Impact of soybean conservation systems on bobwhite quail habitat and mortality.

Conservation-tillage systems on the Southeastern Coastal Plain now utilize practices such as minimum surface tillage, narrow row widths, and planting of herbicide-tolerant varieties. These systems can result in many economical, environmental, and ecological benefits, including providing a more suitable habitat for wildlife such as the northern bobwhite quail (Colinus virginianus). Our research objectives were to assess the possible ecological impacts of both an innovative soybean (Glycine max L. Merr) tillage system (no-till) and traditional soybean system (tilled) on quail habitat and preference. Variables measured were insect abundance, canopy closure and pen-raised quail habitat use. No-till soybean fields were found to have the greatest abundance of orthopteran (crickets/grasshoppers), arachnid (spiders), and coleopteran/hemipteran (centipedes/beetles) insects. Insect numbers were higher in the no-till system than in the tilled system, field borders, and forested areas. The tilled system generally had the second highest number of insects, followed by field borders and forested areas. Canopy closure as estimated by light transmittance through the canopy, was faster and more complete in the no-till system than the tilled system due to the narrower row width used with the no-till system. Pen-raised quail were found more frequently in the no-till system than the tilled system a majority of the time. Greater quail use of the tilled system only occurred at one field. Field borders and forested areas were used less than either tillage systems. Averaged over treatments and release days, the greatest cause of mortality was due to mammals. These results indicate that no-till systems are more beneficial to quail than traditional systems in terms of habitat quality. INTRODUCTION Methods used by farmers to produce agronomic crops have changed dramatically in recent years. Practices such as conservation tillage, use of narrow row widths, and herbicide-tolerant varieties enhance yields, as well as provide environment benefits. Planting using narrow row widths and the use of glyphosate-tolerant varieties can be a tremendous aid for controlling weeds in no-till systems where cultivation is not feasible. The ease of weed control and the potential environmental benefits from using glyphosate-tolerant varieties has resulted in a majority of South Carolina’s soybean acres being planted in these varieties. Because of the increased popularity, more information is needed about the benefits or problems that can occur when these practices are used collectively as one integrated soybean production system, especially with respect to impact on non-targeted species. For example, no-till systems utilizing narrow row widths and herbicide-tolerant varieties may influence the number and type of insects in a field due to the presence of plant residues, the rapid canopy closure that occurs with narrow row widths, and differences in weed species (compared to traditional tillage). These changes, in return, can affect quail which feed upon these insects. Information on the positive aspects of new technologies is needed due to the negative publicity these advances have received in recent years.