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Farzin Parchami-Araghi; Fariborz Abbasi; Keramat Akhavan
Abstract
In this study, the seasonal applied water and physical and economic water productivity of soybean were evaluated through monitoring 37 farmers’ fields (with furrow/border irrigation systems) in Moghan Plain, Ardabil Province, Iran, during the 2020-21 growing season. The net soybean water requirement ...
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In this study, the seasonal applied water and physical and economic water productivity of soybean were evaluated through monitoring 37 farmers’ fields (with furrow/border irrigation systems) in Moghan Plain, Ardabil Province, Iran, during the 2020-21 growing season. The net soybean water requirement during that growing season and its 10-year mean value ranged from 431-691 mm and 442-671 mm with a mean of 542 and 543 mm, respectively. The mean seasonal total applied water (irrigation + effective precipitation) and the grain yield were 6554 m3 ha-1 and 2.90 ton ha-1, ranging from 5005-10009 m3 ha-1 and 2.05-4.12 ton ha-1, respectively. The mean seasonal total applied water for spring soybean (7906 m3 ha-1) was significantly (P < 0.01) higher than its corresponding value for summer soybean (6390 m3 ha-1). Total water productivity (WPI+Pe) and economic water productivity (WP$) ranged from 0.18 to 0.30 kg m-3 and 15.21 ´ 103 to 62.40 ´ 103 Rials m-3 with a mean of 0.24 kg m-3 and 33.19 ´ 103 Rials m-3, respectively. In most of the studied farms (70% of total cases), the grain yield was higher than the minimum expected threshold for irrigated soybean (2.5 ton ha-1). The results indicated that reasonable levels of grain yield and water productivity indices can be achieved by applying five and three irrigations for spring and summer soybean, respectively. The mean water application efficiency over soybean growth stages in the studied fields ranged between 50-82%.
Fahimeh Khadempour; Hossein Khozeymehnezhad; mahdi amirabadizadeh
Abstract
Climate change affects the hydrological processes through changes in temperature, precipitation, and other climate variables. One of the most important consequences of climate change is its impact on agricultural water consumption, which can seriously address water resources management. The purpose of ...
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Climate change affects the hydrological processes through changes in temperature, precipitation, and other climate variables. One of the most important consequences of climate change is its impact on agricultural water consumption, which can seriously address water resources management. The purpose of this study was to investigate the effects of climate change on daily evapotranspirationin different climates across Iran. For this purpose, the minimum, and maximum temperature, as well as precipitation, and sunshine hours were simulated for the period 2016-2036 on the A1B, A2 and B1a scenarios using the HadCM3 general circulation model and weather generator (LARS-WG 5.5) on daily time scale. The results indicated increase in temperature and evapotranspiration and decrease in precipitation in different climates. In another section of this study, by comparing the empirical equations, it was concluded that Hargreaves method with high R2, fair NS, and lower values of RMSE and MAE compared to other methods, can be an appropriate alternative for the FAO Penman-Monteith method on daily scale. For example, the results for Birjand station were R2 = 0.59, NS = 0.53, RMSE 6.84 and MAE = 6.01. Finally, Hargreaves- Samani and the Makkink methods had the least accuracy in estimating the reference evapotranspiration. Therefore, Hargreaves method can be selected as the best alternative method for estimating the reference evapotranspiration on a daily basis.