Author
WESTFALL, D - COLORADO STATE UNIVERSITY | |
PETERSON, G - COLORADO STATE UNIVERSITY | |
PEAIRS, F - COLORADO STATE UNIVERSITY | |
Sherrod, Lucretia | |
Poss, David | |
SHAVER, T - COLORADO STATE UNIVERSITY | |
LARSON, K - COLORADO STATE UNIVERSITY | |
THOMPSON, D - COLORADO STATE UNIVERSITY | |
Ahuja, Lajpat | |
KOCH, M - COLORADO STATE UNIVERSITY | |
WALKER, C - COLORADO STATE UNIVERSITY |
Submitted to: Experiment Station Bulletins
Publication Type: Experiment Station Publication Acceptance Date: 10/20/2004 Publication Date: 11/1/2004 Citation: Westfall, D.G., Peterson, G.A., Peairs, F.B., Sherrod, L.A., Poss, D.J., Shaver, T., Larson, K., Thompson, D.L., Ahuja, L.R., Koch, M.D., Walker, C.B. 2004. Sustainable dryland agroecosystem management. Experiment Station Technical Bulletin TB04-05 Nov. 2004. Interpretive Summary: We established the Dryland Agroecosystem Project with No-till management in the fall of 1985 with 1986 being the first harvest year. Grain yields, stover yields, crop residue amounts, soil water measurements, and crop nutrient content have been reported annually in previously published technical bulletins. This publication covers the 2001 and 2002 grain yields, crop residue amounts, precipitation summaries, and N content of the crops and soil nitrate levels. Over the long term of the project, the 3- and 4-year cropping systems like wheat-corn-fallow or wheat-sorghum-sorghum-fallow increased annualized grain production by 74% compared to the 2-year wheat-fallow system during the first 12 years of the study. However, the last three years drought has been of major concern resulting in “near” crop failures some years and some complete crop failures in 2002. In years of limited rainfall, diversity is even more important by spreading the risk among different crops that my take advantage of rainfall in different times of the production year. The deletion of fallow however increases the risk of water deficit for the following crop. It is a management trade off between intensive cropping systems that result in increased return and production over the traditional tilled wheat-fallow system where risk due to moisture stress (drought) is less. Technical Abstract: We established the Dryland Agroecosystem Project with No-till management in the fall of 1985 with 1986 being the first harvest year. Grain yields, stover yields, crop residue amounts, soil water measurements, and crop nutrient content have been reported annually in previously published technical bulletins. This publication covers the 2001 and 2002 grain yields, crop residue amounts, precipitation summaries, and N content of the crops and soil nitrate levels. Over the long term of the project, the 3- and 4-year cropping systems like wheat-corn-fallow or wheat-sorghum-sorghum-fallow increased annualized grain production by 74% compared to the 2-year wheat-fallow system during the first 12 years of the study. However, the last three years drought has been of major concern resulting in “near” crop failures some years and some complete crop failures in 2002. In years of limited rainfall, diversity is even more important by spreading the risk among different crops that my take advantage of rainfall in different times of the production year. The deletion of fallow however increases the risk of water deficit for the following crop. It is a management trade off between intensive cropping systems that result in increased return and production over the traditional tilled wheat-fallow system where risk due to moisture stress (drought) is less. |