|MC KERN, A|
Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2007
Publication Date: 4/1/2008
Citation: Delate, K., Cambardella, C.A., Mc Kern, A.C. 2008. Effects of organic fertilization and cover crops on organic pepper production. HortTechnology. 18(2):215-226.
Interpretive Summary: A growing consumer preference for organically grown fruits and vegetables has encouraged many producers to investigate organic methods. Organic management is an attractive alternative to conventional cultivation methods for producers interested in gaining premium prices for their crops while lowering input costs. This study evaluates several combinations of fertility management practices for the production of organically grown bell peppers in southeast Iowa, including cover crops and composted animal manure. Impacts of organic management options on pepper yield and quality were consistent, except when cover crops weren’t adequately incorporated into the soil. The results provide guidance to producers, researchers, and other agricultural professionals for the development of soil building protocols in certified organic vegetable systems.
Technical Abstract: The requirement for certified organic vegetable producers to implement a soil-building plan has led to the development of soil fertility systems based on combinations of organic fertilizers and cover crops. In order to determine optimal soil fertility combinations, conventional and organic bell pepper (Capsicum annuum L.) production was evaluated from 2001 to 2003 in Iowa, comparing combinations of two synthetic fertilizer and three compost-based organic fertilizers, and two cover crop treatments of hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) in either a strip-tilled or fully incorporated cover crop system. Conventional and organic pepper growth and yields were similar in the 112 kg ha-1 N synthetic fertilizer conventional treatments and the 56 or 112 kg ha-1 N compost-based fertilizer organic treatments. When strip-tilled cover crop plots were not fertilized, strip-tilled pepper yields were lower than organic fertilization alone and the incorporated cover crop treatment. Increased incidence of disease was also detected in strip-tilled plots. Animal-based and cover crop-based fertilization was effective in increasing soil organic matter and nitrogen in all organic treatments. Crop response corresponded with soil fertility results, where complete incorporation of the hairy vetch/rye cover crop increased soil inorganic N to a greater extent compared to strip-tillage. While strip-tillage of vegetables into cover crops can help mitigate soil erosion and aid in weed management, competition between vegetable and cover crop re-growth, inadequate N contribution, potential cooling of soil, and the requirement for continued strip management throughout the growing season has reduced the adoption of this system on organic farms.