Location: Agroecosystem Management ResearchTitle: Stover removal effects on seasonal soil water availability under full and deficit irrigation
|FERGUSON, RICHARD - University Of Nebraska|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2015
Publication Date: N/A
Technical Abstract: Removing corn (Zea mays L.) stover for livestock feed or bioenergy feedstock may impact water availability in the soil profile to support crop growth. The role of stover in affecting soil profile water availability will depend on annual rainfall inputs as well as irrigation level. To assess how residue management affects soil profile water availability during the crop growing season, soil moisture was measured continuously at 1, 2, 3, and 4 foot soil depths during a severe drought year (2012) and in an above average rainfall year (2014) in an irrigated, no-till continuous corn system in south central Nebraska, USA. Residue management included no stover removal (0% of non-grain aboveground biomass removed) or maximum removal (60% of non-grain aboveground biomass removed) under full irrigation or deficit irrigation (60% of full). Stover removal resulted in lower total soil water availability overall. During the drought year, grain yields were highest under full irrigation when stover was retained, and stover removal under full irrigation reduced both available soil water and grain yields to levels measured under deficit irrigation. In contrast, during the high rainfall year, grain yields under full irrigation were lower when stover was retained compared to removed, despite greater total soil water availability with stover retention. Although stover removal may exacerbate yield losses during drought years even under full irrigation, small but significant yield increases with stover removal during more abundant rainfall years may help stabilize long-term grain yields from irrigated continuous corn systems incorporating stover harvesting practices.