Impact of Grazing on Dryland Cropping Systems.
(S06-walker993192-poster)
Authors:
C.B. Walker* - Colorado State University F.B. Peairs - Colorado State University D.J. Poss - Colorado State University
Abstract:
Central Great Plains farmers face economic pressure to increase profit or go out of business. Insect control costs, particularly for Russian wheat aphid [Diuraphis noxia (Mordvilko)] remain a challenge in the modern diverse cropping systems that are now possible in our traditional wheat-fallow area. Winter wheat grazing is recognized as an effective Russian wheat aphid control practice. Our southeastern CO study site is one of six where we use a systems approach for insect pest management. Wheat-fallow is compared with wheat-sorghum-fallow at this site, which was established in 1997, in replicated strips across a 26 ha area. Wheat is grown as both a forage and a grain crop. Grazing the growing wheat and the sorghum aftermath is a treatment in our study. The first cattle grazing treatment occurred in spring 1998. Even though additional N fertilizer was applied, grazing reduced 1998 wheat yields by 375 kg ha-1 . The first grazing treatment continued to impact yields in subsequent years. Wheat yields were reduced by 160 kg ha-1 and 60 kg ha-1 in the 2nd and 3rd year following grazing, respectively.
Sorghum yields were reduced by 625 kg ha-1 in 1998 and by 475 kg ha-1 in 1999. Spring grazing of growing wheat and sorghum aftermath decreased subsequent grain yields, which was apparently due to soil compaction by cattle traffic.
Speaker Information: Cynthia Walker, Colorado State University, 1001 S. Main St., Lamar, CO 81052;
Phone: 7193367734; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 2:00 PM-4:00 PM Presentation Start: 2:00 PM (Poster Board Number: 1506)
