Effects of water stress on evapotranspiration of soybean
Abstract
Based on the results of observations, it was specified that when decreasing soil moisture there is a disproportionate decrease in the average daily evapotranspiration (ET). Thus, in the range of soil moisture of 94-80% minimum moisture-holding capacity (MMHC) ET was 9,76 mm a day, and in the range of 70-62% MMHC - its value decreased by 3 times. When the soil moisture reached 58,5% MMHC, the value of ET did not exceed 0,5 mm a day, which is 20 times less than the initial one. It was determined that the decrease in soil moisture by 10% in the range of 90 - 70% MMHC occurs during 3 days, and from 70 to 60% MMHC and from 60 to 58% MMHC - during 8 days. When soil moisture is 70% MMHC and below, the actual evapotranspiration is less than ETo that proves the effect of water stress on soybeans ET. When calculating water stress coefficient (Ks), a mathematical model based on the dependence of Ks on soil moisture as a percentage of MMHC was obtained. The average absolute percentage error (MAPE) is 8,6%, which corresponds to the high accuracy of the obtained dependence. In the range of soil moisture from 58 to 80% MMHC, the water stress coefficient is calculated by the formula Ks =-0.0011·FC²+0.1925·FC-7,4541. When having soil moisture as 80% MMHC and above, Ks = 1. A comprehensive comparative assessment of existing methods for calculating waster stress coefficient Ks was taken and it was found out that the actual values of Ks when having soil moisture as 80-70 and 60-65% MMHC by 8-14 % and 72-32 %, respectively, less than Ks FAO 56, and by 35-40 % larger than those determined by Saxton method. It was proved the need of taking into account the reduction in evapotranspiration when calculating water balance under water stress of plants. The calculation of evapotranspiration (ETs) by the Penman-Monteith method, without taking into account the water stress coefficient, showed that the value of the actual and calculated water balance coincides only when soil moisture does not exceed 62% MMHC. With a further decrease in soil moisture, the estimated soil moisture was 20% less than the actual, which led to the errors in determining soil moisture after irrigation, because its actual value was almost 100% MMHC, and the estimated one was only 60% MMHC. It was proved that the determination of water balance by calculation methods without taking into account the water stress coefficient leads to significant errors.
References
2. Saxton, K.E., Rawls, W.J., Romberger, J.S., & Papendick, R.I. (1986). Estimating generalized soil-water characteristics from texture. Soil Science of America Journal, 50(4), 1031-1036. DOI: 10.2136/sssaj1986.03615995005000040039x
3. Vivoni, E.R., Moreno, H.A., & Mascaro, G.I. et al. (2008). Observed relation between evapotranspiration and soil moisture in the North American monsoon region. Geophysical Research Letters, 35(22), 22403. DOI: 10.1029/2008GL036001
4. Kozyreva, L.V., Sitdikova, Yu.R., Yefimov, A.Ye., & Dobrokhotov, A.V. (2013). Metodika otsenki biologicheskogo vodopotrebleniya posevov dlya resheniya zadach upravleniya vodnym rezhimom [Methodology for assessing the biological water consumption of crops for solving problems of water management]. Agrofizika, 4(12), 12-19. [in Russian].
5. Shumova, N.A. (2018). Otsenka i analiz ispareniya, transpiratsii i zapasov vody v pochve poley yarovoy pshenitsy za bezmoroznyy period v razlichnyye po vodnosti gody [Assessment and analysis of evaporation, transpiration and water reserves in the soil of spring wheat fields for a frost-free period in years of different water content]. Ekosistemy: Ekologiya i Dinamika, 2(2), 65-88. DOI: 10.24411/ 2542-2006-2018-10009 [in Russian].
6. Poluektov, R.A, Kumakov, V.A., & Vasilenko, G.V. (1997). Modelirovaniye transpiratsii posevov selskokhozyaystvennykh rasteniy [Modeling of transpiration of crops of agricultural plants]. Fiziologiya rasteniy, 44(1), 68-73. [in Russian].
7. Evaporation, evapotranspiration and soil moisture. (2008). The Guide to Hydrological Practices. Vol. I Hydrology – From Measurement to Hydrological Information (WMO No.168). A publication of the Commission for Hydrology.
8. Shein, E.V. (2005). Kurs fiziki pochv [Soil physics course]. Moscow: Izd-vo MGU. [in Russian].
9. Jamieson, P.D., Francis, G.S., Wilson, D.R., & Martin R.J. (1995). Effects of water deficits on evapotranspiration from barley. Agricultural and Forest Meteorology, 76, 41-58 DOI: 10.1016/0168-1923(94)02214-5
10. Saeedinia, M., Hosseinian, S.H., & Beiranvand, F. (2017). The Effect of Water Stress on Evapotranspiration and Morphological Characteristics of Satureja Hortensis. Iranian Journal of Soil and Water Research, 50(8), 2063-2072. DOI: 10.22059/IJSWR.2019.276349.668131
11. Hamayunova, V.V., Pysarenko, P.V., Suzdal, O.S., & Kazano, O.O. (2010). Serednodobove vyparovuvannya ta sumarne vodospozhyvannya soyi zalezhno vid rezhymu zroshennya, fonu zhyvlennya ta sortu pry vyroshchuvanni na Pivdni Ukrayiny [Average daily evaporation and total water consumption of soybeans depending on the irrigation regime, feeding background and variety when grown in the South of Ukraine]. Zroshuvane zemlerobstvo, 53, 11-18. [in Ukrainian].
12. Vasyuta, V.V., & Zhuravlov, O.V. (2009) Vodospozhyvannya tsybuli ripchastoyi na kraplynnomu zroshenni v pivdennomu rehioni Ukrayiny [Water consumption of onion on drip irrigation in the southern region of Ukraine]. Zroshuvane zemlerobstvo, 52, 10-15. [in Ukrainian].
13. Kokovikhin, S.V., Pysarenko, P.V., Prysyazhnyy, Yu.I., & Pilyarska, O.O. (2011). Vplyv umov volohozabezpechenosti, fonu mineralnoho zhyvlennya ta hustoty stoyannya roslyn na urozhaynist dilyanok hibrydyzatsiyi kukurudzy v umovakh zroshennya [Influence of moisture supply conditions, mineral nutrition background and plant density on the yield of maize hybridization plots under irrigation conditions]. Zroshuvane zemlerobstvo, 56, 20-25. [in Ukrainian].
14. Wenhui, Zhao, Leizhen, Liu, & Qiu, Shen et al. (2020). Effects of Water Stress on Photosynthesis, Yield, and Water Use Efficiency in Winter Wheat. Water, 12(8), 2127. DOI: 10.3390/w12082127
15. Guswa, A., Celia, M., & Rodriguez-Iturbe, I. (2002). Models of soil moisture dynamics in ecohydrology: A comparative study. Water Resources Research, 38(9), 1166. DOI: 10.1029/2001WR000826
16. Reinder, A., Feddes, Holger Hoff, & Michael Bruen et al. (2001) Modeling root water uptake in hydrological models and climate models. Bulletin of the American Meteorological Society, 82, 2797– 2810. DOI: 10.1175/1520-0477(2001)082<27972810:
17. Shirley A., Kurc, & Eric E., Small. (2004). Dynamics of evapotranspiration in semiarid grassland and shrubland ecosystems during the summer monsoon season, central New Mexico. Water Resources Research, 40, W09305. DOI: 10.1029/2004WR003068
18. Posivni ploshchi silskohospodarskykh kultur za yikh vydamy u 2018 rotsi [Sown areas of agricultural crops by their types in 2018]. Derzhavna sluzhba statystyky Ukrayiny. Retrieved from: http://www.ukrstat.gov.ua [in Ukrainian].
19. Romashchenko, M., Shatkowski, A., & Zhuravlev, O. (2016). Features of application of the «Penman - Monteith» method for conditions of a drip irrigation of the Steppe of Ukraine (on example of grain corn). Journal of Water and Land Development, 31, 123-127. DOI: 10.1515/jwld-2016-0043.
20. Allen, R.G., Pereira, L.S., Raes, D.A, & Smith, M.I. (1998). Crop evapotranspiration – Guidelines for computing crop water requirements. FAO Irrigation and Drainage Paper No. 56. Rome: FAO. Retrieved from: http://www.fao.org/3/x0490e/x0490e00.htm
21. Goryanskiy, M.M. (1970). Metodika polevykh opytov na oroshayemykh zemlyakh [Methodology of field experiments on irrigated lands]. Kiev: Urozhai. [in Russian].
22. Grunty. Metody laboratornoho vyznachennya fizychnykh vlastyvostey [Soils. Methods of laboratory determination of physical properties]. (2010). DSTU B V.2.1-17:2009. Natsionalnyi standart Ukrayiny. Kyyiv: Minrehionbud Ukrayiny. [in Ukrainian].
23. Shatkovskyi, A.P., Romashchenko, M.I., & Vasyuta, V.V. et al. (2020). Evaluation of the «Penman–Monteith» model for determination of soybeans evapotranspiration in irrigated conditions of the Steppe of Ukraine. Modern Phytomorphology, 14, 111-113. DOI: 10.5281/zenodo.4449887
24. Brandes, D., Wilcox, D. (1971). Evapotranspiration and soil moisture dynamics on a semiarid ponderosa pine hillslope. Journal of the American Water Resources Association, 36 (5), 965-974. DOI: 10.1111/j.1752-1688.2000.tb05702.x
25. Budyko, M.I. (1971). Klimat i zhizn [Climate and life]. Leningrad: Gidrometeoizdat. [in Russian].
26. Shcherbakov, M.V., Brebels, A.A., & Shcherbakova, N.L. et al. (2013). A Survey of Forecast Error Measures. World Applied Sciences Journal, 171-176.
DOI: 10.5829/idosi.wasj.2013.24.itmies.8003
