EFFECT OF PREVIOUS CROP AND N- RATE ON PRODUCTIVITY AND ECONOMIC EVALUATION OF GROWNING BREAD WHEAT USING RAISED BED TECHNIQUE

This study was carried out at different locations (on farmers’ fields) in Sharqia Governorate, Egypt, during 2012/2013 season to find out the effect of previous crop (rice, cowpea, cotton and maize), planting methods (traditional and raised bed) and nitrogen fertilizer rate (120 and 180 kg N ha-1) on some wheat (var. Mesr 1) yield components, grain, straw and biological yields and NPK contents in grain and straw as well. Water applied and net return of growing wheat on raised bed, compared to confidential method (flat) were considered. The most important findings could be summarized as follows: Regardless the previous crop and the assessed N-rate, the yield attributes of spike No m-2, grain No spike-1, grain weight spike-1 and 1000 grain weight were higher under raised bed planting, comparable with traditional planting. In addition, grain, straw and biological yields exhibited the same trend. The abovementioned variables were higher as cowpea was the preceding crop. Regardless different locations, raised bed planting resulted in higher figures for the abovementioned variables even with lower N-rate e.g.120 kg N ha-1, comparing with traditional planting with supplying N at180 kg ha-1. Higher N, P and K uptake for grain and straw yields were attained due to raised bed planting, comparable with traditional planting, and the values were greater as cowpea was the previous crop with supplying N at 180 kg ha-1 rate. The applied irrigation water was varied from 3991 to 4513 m3 ha-1 under raised bed planting method at different locations, comparing with 5781 m3 ha-1 recorded with traditional planting. In general, the highest cost estimated is about 5695 LE with traditional planting method, whereas, the lowest cost estimated i.e. 5295 LE was recorded with raised bed planting receiving the lowest N rates. The highest net return (27961 LE) was achieved due to growing wheat crop, after cowpea crop, on raised bed with supplying N at 180 kg ha-1rate which. On the contrary, the lowest net return (15438 LE) was noticed with traditional planting method. On conclusion, it is advisable to grow wheat crop, after a legume crop, on raised bed, where higher figures of wheat grain yield and its N, P and K contents were obtained. In addition, saving irrigation water and conserving soil fertility as well as higher net economic return were with planting wheat on raised bed instead of the conventional method.