Wednesday, November 15, 2006 - 10:30 AM

Limited Irrigation of Four No-Till Summer Crops.

Alan Schlegel, Southwest Res. Ext. Center, Route 1, Box 148, Tribune, KS 67879, Loyd Stone, Agronomy Dept, KSU, 2004 Throckmorton, Manhattan, KS 66506-5501, and Troy Dumler, KSU-Southwest Area Extension, 4500 East Mary, Garden City, KS 67846.

A study was initiated under sprinkler irrigation at the Kansas State University, Southwest Research-Extension Center near Tribune, KS in the spring of 2001 to determine the impact of limited irrigation (125, 250, and 375 mm annually) on crop yield, water use, and profitability of four summer crops (corn, grain sorghum, soybean, and sunflower).  All crops were grown no-till.  Irrigations were scheduled to supply water at the most critical stress periods for the specific crops and limited to 38 mm/week.  An economic analysis determined optimal water allocations.  Because of changes in growing conditions, the most profitable crop changed from year-to-year so that there was not a single best crop.  Growing different crops when irrigation is limited can reduce risk and increase profitability.  .Averaged across the past 5-years, corn has been the most profitable crop at higher irrigation amounts while soybean has been the most profitable crop at the lowest irrigation amount.