6th International Scientific and Expert Conference TEAM 2014 Technique, Education, Agriculture &Management Kecskemét, November10-11, 2014

IMPLEMENTATION OF IRRIGATION SCHEDULING BASED ON MONITORING OF SOIL MOISTURE CONTENT IN EXTREME WEATHER CONDITIONS M. Marković1*, J. Šoštarić1, M. Josipović2, D. Petošić3, I. Šimunić3 and V. Zebec4 1Department for Agricultural Amelioration, J. J. Strossmayer University of Osijek, Faculty of Agriculture, Republic of Croatia

2Department for Agricultural Technique, Agricultural Institute in Osijek, Republic of Croatia 3Department for amelioration, University of Zagreb, Faculty of Agriculture, Republic of Croatia 4Department for Agroecology, J. J. Strossmayer University of Osijek, Faculty of Agriculture, Republic of Croatia *Corresponding author e - mail: [email protected]

Abstract Several studies in different environmental condition The purpose of irrigation scheduling is to make a have shown that irrigation practice contributes to - decision when and how much water apply to the NO3 contamination of surface and ground water field. There are many advantages of irrigation [2], [3], [4], and [5]. Authors claim that it is scheduling and one of the most important is to important application of irrigation water and maximize irrigation efficiency by saving of irrigation nitrogen fertilizers to meet but not exceed crop water and energy as well. Also, there are different requirements, while prudent irrigation scheduling methods for irrigation scheduling which are minimizes nutrient leaching and maximizes consisted on several criterion. One of the most irrigation efficiency by reducing energy and water common used criterion in scientific research and use. On the other hand scientific researchers are agronomic practice is monitoring of soil moisture mostly focused on yield reduction under drought content during the period of growth. The stressed condition, especially in sub humid and discussion in this paper is limited to the use of arid areas [6], [7], [8], [9], [10]. According to some electrical resistance blocks in irrigation scheduling. previous analysis made by Šoštarić [10] area of Furthermore, the efficiency of electrical resistance eastern Croatia with highly intensive agricultural blocks in extreme weather conditions. The analysis production is affected by changes in climate and of results indicate that proper irrigation scheduling global environmental conditions. Eastern Croatia has important role in preserving water and has experienced increases in air temperatures achieving high yields of maize, especially in during last 12 years (2010-2012) which amount up extreme weather condition. Furthermore, to 2.2 0C (2012) in compare to long term average application of electrical resistance block is useful (LTA = 1961-1990). As it has been presented in tool in indirect measuring of resistance and soil Figure 1. in same period the amount of rainfall in water content. several years was significantly above LTA (2001, 2005 and 2010) yet there are 6 years with drought Keywords: stressed condition when yields of summer crops Irrigation, scheduling, electrical resistance block, where extremely low (2000, 2003, 2007, 2009, extreme weather 2011 and 2012).

1. Introduction Irrigation scheduling can be described as management process used by irrigator managers in order to determine the frequency and duration of watering. As it has been presented by Brouwer [1] “The irrigation schedule indicates how much irrigation water has to be given to the crop, and how often or when this water is given”. It is the strategy which can prevent over application of water and minimizing yield loss due to water shortage or drought stress. Several negative consequence can come as a result of excess water applied thru irrigation system: oxygen deprivation, impaired root respiration, infection by disease organism and most of all it comes to yield Figure 1. Variation of rainfall amounts (mm) for reduction, nutrient leaching and economical losses. Osijek area in growth period 2000-2012

M. Marković, J. Šoštarić, D. Petošić, I. Šimunić, V. Zebec 1 6th International Scientific and Expert Conference TEAM 2014 Technique, Education, Agriculture &Management Kecskemét, November10-11, 2014

Furthermore, not only there was significant lack of Figure 2. Electrical resistance block (Watermark rainfall but also uneven distribution of rainfall block, Irrometer Co.) during period of growth. Therefore implementation of irrigation scheduling in sub humid area (eastern Electrical resistance block actually measures soil Croatia) is required. Different methods for irrigation water tension expressed in cbar. The change in scheduling are demanding different approach. One soil moisture causes the change in water content of the most common criterion is monitoring of soil of block so the electrical resistance increases as moisture content. There are varieties of methods the water content of block decreases. The readings that can be used to measure soil water content. are taken by hand held device – Watermark meter, The discussion in this paper is limited to the use of Irrometer Co. (Figure 3) and they range from 0 to electrical resistance blocks in maize irrigation 199 cbar were 0 represents water content at field scheduling performed at Agricultural institute in capacity (FC) while 199 is the dry soil. Zero Osijek. The aim of this paper is to review the reading indicates to nearly saturated soil which current knowledge and previously published means that almost no energy is required to remove papers on the importance of irrigation scheduling water. Field capacity is upper limit of water for better water usage in extreme weather storage. It can be defined as the condition that conditions. exists after a saturated soil is allowed to drain to the point where the pull of gravity is no longer 2. Results and discussion sufficient to remove any additional water. Opposite to FC is permanent wilting point, the lowest Electrical resistance block moisture level at which plant cannot recover the drought stress. Monitoring of soil moisture content includes different devices (time domain reflectometry (TDR), tensiometers, gravimetric method, neutron probe and electrical resistance blocks) for indirect measuring of soil-water status. Electrical resistance block (Watermark block) is made of gypsum (gypsum block) and it consist two electrodes enclosed in block. Electrodes are connected to a wires extend to the soil surface (Figure 2). Wires are one meter long what provides installation to different layers in soil.

Figure 3. Watermark sensor

Irrigation should be scheduled between these two values. The effectiveness of electrical sensor is soil condition dependent [11]. Reading result can be related to the soil water content by making a calibration curve because the relationship between soil water content and soil water potential is different for each soil type. In general, greater the clay content, greater water content at any water potential. Irmak et. al. [12] had stated that in sandy soil most of the pores are relatively large and once the large pores are emptied only small amount of water remains. For a fine, sandy soils very small increase in matric potential causes a more drastic decrease in water content then in other soil types. Beside the texture it is important to have a knowledge about main soil characteristics. Table 1. presents main physical properties of soil at trial field of Agricultural institute in Osijek.

Implementation of Irrigation Scheduling Based on Monitoring of Soil Moisture Conditions in Extreme Weather Conditions 2 6th International Scientific and Expert Conference TEAM 2014 Technique, Education, Agriculture &Management Kecskemét, November10-11, 2014

Table 1. Main physical soil properties caused by excessive amount of rainfall. At dry farming WUE ranged from 14.28 kg mm-1 (2008) SD WC P (%) AC p CC,% to 16.48 kg mm-1 (2006). At A2 irrigation plots (%) (%) -3 (cm) (g cm ) WUE ranged from 16.21 kg mm-1 (2007) to 18.94 0-32 36.6 41.8 5.3 1.50 0-40 kg mm-1 (2009) while at A3 WUE ranged from 32-50 37.1 41.8 6.2 1.54 28% 16.90 kg mm-1 (2008) to 20.82 kg mm-1 (2010). WC=water capacity; P=porosity; AC=air According to results of analysis the lower amount capacity, ρ= soil density; CC = Clay content, % of plant available water the better is WUE since the highest WUE in all tested years is actually in year Results of irrigation scheduling in extreme with the lowest amount of rainfall (2009 = 230.8 weather conditions mm). Same result is in irrigated plots where the highest WUE is also recorded in 2009 at A3 For the purpose of analysis of irrigation efficiency irrigation plots with 240 mm of irrigation water (IE) in extreme weather conditions yield results which is the highest amount in all tested years. from previously published articles are used [13]. Furthermore, the analysis of IWUE shows better Water use efficiency (WUE) of maize is function of water use at A2 irrigation plots in average years multiple factors including physiological 2006 and 2008 while in dry growing seasons 2007 characteristics of maize, genotype, soil and 2009 better water use is at full irrigated plots characteristics like soil water holding capacity, (A3). This result is opposite to one published by meteorological conditions and agronomic practices Takac [17]. Author has stated that the highest [14]. Since water use efficiency (WUE) in its IWUE in dry years was obtained when low strictest sense does not take into account the role irrigation dosage were applied. of irrigation, definition of “Irrigation Water Use The exception in this research is extremely rainy Efficiency” by Howell [15] is more suitable for growing season 2010 when the highest yield of agronomic perspective because its take irrigation maize grain was at dry farming plots so according into account. Irrigation Water Use Efficiency to that the lowest water use was at full irrigated (IWUE) takes into account variation in yield of the plots (A3). Although the Watermark measuring same crop under different application of water [15]. results have shown water deficit in upper soil layer The analysis of WUE is calculated as follows: (30 cm) as it seems irrigation water have disturbed oxygen balance and air exchange which have (1) resulted with yield losses.

Table 2. Efficiency of irrigation scheduling in different climate conditions Where WUE is water use efficiency (kg mm-1), Y = yield of maize grain (kg ha-1) and ET = actual Irrigation regime A1 A2 A3 evapotranspiration from seeding to harvest (mm), 2006 - Y 8.5 9.3 9.6 [17]. Irrigation water use efficiency is calculated as IW (mm) 413.9 80 120 follows: WUE 16.48 18.03 18.62 IWUE - 10 9.2 (2) 2007 - Y 8.4 9.2 10.8 IW (mm) 301.7 120 200 Where IWUE = irrigation water use efficiency (kg WUE 14.80 16.21 19.03 mm ha-1, Yi = yield of maize grain in irrigated IWUE - 6.7 12 conditions (kg ha-1), Yd = yield at rainfed plots (kg 2008 - Y 8.2 8.9 9.2 ha-1) and Imm = irrigation water (mm), [18]. Results IW (mm) 437.3 80 120 of monitoring of soil moisture content are in close WUE 14.28 16.35 16.90 connection with weather conditions, particularly the IWUE - 8.8 8.3 amount of rainfall and distribution of rainfall in 2009 - Y 10.3 10.6 11.7 growing season as well. Amount of water added in IW (mm) 230.8 200 240 one irrigation interval was same for all years and irrigation regimes, 35 mm. Total amount of WUE 18.41 18.94 20.91 irrigation water was soil moisture dependent. Total IWUE - 1.5 5.8 amount of irrigation water added in each irrigation 2010 - Y 9.24 9.17 8.59 regimes (A2 and A3) as well as yields of maize IW (mm) 676.6 35 105 grain are presented in table 2. There are significant WUE 16.44 16.31 15.28 variation in amount of rainfall in selected years. For IWUE -2 -6.19 example significant lack of rainfall with drought A1 = dry farming; A2 = 60-100% FC; A3 = stressed conditions was noticed in growing 80- 100% FC; Y = Yield (t ha-1); IW = seasons 2007 and 2009. Opposite to that, growing irrigation water (mm); WUE = kg mm-1; IWUE season 2010 was extremely rainy with stress

M. Marković, J. Šoštarić, D. Petošić, I. Šimunić, V. Zebec 3 6th International Scientific and Expert Conference TEAM 2014 Technique, Education, Agriculture &Management Kecskemét, November10-11, 2014

= irrigation water use efficiency (kg ha/mm-1) [7] Carena, M.J., Bergman, G., Riveland, N., Eriksmoen, E. & Halvorson, M. 2009 Breeding maize for higher yield and quality under 5. Conclusion drought stress. Maydica 54, 287-296.

The analysis of maize yields in irrigated conditions [8] Khalili M., Naghavi M.R., Aboughadareh A.P., during four growing seasons have shown: Houshang N. R. (2013) Effects of Drought - Eastern Croatia (Osijek) area is affected by Stress on Yield and Yield Components in changes in climate and global environmental Maize cultivars (Zea mays L.). International conditions in which during dry and average Journal of Agronomy and Plant Production. growing seasons irrigation scheduling could be Vol., 4 (4), 809-812. recommended as the efficient management measure to improve water use efficiency and [9] Josipović M., Kovačević V., Šoštarić J., Plavšić irrigation water use efficiency, H., Marković M. (2012.): Irrigation and - Accurate irrigation scheduling based upon nitrogen fertilization needs for maize in Osijek- electrical resistance blocks is useful in improved Baranja County. Növénytermelés 61 (2): 45- water use efficiency. 48. - Water use efficiency as well as irrigation water use efficiency is not only crop and irrigation system [10] Šoštarić J., Marković M., Šimunović I., dependent but also weather and soil conditions. Josipović M. (2012.): Irrigation – wish or necessity. Proceedings of 4th International 6. References Scientific and Expert Conference of the International TEAM Society. 17 – 19 October, [1] Brouwer C., Prins K., Heibloem M. (1989) Slavonski Brod, Croatia. Vol. No. 1, 17-20. Irrigation water management: Irrigation scheduling. Training manual No. 4, FAO, [11] Hanson B., Peteres D., Orloff S. (2000) Rome. Effectiveness of tensiometers and electrical resistance sensors varies with soil conditions. [2] Petošić D., Kovačević V., Mustać I., Filipović V., California agriculture 54 (3) 47-50. Dujlović D. (2011) Impact of agriculture on [12] Irmak S., Payero J., VanDeWalle B., Rees J., leachate quality in the area of the amelioration Zoubek G. (2014) Principles and Operation canal for irrigation of the Biđ-bosut field. Characteristics of Watermark Granular Matrix Croatian Waters, 78:241-250. Sensors to Measure Soil Water Status and its Practical Applications for Irrigation [3] Riley W.J., Ortiz-Monasterio I., Matson P.A. Managements in Various Soil Textures. (2001): Nitrogen leaching and soil nitrate, [13]Marko Josipović, Hrvoje Plavšić, Ivan Brkić, nitrite and ammonium levels under irrigated Rezica Sudar, Monika Marković (2010): wheat in Norden Mexico. Nutrient Cycling in Irrigation, nitrogen fertilization and genotype Agroecosystems, 61:223-236. impacts on yield and quality of maize grain. Növénytermelés,59 (3) 255-258. [4] Timmons D.R., Dylla A.S. (1981): Nitrogen [14] Huang, R., Birch, J., George, D. L. 2006. Leaching as Influenced by Nitrogen Water use efficiency in maize production – the Management and Supplemental Irrigation challenge and improvement strategies. Maize Level. Journal of Environmental Quality, association of Austria. 6th Triennial 10:421-426. Conference, 2006. [15]Howell, T. A. 2003. Encyclopaedia of Water Science. pp. 467 - 472. [5] Gehl R. J., Schmidt J. P., Stone L. R., Schlegel [16] Blümling, B., Yang, H., Pahl-Wostl, C. 2011. A. J., Clark G. A. (2005) In Situ Proposal for the integration of irrigation Measurements of Nitrate Leaching Implicate efficiency and agricultural water productivity. Poor Nitrogen and Irrigation Management on Options méditerranéennes. Series B, 57:263- Sandy Soils. J. Environ. Qual., vol. 34: 2243- 280. 2254. [17] Takac J., Nejedlik P., Siska B. (2008): Irrigation water use efficiency. Adagio, Cecilia, [6] Blum, A. 2005 Drought resistance, water-use Cost734 Workshop, Jois, AT, Oct. 6-8., 2008. efficiency, and yield potential-are they [18] Terry A. Howell (2003) Irrigation Efficiency. compatible, dissonant, or mutually exclusive? Encyclopedia of Water Science 462-467. Australian Journal of Agricultural Research 56, 1159-1168.

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