SUPPRESSION OF IRRIGATION WATER DEFICIT STRESS AFFECTING SOYBEAN PRODUCTION

Drought phenomena have been frequenting in Egyptian history. So, the drought in the agricultural sector is a particularly important area to be examined. Therefore, a field experiment was carried out to evaluate three irrigation intervals as main factor [irrigation every 7, 9 and 11 days], soil addition of some conditioners [ control ( without), compost, zeolite and biochar ] as subplots and foliar application of magnesium silicate (sprayed or not) as sub-subplots on the performance and productivity of soybean plants as well as soil fertility after harvest. The main results showed that the soybean plants irrigated every 9 & 11 days had a low values of growth and production criteria compared to the soybean plants irrigated every 7 days which had the highest values of both growth criteria (e.g., plant height, fresh and dry weights and chlorophyll content) and yield components ( i.e., pod weight plant-1, seed weight plant-1, stover weight plant-1, 1000 seed weight, seed and stover yield). The addition of all studied soil amendments improved all studied growth and production criteria compared to the corresponding soybean plants grown on un amending soil, where the superior amendment was compost followed by zeolite and lately biochar conditioner. On the other hand, foliar application of magnesium silicate improved all studied growth and production criteria compared to the corresponding soybean plants grown without foliar application. Also, all studied soil amendments differed among them in their positive effect on soil fertility as well as their vital role in saving irrigation water.