MANAGEMENT SYSTEMS FOR SOIL CONSERVATION AND SUSTAINABLE CROP PRODUCTIVITY

Authors: TRIPLETT, GLOVER - MAFES; Dabney, Seth; SPURLOCK, S - MISSISSIPPI STATE UNIV; REINSCHMIEDT, L - MISSISSIPPI STATE UNIV

Submitted to: Management of Landscapes Disturbed by Channel Incision Stabilization Rehabi
Publication Type: Proceedings
Publication Acceptance Date: 3/7/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Crop production with CT (conventional tillage) on sloping land may loose 15 to 20 tons of soil/acre/year. Soil loss reduces productivity potential and causes off-site siltation of streams and reservoirs. NT (no-tillage) can reduce soil loss by 95 to 99%, but has not been widely adopted in the Midsouth. In 1988, conservation tillage systems research was initiated on an upland area (Demonstration Erosion Control) watershed with slopes ranging from 2 to 6% for determining yield and profitability of alternative cropping management systems. Crops included cotton, soybean, wheat, grain sorghum, and later, corn. Yield levels varied with growing season rainfall, and both above- and below-average rainfall occurred during the study. NT cotton averaged 1.5 bales/A, while CT cotton averaged slightly more than 1/bale/A. At historic prices, returns for NT and CT cotton averaged $87/A and $54/A, respectively. NT corn averaged 125 bu/A while CT corn averaged 122 bu/A. Corn in both tillage systems returned more than $100/A at historic prices. Grain sorghum yields were 71 and 77 bu/A for CT and NT, respectively. Returns from sorghum were barely at the break-even level with several years having negative returns. Returns from a wheat-soybean doublecrop system were over $70/A at historic price levels. During the last two years, prices of commodities have increased by 20 to 30%. If commodity prices are maintained at current levels, an increase in crop production on upland sites should be expected. In that case, with CT systems will greatly increase off-site sediment movement. This research shows that farms in the DEC or similar watersheds could convert CRP land or pasture to row-crop production with NT without sacrificing yield or profit and without greatly increasing sediment yield

Technical Abstract: Profitable annual crop production is a function of commodity prices, yields, and production costs. In 1996, commodity prices were near historic highs and prices at these levels could lead to conversion of idle land to production of annual crops. If this occurs with CT (conventional tillage) systems, off-site sediment movement will greatly increase. Annual crop production with CT on upland, sloping sites can create a soil loss potential of 30 to 45 Mg per hectare per year (15 to 20 tons/acre/year). This reduces soil productivity potential and creates off-site siltation of streams and reservoirs. NT (no-till systems can reduce soil loss by 95 to 99%, but these systems have not been widely adopted in the Midsouth. In 1988, conservation tillage systems research was initiated on an upland site with slopes ranging from 2 to 6% in a study evaluating yield levels and profitability of alternative crop management systems. Crops in the DEC (Demonstration Erosion Control) watershed studies included cotton, soybean, wheat, grain sorghum, and, later, corn. Yield levels varied with growing season rainfall. Yield level of cotton grown under NT were greater than with CT. Yield levels of corn and sorghum were equal regardless of tillage system. The most profitable cropping systems were continuous corn and a wheat-soybean DC (doublecrop) - corn rotation. The most profitable cotton system was NT cotton planted into a killed wheat cover crop. This research shows that farms in the DEC or similar watersheds could convert CRP land, pasture, or idle areas to row-crop production with NT without sacrificing yield or profit and without increasing sediment yield to unacceptable levels