Effect of pulse drip irrigation and mulching systems on yield, quality traits and irrigation water use efficiency of soybean under sandy soil conditions

Abstract

Two field experiments were carried out during growing seasons 2010 and 2011, it executed in research farm of national research center in Nubaryia region, Egypt to study the effect of pulse drip irrigation and mulching systems for saving water, increasing and improving yield of soybean. The study factors were, pulse drip irrigation technology (adding of daily water requirements on 4 times, 8 times, 12 times compared with adding of daily water requirements on 1 time) and mulching systems (covering the soil with black plastic mulch “BPM”, rice straw mulch “RSM” and the control treatment was soil surface without mulch “WM”). The following parameters were studied to evaluate the effect of pulse drip irrigation and mulching systems: 1) Soil moisture distribution in root zone, 2) Growth characters of soybean plant, 3) Yield of soybean, 4) Irrigation water use efficiency of soybean “IWUE soybean”, and 5) Oil content and oil yield, 6) Protein content and protein yield, 7) Economical parameter. According to the economical view and the results of statistical analysis for effect of pulse drip irrigation and mulching systems on yield, quality traits and IWUE soybean indicated that, applying the irrigation requirements on 8 pulses/day with using BPM is the best conditions because under these conditions was occurred the highest value of yield, quality traits and IWUE soybean and there was significant deference between this case and other treatments. Where, pulse irrigation technique increase from water movement in horizontal direction than vertical direction hence improve from soil moisture distribution and wetted soil volume in root zone and using BPM decrease from evaporation process rate from soil surface hence decreasing of salts accumulation in addition to decreasing of weed growth in the root zone. All traits at AIR on 12 pulses/ day are decreased by increasing of pulses, this may be due to irrigation water was very small with every pulse at AIR on 12 pulses/day in addition increasing the total time of time-off, this mean, un-sufficient application for irrigation water to remove water stress in the root zone.