DRIP IRRIGATION SYSTEM MANAGEMENT UNDER SALINITY CONDITIONS IN SANDY SOIL USING NUCLEAR TECHNIQUES

Abstract

A field experiment was carried out at the experimental farm of Nuclear Research Center in sandy soil with and without rice straw mulching under drip irrigation system during 2014/2015 winter season in Egypt to evaluate the effects of soil mulchingand irrigation water salinity on improving the yieldand water-use efficiency of wheat crop (Triticum aestivum L.) cv Masr 2 variety.Consequently, combating salinity stress via soil mulching was studied. Treatments of water salinity, i.e. fresh water (0.5 ds m-1), (6 dS m-1) and (8 dS m-1)were applied twice a weekly using a total amount of 440 mm during the growing cycle with and without rice straw mulching.Wheat irrigated with fresh water under non-mulching conditions resulted in higher yield (9.43 ardab fed-1 equal to 3366 kg.ha-1) than those of mulched one (9.04 ardab fed-1equal to 3227 kgha-1). Similarly, it was higher than those recorded with both water salinity levels. This holds true with either mulched or non-mulched plants. Under saline irrigation of 6 and 8 dS m-1,wheat yield and water use efficiency of mulched treatments was higher than the non-mulched ones. Nitrogen uptake by grainof wheat irrigated with fresh waterunder non-mulching treatments was much better than those of mulching treatments. Mulchingtreatmentsirrigated with 6 and 8 dSm-1were much better than non-mulched one. Nitrogen uptake byshoots in mulching treatments was much better than in non-mulching treatments.Nitrogen derived from fertilizer by grains was higher than those of shoot. It severely reduced by increasing water salinity levels as compared to fresh water treatment. Mulching treatment has a positive effect on combating salinity stress and in the same time improved the NUE comparing to the un-mulched soil.

Keywords: Drip irrigation,Mulching,15N application,Neutron scattering, Salinity management, Wheat.