 6 21 9 3 19

Poplar 7.5 24 18 38 6 7 185

Top G/house 6.4 17 4 16 5 5 3

Bottom G/house 6.6 13 6 20 6 8 3

Stock System Willowbank is used primarily for the purpose of adding value to surplus stock bred on Nine Mile with surplus feed produced currently utilised by winter dairy cows. This will not necessarily be a long term land use but is a development tool in the short term. The merino lambs arrive from Nine Mile in late January/early February with approximately 500 sold pre-winter and the remainder sold from August to November. The goal is to take advantage of the genetic potential of the cryptorchid lambs and maximise value by taking them through to 50kg+ live weight to produce 22kg+ carcass weights. Lambs sold in May/June usually average 19kg Cover - summer 2015: CW. 10.3 ha lucerne Finishing the merino male lambs at Willowbank is the 13 ha lucerne / prairie / plantain preferred use of the property because: 13.7 ha fescue / red / white / plantain  Merino hogget finishing using Nine Mile genetics 19 ha ryegrass / clover pasture produces a return that is competitive per kg dry 27 ha short term grass matter with alternative high returning dry stock 7.4 ha oats (WCCS) > turnips / annual grass options of land use. 18 ha kale  Finishing the Nine Mile progeny provides good 10 ha fodder beet information at a commercial level on the genetic 25 ha rape / annual grass progress being made for meat production and car- 11.5 ha turnips / annual grass cass traits in the stud.

 The policy retains control over timing, quantity WCCS=whole crop cereal silage and quality of stock supplied to Willowbank.

Feed Supply/Demand Hoggets / Dairy Cows / Lambs / Supplements While irrigation provides the certainty of production to ensure reliable summer finishing capability, the natural growth curve of the irrigated pasture based system is entirely at odds with the feed demand of the hoggets. In late spring and summer when daily pasture growth rates peak there are almost no animals on the property so during this development phase, brassica crop is used as the most cost effective means to transfer the feed surplus to better fit the hogget demand and maintain feed quality.

Stock Numbers 2013 2014 Merino hoggets 2700 2800 Dairy Cows 400 620 Hoggets / Lambs / Dairy Heifers / Supplements

Sheep Stock Units 1890 1960

Cattle Stock Units 3200 4960 Adjusted Stock Units 1710 2040

SU per eff hectare 11 13.2

Hogget Performance 2012-13 Weaned weight 28kg Sale weight 47.2kg Av days wean to sale 209 Average gain (gm / day) 92.1 Gross Margins

Financial Returns $ per Hectare The gross margins in the table below show that Merino hogget and lamb finishing is financially very competitive Gross Income $2,600 despite hoggets spending 100 days on crop and supple- Farm Working Expenses $1,550 ments. The margins assume the best lambs finished and Cash Farm Surplus $1,050 sold prior to winter are fed entirely on rape and Moata from arrival.

Effect of Alternative Feed and Stocking Systems on Feed Supply / Demand A number of stock and feed systems were modelled to assess profitability and best fit to the growth curve, in- vestigating options that might require less crop and reduce cost. Hoggets / Lambs / R1 & R2 Beef / Supplements

IRRIGATION DEVELOPMENT Field Capacity 24 hrs following saturation, after drainage or what can WILLOWBANK be held under gravitational forces . Tim O’Sullivan, Sustainable Water Trigger Point Willowbank’s irrigation development dates back some When to start irrigating, midpoint between field capacity 60 years. Borderdyke irrigation was construction in the and stress point. 1950’s to approximately 50% of the property where it Stress Point drew its water off the Lindis River. This was pioneering Soil moisture becomes limited which results in stress on stuff however reliability was always an issue particularly the plant, will begin to wilt but often catch up during the in recent times. night. Permanent Wilting Point (PWP) In 2010 they applied to shift the Lindis take upstream to The ability to draw water is lost, > 15 Bar suction re- Nine Mile station in the Lindis Pass and applied for con- quired. sent to drill for water on Willowbank. With sufficient water being sourced they employed PGW Water to design Graph illustrating typical moisture cycle during an irrigation and develop the current overhead spray system. This season consists of 3 x Valley centre pivots irrigators, 1 x M125 Roto Rainer and 14 ha of K-line. Some refinements following the original install involved reducing the return rate of the Roto Rainer from 10 to 8 days and employing more K-line to compensate for this. The capacity of the system is based around a daily gross application of 5mm/day and comes under pres- sure during the heat of the summer.

The pivots, being relatively short, are deemed to be very efficient at applying water as there instantaneous Graph illustrating typical moisture cycle during an irriga- application rates don’t exceed 10mm/hr which is less tion season. Blue curve illustrates extreme applicators than the infiltration characteristics of the soil meaning such as borderdyke and the green curve illustrates re- run off/ponding is mitigated. duced and more regular applications from pivots. Purple General terms associated with irrigation honeycomb zones portray limited growth due to excess Gross application rate water ie saturation or beyond stress point. Strictly speaking volume over area, 50m3/ha = 5mm day. Net application rate Willowbank with the 4 respective soil types What is left in the root zone after an irrigation event i.e. gross application minus losses such as evaporation, runoff & operating time i.e. 18 out of 24 hrs. Return rate Number of days required for the applicator to return to where it started expressed in days. Application rate The average application depth applied in an irrigation event expressed in mm. Infiltration rate The ability for any given soil to absorb water measured in mm/hr. Instantaneous Application rate (IAR) The intensity of watering, ie how many mm are applied in any given time period, measured in mm/hr. Irrigation/System capacity The system’s ability to apply water and meet periods of high ET i.e. efficient applicators with reduced return rates. Saturation The entire soil is saturated which results in a period of drainage out the bottom of surplus water and nutrients.

The table below categorises the 4 different soil types on Willowbank. Although being mapped as different soils there is still quite a range of variability amongst the specific types which is typical for immature alluvial soils.

Soil Types at Willowbank – Tarras

Profile Available Water (PAW)

Soil Type Depth Tex- Drain- Permea- 0-100cm or 0-60cm or 0-30cm or Irrigability class ture age bility pro- root barrier root barrier root barrier Profile Class file Swanloam Shallow Loam Poorly Rapid Very high High Moderate Flat to very gently (Typic recent (20- over drained (126mm) (103mm) (81mm) undulating land with Gley Soil) 45cm) Sandy moderate drainage/ Loam permeability re- strictions and soils with high PAW

Ripponvale Shallow Loam Well Rapid Moderate Low Low Flat to very gently (Typic Imma- (15- Drained (69.4mm) (59.1mm) (42.4mm) undulating land with ture Semiarid 45cm) good drainage/ Soil) permeability re- strictions and soils with low PAW

Matapihi Moder- Loam Poorly Moderate Very High Very High Moderate Flat to very gently (Typic Recent ately over Drained (174mm) (119mm) (66mm) undulating land with Gley Soil) Deep Sandy moderate drainage/ (50- Loam permeability re- 95cm) strictions and soils with high to very high PAW Manuherikia Moder- Loam Well Moderate High Moderate Low Flat to very gently (Laminar Ar- ately over Drained (101mm) (71.8mm) (37.8mm) undulating land with gillic semiarid Deep Sandy good drainage/ Soil) (45- Loam permeability and 90cm) soils with moderate PAW

* Information obtained from S-Map on 10th October 2014

Recent technologies that are enabling Costs range from $8k-$12k/ha, control biggest greater efficiency influence a. Nozzle control on pivots d. GPS technology Great technology Available for shifting -K line and long line sprinklers Various systems available to promote accurate shifting Plants use water not soil! Summary b. Soil moisture metering Each system has its own set of both positive and nega- tive attributes Sometimes only as good as the overall installation  Pivots particularly in this environment are king Provides or fast tracks ones understanding of soil however careful design is still imperative… science  Knowledge – know and understand your soils and Really only comes into its own when having a sys needs before embarking on irrigation installation tem with high capacity  ‘Measure and monitor’ as this encourages effi- c. Fixed grid sprinklers cient use of water which results in extra produc- Relatively new for broad acre agriculture tion. Many systems being trialled and will continue evolving Thanks to Pete Young for preparing handout material. Effectively achieve or replicate pivot as far as watering as little and often….

A DESCRIPTION OF THE OVERSEER® nutrients or the effects they might have on the environment. NUTRIENT BUDGET MODEL  It assumes that ‘good farm management practic- Dr A H C Roberts, Ravensdown es’ are implemented. Introduction  It is designed to be an expert system, and users should understand nutrient management science A farm nutrient budget is a summary of nutrient inputs and farm systems, and only model realistic farm and outputs. An early application of nutrient budgets systems. was to determine whether inputs of nutrients are inade- What does this mean for the user? quate relative to outputs, leading to a decline in the soil nutrient status. Conversely, a nutrient budget identified Quasi-equilibrium? if excess nutrients were being applied and accumulating The model assumes that inputs and farm management above required levels. Nutrient management plans practices are in near equilibrium with farm production could then be developed to address such inefficiencies, (animals grazed, product removed such as supplements, with benefits to the farm’s bottom line. milk, live weight, wool, and crop yields). Hence it does The challenge then is how to calculate a nutrient budget, not model well a farm conversion from a sheep and beef particularly in complex farm systems. This is particularly farm to dairy farm, or from conventional fertiliser to the case with pastoral systems where nutrient transfer slow release fertiliser. around the farm is mediated by grazing animals. OVER- SEER® Nutrient Budgets version 6 (Overseer) is a soft- Annual average? ware tool (owned by the Ministry for Primary Industries, For a specified farm system, the nutrient budget is an the Fertiliser Association and AgResearch) that models estimate of the annual average outputs for the given these complexities to calculate a farm nutrient budget, climate pattern if the management system described and has been used for many years by the fertiliser indus- remained in place. Overseer is not a short-term, tactical try to underpin fertiliser recommendations on pastoral model and therefore does not model within and be- farms. tween years’ short-term climatic, production, or man- An important component of a nutrient budget is the loss agement variability. of nutrients from the farm, either as removal in product Good practice? or as losses in gaseous emissions, leaching and/or runoff. In recent times Overseer has been used in a plan- Generally, Overseer assumes that a range of ‘good man- ning and regulatory context to inform and implement agement practices’ have been, and are being, imple- regional council water quality nutrient management mented. For example, if effluent is applied, it assumes plans and as part of industry audited self-management that daily management follows good management prac- processes. Understanding how the model works and the tices, and if fertiliser or effluent are applied Overseer consequences of selecting and then modifying input var- assumes the stated rate is applied evenly over the whole iables must be well understood. area (block) indicated at the time stated i.e., there is no ‘poor management’ that would result in ‘large’ discharg- Overseer - a basic description es. Overseer aims to be a practical tool relying on input data Overseer does allow modeling of some ‘poor practice’, that are readily obtained, and aims to model most major for example: farm systems across all regions of New Zealand. Its scope and underlying assumptions are well documented  Nitrogen fertiliser– applying large amounts in the on the Overseer website (www.overseer.org.nz) but are winter or applying more than is required for the worth summarising: level of production;  It can model many enterprises including dairy,  Over-irrigating– causing extra drainage (and sheep, beef, deer, dairy goats, fruit, vegetables leaching). and arable crops. Losses to edge of farm?  It models nitrogen (N), phosphorus (P), potassium (K), sulphur (S), calcium (Ca), magnesium (Mg), Overseer estimates nutrient losses from a farm, i.e., sodium (Na) as well as hydrogen ions (H+). what leaves the root zone, flows over the soil surface  It calculates annual average nutrient budgets for beyond the farm boundary, or volatilises into the atmos- systems assumed to be at ‘quasi-equilibrium’. phere. Products, supplements or effluent imported or exported are also accounted for when they cross the  It estimates losses of nutrients to the edge of the farm boundary. Overseer does not model processes that farm, and the bottom of the root zone i.e. it does may affect nutrients beyond these boundaries e.g., dilu- not model what subsequently happens to these tion, dispersion, assimilation and other attenuation pro-

38 cesses that may increase or decrease the concentration part of the farm; either that animal is moved and ex- of for example, N or P in any eventual receiving water. cretes in another paddock or if excretion occurs in the farm dairy or feed pad, it will be captured as effluent and Expert system? spread onto a farm block or blocks or exported off farm. There will always be a tension between having the mod- In terms of the pastoral agricultural model (dairy, sheep, el ‘accurate’ and able to adequately capture complex beef, deer, etc.) the central model is not based on a pas- farm systems, and the desire for an easy to use model. ture growth or a soil fertility driven model but is actually To obtain meaningful outputs, Overseer should be used an animal intake model. The model calculates the ener- by trained and qualified people inputting data following gy requirements of the block/farm based on the live- the OVERSEER Best Practice Data Input Standards (see stock information (milk production, stock numbers and www.overseer.org.nz) with sound knowledge of New classes, management, etc.) provided by the user. With Zealand farm systems. this information, plus an energy calculation from any How does Overseer calculate a nutrient budget? supplementary or crop feed used, the model then estimates the amount of pasture dry matter (taking into ac- The example nutrient budget (Figure 1) shows the out- count pasture quality i.e., its energy content) that must comes of the calculations, reporting sources of nutrient have been consumed; and also how much has been inputs, estimated removals (in produce, exported ma- grown (by using default or entered pasture utilisation nures and losses) as well as changes to nutrient stocks in data). the soil. These calculations can be reported for an individual management block or at the whole farm level Nutrient intake by the herd or flock is calculated from (area weighted average of the blocks plus non-block the calculated dry matter intake and estimates of nutri- losses such as those from farm infrastructure, effluent ent content of pasture and feeds (from Overseer data- storage etc.). bases). Estimates of nutrients removed in products (e.g., milk, wool, carcasses, and crops) Figure 1: Expanded nutrient budget report for Willowbank allow calculation of excreted nutrients and their partitioning between faeces and urine. Further to this, a number of other data inputs are required to describe the farm system so that the model can estimate how much nutrient is deposited directly back to paddocks and, in the case of dairy farms, how much is captured as effluent. The modelling of nutrient transfers is about estimating how much nutrient is deposited when and where. A range of nutrient sub- models are then applied to this information to estimate the fate of those nutrients. Overseer is a combination of sub- models, many of which have been published and peer reviewed. Most are adaptations of published models (e.g., hydrology, animal metabolism, soil nutrient models, P runoff,) but some are specific to Overseer (e.g. N leaching model, arable crop models). The innova- tion aroundOverseer is all about As an example of nutrient (fertility) movement around (a) capturing of nutrient transfers at the farm scale (b) the farm: fertiliser nutrients applied to and taken up by how these individual small-scale models are combined the pasture in one part of the farm will be consumed by to be able to scale up to a block/farm, (c) the develop- the grazing animal and could be transferred to another ment of databases (e.g., climate, temporal variation in

39 pasture nutrient content) that underpin the model and Leaching risk increases with decreasing soil available wa- (d) the development of approaches to deal with chal- ter capacity (AWC) (less nutrient retentive soil) and/or lenging topics such as nutrient deposition in laneways increasing drainage. For example, with two soils, one and hard surfaces, where published information is gen- with an AWC of 120 mm and one with an AWC of 40 mm erally lacking. and 160 mm of drainage, the soil with the higher AWC will only be ‘flushed’ 1.3 times compared to 4 times for Willowbank nutrient budget (2013/14) as an example the soil with the low AWC. This increase in ‘flushing’ will increase the proportion of total N leached. Given the Referring to Figure 1, which is the whole farm nutrient sensitivity of N leaching estimates to this soil property budget for Willowbank Overseer calculates N inputs and drainage, this emphasises the need for the user to from fertiliser (61 kg N/ha) and estimates that 111 kg input accurate information for these variables. N/ha comes mainly from biological nitrogen (clover) fixa- Note also that there is ‘inorganic’ or mineral N surplus in tion. Based on production data entered by the user, the soil profile i.e., not all the mobile N is leached within Overseer estimates a removal of 28 kg N/ha in produc- the reporting year and that the P and K ‘balance’ is posi- tion (meat and wool). Overseer has calculated how tive (Figure 1) indicting that soil levels for these nutrients much, where, when (and in what form) N has been de- will increase with time. posited. Sub-models are then applied to these N sources to estimate losses. The result is an estimated loss of 52 Soil available water capacity kg N/ha, with nearly 75% (39 kg N/ha) in gaseous form Overseer has a database of soil properties provided by (ammonia, nitrogen gas and nitrous oxide) and around Landcare Research. Selecting soil series, soil order or soil 30% or 13 kg N/ha is lost below the root zone, of which 5 group invokes default soil properties (including AWC) kg/ha is coming directly from urine and the other 8 kg from the database. These can be further modified by N/ha from soil, mineralisation of organic matter in crop- selecting a soil depth and the nature of the subsoil. Over- ping blocks and infrastructure. Timing of cultivation, fal- seer provides algorithms for these soil properties and lowing and establishing crops relative to when soil drain- their influence on N leaching estimates. Selecting the age occurs all contribute to this loss and is a place to correct soil type, representative of the block is critically start if reductions in N loss are required, if it is practical important; and becomes especially important on shallow to make any changes. soils where small changes in estimated AWC can have a Willowbank is in an area designated ‘rest of Otago’ un- large influence on N leaching estimates. As a conse- der Plan Change 6A which allows farmers to leach up to quence, guidelines for defining shallow soils have been 30 kg N/ha before moving from a Permitted Activity con- developed and an S-map integration facility is being de- sent status to a Restricted Discretionary consent require- veloped. ment. Drainage Given that the 2013/14 nutrient budget represents the Drainage is estimated by Overseer using a hydrology average long term conditions on this property the N loss model developed by National Institute of Water and At- as a whole property is well below the 30 kg N/ha thresh- mospheric Research and AgResearch scientists. Overseer old. However, if the situation arose where some reduc- requires an annual rainfall input. The model then uses a tions in N loss were required an examination of the indi- set of ‘typical’ average regional distributions of that rain- vidual block N loss estimates would assist in indicating fall to calculate daily rainfall in a typical year. The drain- which blocks would need to be scrutinised to see what age model is then applied to this daily distribution. There management changes could assist in reducing the N loss are usually considerable differences between long-term i.e., it helps identify the ‘hot spots’ on the farm. average rainfall and an individual year’s total rainfall and Clearly, the different blocks comprising different forages monthly distribution. and different classes of animals grazing them differ in their N losses (Figure 2). The N lost to water (kg N/ha) The typical ‘average year’ rainfall patterns result in calcu- column differences are caused by varying combinations lated drainage peaks in the winter months, making urine of cultural practices, N fertiliser additions, irrigation deposited in autumn/early winter most susceptible to practices and animal grazing management. The two leaching. As rainfall increases the estimate of N loss in- highest N loss blocks (Moana/Turnips and Rotorainer creases because total drainage is higher and there is an Rape+Moana) had an estimated drainage of ~250 mm/yr increase in the number of months in which drainage oc- and irrigation practice, N fertiliser use and timing of graz- curs. ing could be scrutinised to see what, if anything, could Irrigation be done to reduce N loss without impacting negatively on productivity. Most of the other blocks had estimated Where irrigation is used, this effectively increases the drainage of ~100mm/yr while the Lucerne and Unim- amount of water added to the soil and hence can result proved Land blocks only drained around 30-40 mm/yr. in more drainage as a result of inefficiencies in the irriga-

40 tion procedures, and due to the soil profile being wetter, velopment to deal with complex crop rotations. especially on the ‘shoulders’ of the drainage season. This Accuracy and errors associated with N loss esti- is likely to result in higher N loss estimates than would mates occur in the same situation without irrigation. If a specific irrigation amount is entered into Overseer, this Accuracy of a measurement is the closeness of that should be commensurate with the entered annual rain- measurement to the quantity’s actual (true) value, and fall. A Technical Note that describes this issue and poten- error is the level of disagreement between a measured tial solutions is available on the Overseer website. value and the true or accepted (where actual measurement is difficult) value. This concept has limited applica- Model comparisons bility to the estimate of whole farm nutrient loss where Overseer is a mathematical representation of complex it is not practicable to measure this directly. bio-physical management systems and therefore may Uncertainty in the context of a model like Overseer can not always accurately reflect what is actually occurring. be defined as the combination of uncertainty from the However, the model outputs are the best currently avail- modelling process and uncertainty from incomplete able estimates because the model has considered nutri- knowledge. This concept is most applicable to the use of ent movements over the whole farm and is constructed Overseer given that the number of assumptions and er- with the best available scientific information. There has rors in sub-models produce a level of uncertainty about been a series of regular updates of the model to keep the estimate of nutrient losses. It is not currently possi- pace with evolving farm systems, user requirements and ble or appropriate to specify a generally applicable un- new science. certainty for Overseer nutrient loss estimates. Overseer estimates of N leaching have been compared Conclusions with measured N leaching data from dairy farmlet stud-  Overseer is the best available tool to construct an ies in the Waikato, Manawatu and Southland where an- annual nutrient budget, using readily available nual rainfall has been less than 1400 mm and less than information and the best available science to cap- 200 kg N/ha as fertiliser has been applied annually ture the complexities of many New Zealand farm (Figure 3). At the lower end of the N loss range (i.e., less 2 systems. than 60 kg N/ha) the correlation (r = 0.83) between measured and Overseer N leaching estimates is very  Overseer is based on a considerable body of pub- good for a biological model. licly available scientific research and investigations (www.overseer.org.nz). Many of the individual model components have been independently reviewed. The ultimate challenge is the  Overseer is a robust tool to test different in- current inability to validate the ‘end result’, i.e., whole put/management strategies to provide infor- farm N leaching. Even with the farmlet trials, validation mation on the implications that these changes has been undertaken at the block level. It is currently would have on nutrient cycling and nutrient loss- impracticable to validate at a farm scale because it is not es. feasible to measure nutrient losses at the whole farm  Appropriate application ofOverseer requires a scale. thorough understanding of farm systems in gen- Cropping eral, as well as the individual farm system being modelled, training in the use of Overseer and the Much of this article has focused on pastoral farms. Many application of generally agreed practices for input of the points raised about use, interpretation and valida- variable choices. tion are equally applicable to the other enterprise models within Overseer, as testified by the recent Foundation Acknowledgement for Arable Research (FAR) review of the cropping model. Dr Alister Metherell assisted in modifying the nutrient While concluding that the current model “…is the best budget so that it produced the necessary reports in the tool currently available for estimating N leaching losses latest release of Overseer Version 6.1.3. from the root zone across the diversity and complexity of farming systems in New Zealand”, the review found that there were areas that needed addressing to improve the utility ofOverseer for arable/vegetable system use. The FAR review concluded that the simplifications used in the arable/vegetable models are consistent with the approach taken in modelling pastoral systems within Over- seer but contrast with approaches taken in other crop- soil interaction models. The FAR review also concluded that Overseer needs further testing and validation under cropping systems and the user interface needs more de-

Figure 2: Nitrogen Block report for Willowbank

Figure 3: Measured N loss data for farmlets and Overseer modelled N loss estimates

WATER ALLOCATION IN OTAGO

Water Quantity

Otago Regional Council administers water allocation in Otago through Plan Change 1C, water quantity, which came into effect st1 March 2012. The plan requires that water will be managed in a sustainable way. Water will allocated on an efficient use basis with refer- ence to local rainfall and soils. Irrigators will need to have a minimum of 5 years of records to demonstrate use of water Consultation with affected parties is required as part of the consent process, comprising IWI, DOC and Fish & Game. Residual flows will be set for recognised instream values within tributaries Minimum flows will be set for mainstreams Consents may be granted for up to 35 years Measuring and reporting of water takes national regula- tions,2010, also requires irrigators to provide records to Regional Council of annual water use. Many farms are presently changing from border dyked irrigation to pivot spray irrigation. This improves water efficiency and will assist in meeting discharges to surface water under Plan Change 6A.

The move to more efficient irrigation use coincides with the need to transition from deemed permits, which ex- pire in 2021, to resource consents.

Water Quality Timeframe for permitted contaminant discharges to Water Plan Change 6A meet discharge thresholds (Schedule 16) is 2020. Surface water

Plan Change 6A came into effect on 1st May 2014 and is Schedule 16 and surface water discharge about protecting good water quality while minimising thresholds constraints on land uses and the way rural people man- Central Otago and Upper Clutha age their land  Economic use of productive land will continue NNN, Nitrite-nitrate-nitrogen 1.0mg/L  An effects based, permitted activity approach DRP, Dissolved reactive phosphorous 0.035mg/L  Provides opportunity for land managers to decide NH4, Ammoniacal nitrogen 0.2mg/L how to best manage their properties to meet wa- E Coli 550cfu/100ml ter quality standards  Schedule 15 describes good quality water for catchments  Schedule 16 describes contaminant discharge concentration thresholds for nitrogen, bacteria (E.coli) and phosphorus  Time is allowed for land management changes When do the rules come into effect? All rivers and lakes to achieve the required good water quality standards (Schedule 15) by 2012 or 2025 – Table 15.2 of plan.

Water Plan Change 6A  Silage leachate Ground water Permitted activities and stock Nitrogen loadings and ground water protection Stock access to waterways is permitted provided there is Three nitrogen loading zones with a limit of 15, 20 and 30 kg per ha per year have been established. To be as-  No feeding out on the bed or on a significant wet- sessed by Overseer 6. land Alpine lake catchments have a 15kg per ha N limit  No visual change in colour or clarity Relevant Nitrogen sensitive zones have a 20kg per ha N  No noticeable slumping, pugging, or erosion limit  No damage to fauna or flora of a significant wet- For the rest of Otago, the N loading limit is 30kg per ha N land limit Driving stock through waterways is permitted provided Nitrogen leaching rates must be met by April 2020 there is st From 1 May 2014, maintain a record of data to run  No crossing structure available for use Overseer.  No visual change in colour, or clarity after stock Prohibited Activities crossing has ceased  You can’t discharge the following contaminants in  No noticeable slumping, pugging or erosion any lake, river or Regionally Significant Wetland. Gross discharges, oil, grease film, scum or foam  Discharge from effluent sources  Sediment from disturbed land, without mitigation measures

NZGA WISHES TO ACKNOWLEDGE AND THANK ALL THE LOCAL SPONSORS THAT HELP MAKE THIS CONFERENCE A SUCCESS

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LOCAL ORGANISING COMMITTEE: Vanessa Hore (Chair), Kate Scott, Matt Hore, George Collier, Scott Levings, Warwick Hawker (CODC), Pat Garden, Julie Kearney, Scott Perkins, Liam Donnelly, Bevan McKnight, Peter Young, Jane Mitchell and Graham Kerr (NZGA Exec)

With thanks to J. Kearney, G. Ogle, P. Young, D. Fastier, A. Roberts, T. O’Sullivan and ORC for handout material and to Grant Calder for organising bus commentaries

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