A test of the suitability of subsurface drip irrigation (SDI) for alfalfa (Medicago sativa L) compared to a sprinkler, was conducted on a Kansas producer's field where the soil is loam. The treatments included drip tape spacing of 60, 40, and 30 inches placed at depths of 18 and 12 inches. A nearby plot irrigated by a center pivot sprinkler was seeded to alfalfa and used for comparison. Seedling emergence and yield were adversely affected at 60 inch spacing, while the depth of placement of drip tapes (18 and 12 inches) showed no effect on yield. The site served for education and allowed comparison between SDI tape spacing and center pivot system.

Many of the irrigation systems today in the U.S. Central Great Plains no longer have the capacity to match peak irrigation needs during the summer and must rely on soil water reserves to buffer the crop from water stress. Considerable research was conducted on preseason irrigation in the U.S. Great Plains region during the 1980s and 1990s. In general, the conclusions were that in-season irrigation was more beneficial than preseason irrigation and that preseason irrigation was often not warranted. The objective of this study was to determine whether preseason irrigation would be profitable with today's lower-capacity groundwater wells at different levels of corn plant density. A field study was conducted at the Kansas State University Southwest Research-Extension Center near Tribune, Kansas, from 2006to 2009 The study was a factorial design of preseason irrigation (0 and 75 mm), irrigation capacities (2.5, 3.8, and 5.0 mm d -1 ), and plant density (56,000, 68,000, and 80,000 plants ha -1 ). Preseason irrigation increased grain yields an average of 1.0 Mg ha -1 . Grain yields were 28% greater when irrigation capacity was increased from 2.5 to 5.0 mm d -1 . Crop water productivity was not significantly affected by irrigation capacity or preseason irrigation. Preseason irrigation was profitable at all irrigation capacities, although only slightly profitable at the highest irrigation capacity. Therefore, it may not be prudent to preseason irrigate with irrigation capacities of 5.0 mm d -1 or greater so that the water can be conserved for later use. At irrigation capacities of 2.5 and 3.8 mm d -1 , a seeding rate of 68,000 seeds ha -1 was generally more profitable than lower or higher seeding rates. A higher seeding rate (80,000 seeds ha -1 ) increased profitability when irrigation capacity was increased to 5.0 mm d -1 .

This study examines the economic potential of producing a wheat (Triticum aesitivum) and grain sorghum (Sorghum bicolor (L.) Moench) rotation with three different tillage strategies (conventional, reduced, and no tillage) compared with the Conservation Reserve Program (CRP) in a semiarid region. This research uses enterprise budgeting and stochastic efficiency with respect to a function to determine the preferred management strategies under various risk preferences. Yields, input rates, and field operations from an experimental field in western Kansas are used to calculate net returns for each tillage strategy. Although net returns to crop production using reduced tillage and no‐tillage strategies with average crop prices for January 2007 through December 2008 are higher than CRP payments, risk analysis indicates that CRP would be the preferred strategy for more risk‐averse managers. When average crop prices for January 2006 through December 2008 are used, CRP payments are higher than returns from crop production. Based on this analysis, only individuals who are risk‐neutral or slightly risk‐averse would prefer crop production to continue CRP enrollment in this region unless commodity prices reach the historically high levels of late 2007 and early 2008 and remain there.