Submitted to: Crop Management at www.cropmanagement.org
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/18/2004
Publication Date: 4/16/2004
Citation: Parvin, D., Cummings, S., Dabney, S.M. 2004. No-till cotton yield response to a wheat cover crop in Mississippi. On-line. Crop Management. http://www.plantmanagementnetwork.org/pub/cm/research/2004/cover. Interpretive Summary: Farmers need cost-effective production methods that maintain or improve environmental quality. We conducted an on-farm experiment in which we measured input costs and yields from 9 pairs of 25 to 120 acre cotton fields in which one of each pair included a winter wheat cover crop. In all nine pairs, the field with a wheat cover crop yielded from 50 to 164 more cotton lint/acre, a statistically and economically significant amount. After accounting for all increased production costs, the net value of the average 110 pounds of lint per acre yield increase was $49 per acre. These results are valuable to producers because they were obtained under conditions that realistically reflect the time and equipment constraints associated with cotton harvest and establishment of a cover crop on commercial scale and indicate that the value of the yield increase of NT cotton to a wheat cover crop exceeds the cost of the establishing and managing that cover crop.
Technical Abstract: Farmers need cost-effective production methods that maintain or improve environmental quality. Experiment station research has shown that no-tillage (NT) cotton (Gossypium hirsutum L.) with a wheat (Triticum aestivum L.) cover crop can increase yields about 100 kg lint/ha compared to chisel/disk-tillage (CT) without a cover crop. However, growers hesitate to accept cover crop research results from small plot tests because such tests usually do not reflect the time and equipment constraints associated with cotton harvest and the establishment of the cover crop on their commercial cotton acreage. Therefore we conducted an on-farm paired-field experiment. Cooperating growers were asked to select pairs of 10 to 60 ha fields that were similar in terms of yield potential, soil type, slope, et al. Growers tended to select adjacent fields. Between 2000 and 2002, we measured input costs and yields from 9 pairs of cotton fields, with one of each pair including a winter wheat cover crop. In all nine pairs, the field with a wheat cover crop yielded more. The differences ranged from 55 to 180 and averaged 120 kg of lint/ha, a statistically and economically significant amount. At a cotton price of $1.32/kg lint, and wheat seed costing $0.26/kg, and considering additional costs of planting and harvesting, the net value of the average yield increase was $121/ha. The net value of the smallest yield response observed (55 kg of lint/ha) was $35 /ha. Thus, three years of research results in Yalobusha County, MS, (and Mid-South experiment station literature reviewed) indicate that the value of the yield increase of NT cotton to a wheat cover crop exceeds the cost of the wheat cover crop. Using the cover crop was profitable even without considering the benefits derived from reductions in soil and nutrient loss. However, more observations on the yield response on different soil types in other areas would be needed before the level of profitability of a wheat cover crop in NT cotton production could be stated generally.