266-1 Monitoring Soil Water Status Under Different Irrigation Regimes In North Central Kansas Soybean Cropping Systems.



Tuesday, October 18, 2011: 9:00 AM
Henry Gonzalez Convention Center, Room 213B, Concourse Level

Randall Nelson, Department of Agronomy, Kansas State University, Courtland, KS and Jessica Torrion, P. O. Box 830915, University of Nebraska - Lincoln, Lincoln, NE
Increasing applied irrigation efficiency is essential for maximizing soybean yields in irrigated cropping systems.  A study was initiated in 2011 near Scandia, KS to determine the effect of various irrigation rates and application timings on soil water and soybean yields in North Central KS. Soybean cultivar NK31-L7 (MG 3.7) was planted on 17 May. Three irrigation timing treatments were evaluated: 1) full-season irrigation strategy, 2) deferring all irrigation to soybean growth stage R3 (begin-pod), and 3) irrigation timing based on actual soil water depletion. The first two treatments followed the SoyWater irrigation system simulated soil water depletion at 50%, whereas the irrigation trigger used for the third treatment was 50% measured depletion prior to growth stage R3 and 35% depletion between R3 and R6. Three different irrigation amounts of 17, 24, and 32 mm were applied within each treatment to determine the interaction between irrigation rate and timing.  Soil Water was measured weekly by neutron probe attenuation to measure the actual soil water amounts with irrigation rate and timing. Plant height and number of nodes were measured on a weekly basis. Yield data were collected and water productivity (yield per water applied) was evaluated. 
See more from this Division: S06 Soil & Water Management & Conservation
See more from this Session: Management, Methods and Models for Efficient Use of Water and Nutrients: I