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Mohammad Khaledi Alamdari; Abolfazl Majnooni Heris
Abstract
Annual and seasonal rainfall distributions are the main determinants of yield in rainfed conditions, of which seasonal rainfall is more important. Therefore, it is necessary to provide precipitation indicators that have a significant conceptual relation with crop performance fluctuations. ...
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Annual and seasonal rainfall distributions are the main determinants of yield in rainfed conditions, of which seasonal rainfall is more important. Therefore, it is necessary to provide precipitation indicators that have a significant conceptual relation with crop performance fluctuations. In the present study, the relation between rainfall uniformity indices and rainfed wheat yield in Tabriz plain was evaluated in 19-years period. Also, in order to examine the effect of precipitation more accurately, the Rain-Time Index [M1] [M2] (RTI) was used, which could indicate the effect of simultaneous changes of the two factors of rainfall time and rainfall amount on crop yield fluctuations. The results showed that the correlation between rainfed wheat yield and slope of uniformity line (ratio of cumulative precipitation per length of growing period) was significant at 1% level. However, there was no significant correlation between the uneven distribution index and yield. Also, according to the obtained results, the first effective rainfall event is the most effective rainfall event on the yield of rainfed wheat. It seems that the inadequacy of effective spring rainfall, which is one of the main reasons for the low yield of rainfed lands, prevented the explanation of the positive effect of late season rainfall on yield. Therefore, in order to evaluate the effect of intermittent precipitation and Rain-Time Index [M3] [M4] on yield more accurately, a single supplementary irrigation should be applied at the stage of grain filling and its effect on the studied indicators and yield should be investigated.
Naser Arya Azar; Abolfazl Maajnooni Heris
Abstract
For proper use of available water resources in agricultural sector, selection of suitable irrigation system is necessary to provide the crop water requirements. Correct choosing of irrigation system is an important step in optimal application of water and soil resources. Involvement of several influential ...
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For proper use of available water resources in agricultural sector, selection of suitable irrigation system is necessary to provide the crop water requirements. Correct choosing of irrigation system is an important step in optimal application of water and soil resources. Involvement of several influential factors in selection of appropriate irrigation system has made this a relatively complex issue. In this study, application of different irrigation systems were prioritized by climate, water, soil, field, irrigation efficiency, cultural, social and economic information using analytical network process method (ANP) in the Ajichay river basin. Based on the results of the selected criteria, water quantitative and qualitative, irrigation efficiency, and soil had the most effect on the best irrigation system selection with relative weights of 0.222, 0.221, and 0.1539, respectively. Also, the results of the sub-criteria scores showed that the sum of water sub-criteria was the highest, with final score of 0.26815, among the other sub-criteria scores. Finally, the results showed that, among surface irrigation systems, the basin system with a score of 0.15544, among sprinkler systems, the classic system with score of 0.10432, and among localized systems, trickle system with a score of 0.12754 had priority over other systems. Keywords: Suitable irrigation system, Basin irrigation, Classic sprinkler system, Trickle irrigation system