Field assessment of soil moisture and crop yield distri- bution uniformities under sprinkler irrigation

摘要

The yield response of the crop is affected by the water within its root zone. Hence, the distribution of water within the soil is more important than its distribution on the soil surface. The present study aimed to evaluate the effects of water application uniformity on the soil moisture and alfalfa crop yield distribution uniformity in sprinkler irrigation system. The field experiments were conducted in an alfalfa field on three plots of 25 CHI 30 m. The average values of the uniformity coefficientsfor experimental plots throughout the irrigation events were estimated to vary between 72 and 85% for sprinkler water application and between 88 and 91% for soil moisture. The results reveal that soil water content uniformity is around 20% higher than sprinkler water uniformity. The findings demonstrate that soil moisture and alfalfa crop yield distribution uniformities have nearly values. Hence, it could be concluded that the influence of sprinkler water uniformity on the redistribution of sprinkler water in the soil may be the same of the crop yield. Thus, it seems that in arid and semi-arid regions, with a limited water resources, reduced water application uniformity and irrigation amount lead to increased crop water productivity. A reduction of up to 70% in sprinkler water uniformity can be recommended for this purpose.