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ARS Home » Plains Area » Sidney, Montana » Northern Plains Agricultural Research Laboratory » Agricultural Systems Research » Research » Publications at this Location » Publication #213726
Title: Farming Systems Design: Methodologies for integrated Analyses of Farming Systems

Author
item Lenssen, Andrew
item Sainju, Upendra
item Caesar, Thecan
item Allen, Brett
item Lartey, Robert

Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/14/2007
Publication Date: 8/11/2007
Citation: Lenssen, A.W., Sainju, U.M., Caesar, T., Allen, B.L., Lartey, R.T. 2007. Farming Systems Design: Methodologies for integrated Analyses of Farming Systems. Proceedings of the European Society of Agronomy and American Society of Agronomy. Farming Systems Design Conference, Catania, Italy, September 10-12, 2007. 2:37-38.

Interpretive Summary: Available water, depleted soil quality, and weed competition are important constraints to crop production in the northern Great Plains. The traditional rotation in the region has been spring wheat with summer fallow, which is used to accrue additional soil moisture for the subsequent wheat crop. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water and inorganic nitrogen, decreasing the efficiency of fallow and increasing soil erosion. Chemical fallow and zero tillage systems improve soil water status for subsequent crops, allowing for increased cropping intensity and improved nutrient cycling and soil quality. However, zero tillage systems can result in greater weed problems. Multi-tactic, cultural management systems, including use of higher seeding rates, banded fertilizer applications, variation in planting dates, and greater crop stubble retention, can improve management of weeds. The objectives of the trial are to compare influences of rotation, tillage, and management system on crop yield, yield components and quality, water and nitrogen use and use efficiencies, soil quality, microbial diversity, carbon sequestration, and weed dynamics. After three years, the effects of rotation and management system are important for grain yield of spring wheat and pea. Wheat in 2-, 3-, and 4-year rotations has greater grain yield than continuous wheat. Pea in 3- and 4-year rotations has greater yield than pea produced in 2-year rotations. Hay production from barley is greater under zero- than conventional tillage, but for other crops, tillage system had less influence on productivity than management system or rotation. Ecological management reduced weed biomass at crop harvest. For wheat and pea, crop yield decreased with increasing weed biomass at harvest. Early results from this long-term study indicate that ecological management and diversified rotations improve spring wheat and pea yield, in part through increasing crop competitiveness with weeds.

Technical Abstract: Available water, depleted soil quality, and weed competition are important constraints to crop production in the northern Great Plains. The traditional rotation in the region has been spring wheat with summer fallow, which is used to accrue additional soil moisture for the subsequent wheat crop. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water and inorganic nitrogen, decreasing the efficiency of fallow and increasing soil erosion. Chemical fallow and zero tillage systems improve soil water status for subsequent crops, allowing for increased cropping intensity and improved nutrient cycling and soil quality. However, zero tillage systems can result in greater weed problems. Multi-tactic, cultural management systems, including use of higher seeding rates, banded fertilizer applications, variation in planting dates, and greater crop stubble retention, can improve management of weeds. We are conducting a long-term study investigating the influence of rotation, tillage and management system on crop yield, yield components and quality, water and nitrogen use and use efficiencies, soil quality, microbial diversity, carbon sequestration, and weed dynamics. Crop rotations are continuous spring wheat (SW), SW-pea, SW-barley for hay-pea, SW-barley for hay-corn-pea. Management systems are conventional and ecological. Tillage systems are conventional preplant tillage and zero-tillage. All phases of each rotation are present every year in four combinations of tillage and management systems. After three years, the main effects of rotation and management system are significant for grain yields of spring wheat and pea. Compared with continuous wheat, spring wheat yield increased when produced in a two-year rotation with pea, but additional yield was not gained by less frequent planting than ever other year. Pea yield was greater following barley hay or corn than spring wheat. Hay production of barley was greater under zero-than conventional tillage, but for other crops, tillage system had less influence on productivity than management system or rotation. Ecological management reduced weed biomass at harvest. Regression analyses of yield with weed biomass at harvest resulted in highly significant and negative relationships for wheat and pea, indicating that weed competition had a large impact on grain yield. Early results from this long-term study indicate that ecological management and diversified rotations improve spring wheat and pea yield, in part through increasing crop competitiveness with weeds.