Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2005
Publication Date: 11/6/2005
Citation: Bergtold, J.S., Terra, J.A., Reeves, D.W., Shaw, J.N., Balkcom, K.S., Raper, R.L. 2005. Spatial variability in net returns for conservation tillage systems with alternative mixtures of high residue cover crops [abstract]. American Society of Agronomy Abstracts. Interpretive Summary: In order to conserve soil resources in the southeastern United States, many farmers have adopted conservation tillage systems to maintain profitability. A key part of this system is the use of winter cover crops to help protect the soil. To make sure that using cover crops is profitable, farmers should try to get as much biomass from the cover crops as possible to maximize benefits. This study examines the use of mixtures of winter cover crops that provide a large amount of biomass to determine if the use of these crops is profitable for the farmer. Findings show that cover crops can help reduce soil erosion and improve crop yields, thereby increasing farm profits. In years with low rainfall, they can help reduce the risk of lower crop yields and profits to the farmer.
Technical Abstract: Given that farmers are faced with uncertainties due to unpredictable factors when using a cover crop such as nutrient availability, weather and pests, farmers may be concerned about the risk of lowering net returns when using a cover crop. This concern grows as the cost of planting and managing the cover crop increases, which can be the case for alternative mixtures of high residue cover crops, such as black oat (Avena strigosa Shreb.) and rye (Secale cereale L.). Given that soil conditions and topography can differ significantly within a given field, spatial variability may be of interest to a farmer. If conservation tillage systems with cover crops can reduce spatial variability of crop yields, then it may help to reduce variability in net returns, lowering the risk associated of planting a cover crop. The purpose of this paper is to examine the profitability and spatial variability of net returns of conservation tillage systems with alternative high-residue cover crops. An experiment was conducted near Shorter, AL using a factorial arrangement of two management systems with six replications on a two-year corn (Zea mays L.) - cotton (Gossypium hirsutum L.) rotation with both phases of the rotation present each year from 2001 to 2003. The first management system was a conservation system with a mixture of white lupin (Lupinus albus L.), crimson clover (Trifolium Incarnatum L.), and fodder radish (Raphanus sativus L.) planted prior to corn; and a mixture of black oat and rye planted prior to cotton. The second management system was a conventional tillage system with no cover crop. Results indicate that the use of alternative mixtures of high-residue cover crops, while being more costly to plant than traditional cover crops, can increase crop yields and decrease the risk of obtaining lower crop yields and net returns in drought years.