Soil Wetting Pattern of Drip Irrigated Maize as influenced by Deficit Irrigation and Discharge Rate

In water-scarce regions, improving water use efficiency of crops can be obtained if water and nutrients are properly applied. Under optimum management, drip irrigation systems allow a large degree of water savings by accurate application of irrigation amounts according to crop water requirements. Knowing the dimensions of soil wetting pattern under emitters are important for proper design of drip irrigation systems. The size of the wetted soil volume depends on the emitter discharge rate and the amount of irrigation water applied in each irrigation event. In the present study a field experiment has been conducted to determine the effects of discharge rate and deficit irrigation on the wetting pattern of the loam soil. Irrigation regimes included supplying 100%, 80% and 60% of crop water requirement. The emitters discharge rate was 0.7 lit/hr with the space of 20 cm and 1.3 lit/hr with 30 cm spacing between emitters. In order to monitor the soil wetting pattern, two profile probe’s access tubes were installed at 0, 15 cm lateral distance from the dripper line. The profile probe readings were recorded four hour after each irrigation event at 10, 20, 30, 40, 60 and 100 cm depth from the soil surface. The results showed that with application of the same amount of water to the soil, horizontal water movement in high discharge rate treatments was more than low discharge rate. Also, the vertical water movement was higher than the lateral movement in 0.7 lit/hr emitters as compared to 1.3 lit/hr.

کلیدواژه ها:

Soil Wetting Pattern ، Discharge Rate ، Deficit Irrigation ، Drip Irrigation ، Profile Probe