Water is considered one of the most critical input resources for sustainable development at crop production. Selecting suitable irrigation system is very important to get high crop production and overcome water shortage.A field experiment was carried out at Rice Mechanization Center (RMC), Meet El-Deepa, and Kafer El–Sheikh Governorate during summer season 2014/2015 for soybean. The main aim of this research is to study the effect of different drip irrigation treatments on the productivity of soybean crop and irrigation water use efficiency (IWUE) under clayey soil conditions. The field treatments were designed as a split plots experimental design. The main plots were operating pressure head levels of 6(P1), 5(P2), 4(P3), and 3 meter (P4).Sub-main plots were included continuous drip irrigation (C), two levels of pulse drip irrigation in 15 min on/15 min off (S1) and 20 min on/20min off (S2) with three replication. Furrow irrigation (Tf) was used as control treatment soybean productivity, irrigation water use efficiency IWUE, uniformity parameters, and some plant characteristics were conducted to evaluate the performance of irrigation system and operating pressures. The important results indicated that:
Pulsed drip irrigation achieved a good water distribution in clayey soil.
Soybean productivity was increased by the percentage of 24.9, 23.7, 19.3, 14.0, 1.2% comparing with (Tf) for P1S1, P1S2, P1C, P2S1, P2S2, respectively. Wherever, it was decreased by the percentage of 2.8, 3.6, 21.1, 26.5, 37.5, 47.7 % comparing with Tf for P2C, P3S1, P3S2, P3C, P4S1, P4S2, P4C, respectively.
The results showed that the highest values of IWUE and distribution uniformity were 0.54 kg/m3 at P1S1 treatment and 96.61% at 6m pressure operating head (P1).
Application of pulsed drip irrigation was more effective to improve the front wetting zone of clay soil.
In conclusion, pulse drip irrigation treatment of (15 min open/15 min close) and operating pressure head of 6m gave the best results.