Submitted to: Annual Southern Conservation Tillage Conference for Sustainable Agriculture
Publication Type: Proceedings
Publication Acceptance Date: 5/20/2004
Publication Date: 6/8/2004
Citation: Robinson, S.J., Frederick, J.R., Bauer, P.J., Busscher, W.J. 2004. Producing winter wheat with conservation tillage on the southeastern coastal plain. In: 26th Southern Conservation Tillage Conference, June 8-9, 2004, Raleigh, NC. p. 181-189. 2004 CDROM. Available: http://www.ag.auburn.edu/nsdl/sctcsa/.
Technical Abstract: Producing winter wheat (Triticum aestivum L. em Thell) with conservation tillage has lagged behind most other major row crops on the southeastern Coastal Plain. Producer reluctance to use this practice has primarily been due to the lower wheat grain yields often obtained with conservation tillage. The objectives of our study were to (i) determine how conservation tillage affects winter wheat fertile tiller number per sq. ft., number of kernels per tiller, and/or individual kernel weight and (ii) examine how different management practices affect wheat grain-yield responses to conservation tillage. Three separate field studies were conducted to test treatments of surface and deep tillage (Studies I, II, and III), direction and timing of deep tillage (Study III), fall N fertility rate (Study III), and crop rotation (Study II). In Studies I and II, average grain yield of wheat grown with conservation tillage was 6% less than the average grain yield of wheat grown with traditional tillage (disking). Lower grain yields with conservation tillage were associated with fewer plants per sq. ft. after planting and fewer tillers per sq. ft. at harvest. Deep tillage, a higher fall N fertility rate, and crop rotation all increased the number of tillers per sq. ft. when the conservation tillage treatment was used, but usually not enough to compensate for its lower plant number per sq. ft. The timing and direction of deep tillage had little effect on wheat grain yield and tiller number. Results from these studies indicate that obtaining an adequate number of fertile tillers per sq. ft. is critical to the success of using conservation tillage for winter wheat production on the southeastern Coastal Plain.