Evaluation of sorghum sudangrass as a summer cover crop and marketable hay crop for organic, no-till production of fall cabbage
The development of organic and conservation tillage-based vegetable production systems will offer growers in the southeastern United States new economic opportunities and promote resource conservation. The purpose of this research project was to assess the impact of incorporating a summer crop that serves as both cover crop and marketable hay crop in an organic fall vegetable production system. Sorghum sudangrass [Sorghum bicolor (L.) Moench X S. sudanense (Piper) Staph] is commonly cultivated as a forage crop in the Southeast and has the potential to produce abundant biomass, suppress weeds, and decrease soil compaction as a summer cover crop. Field studies were conducted to determine the effects of sorghum sudangrass cutting frequency and biomass removal as hay on cover crop biomass production, weed suppression by cover crop residues, and cover crop re-growth in a subsequent cabbage (Brassica oleracea L. var. capitata) crop under conventional and no-till management. Field and greenhouse studies were undertaken to identify potential negative interactions between cover crop residues and cabbage transplants. Transplant dry weight and head weight of the indicator species, cabbage, were used to assess the impact of cover crop management and tillage system on crop growth and development. Results suggest that a sorghum sudangrass hay crop can be harvested without compromising weed suppressive qualities of the cover crop. In this study, however, the presence of sorghum sudangrass led to reductions in cabbage transplant growth and head weight. Sorghum sudangrass may not be suitable as a cover crop immediately prior to conventional or no-till fall vegetable production due to its propensity to re-grow and allelopathic potential.
Advisor:Jonathan Schultheis; Michael Wagger; Nancy Creamer
School:North Carolina State University
School Location:USA - North Carolina
Source Type:Master's Thesis
Date of Publication:04/13/2005