[Effect of soil moisture content on fertilizer use efficiency and barley productivity in rainfed regions]
1988
Mohamad, S. (ACSAD, Damascus (Syria))
Chemical fertilizers represent one of the important factors in the production of wheat and barley in the rainfed regions. Their importance is dependent on the amount and distribution of rainfall, soil fertility level and the dominant crop rotation. Because of the great interaction between these factors, this study was conducted under different environmental conditions, using different levels of fertilizers in Syria and Jordan during a period of several years. The aim of the study was to determine: 1. relationship between soil fertility level and fertilizer use; 2. relationship between soil moisture balance and average rainfall; 3. relationship between soil moisture level and fertilizer use efficiency. The data obtained from this study have confirmed some scientific facts, which can be summarized as follows. Absolute relationship between soil available phosphorus and crop response (negative relationship); absolute relationship between soil moisture content and N use efficiency, particularly during the late stage of growth (netgative relationship). Efficiency of rainfall vis-a-vis the productivities of crops is dependent on rainfall distribution rather than amount of rainfall. Fallowing increase the soil profile content of reserve moisture for coming crops only in the wet seasons and not in the dry seasons
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