Crop Yield as Affected by Uniformity of Sprinkler Irrigation System

The effect of sprinkler uniformity on crop yield is a concern for system designers because it is an important consideration in selection of target uniformity for conventional systems. However, there is few field data on this subject. Field experiments were therefore conducted to observe the spatial variations of water in the soil and to study the response of crop growth and yield to nonuniform water application during the irrigation season of winter wheat in north China. Christiansen uniformity coefficients (CUC) were used in this article to quantify the uniformity of sprinkler water above and below canopy, soil water content, plant height, LAI, and crop yield. The results demonstrated that CUCs for water storage in the soil were always greater than 90 % even though sprinkler uniformities varied from 57 % to 89 % during the irrigation season. Also, the uniformities of plant height, LAI, and crop yield were higher than those for water application and seem to be insensitive to spatial variation of applied water. The influence of sprinkler uniformity on crop yield is not as important as previous modeling. A reduced uniformity may not necessarily result in a lower yield