Impact of Driver Accuracy on Corn and Grain Sorghum Yields in Sub-surface Drip Irrigation

Abstract

Water availability from the Ogallala Aquifer is declining in the Oklahoma Panhandle, resulting in dwindling pumping capacities, and the need for water use efficiency. Subsurface drip irrigation (SDI) is a more efficient irrigation system that could be adopted by producers in this region if various management related questions could be addressed. One such question is how crop row placement will impact crop performance, irrigation water use efficiency and yield under SDI. Therefore, a study was established at the Oklahoma Panhandle Research and Extension Center in which drip tape is buried on 152.4 cm rows, allowing two crop rows planted on 76.2 cm to be irrigated with one tape. Corn and Sorghum rows will be offset from equidistance from the drip tape by 0, 8, 15, 23, and 38 cm. This resulted in 5 treatments with 4 replicates. A GPS system will be used to place rows at the offsets mentioned above. For each crop this treatment structure will be imposed on 3 irrigation regimes. Irrigation will be applied to replace 100% of evapotranspiration as determined by the Mesonet irrigation program as well as 75% and 50% of this rate. This project found that offset did not impact sorghum yield. Also, no significant impact on corn grain yield was observed, however, at the 50% irrigation regime a 10% reduction in average yield was observed. This data suggests that SDI can be successful regardless of access to high precision guidance systems.