The goals of sustainable agriculture include decreased reliance on synthetic nutrients and pesticides and improved environmental quality for the long-term benefit of the land, livelihood of growers, and their communities. Cropping systems that maximize these goals use alternative fertility and pest control options to produce crops with minimal soil erosion and nutrient leaching. Cropping system elements that can help achieve these goals include: reduced tillage, cover crops, and organic soil amendments. Cover crops are grown before the cash crop and used to replenish the soil with nitrogen and organic matter. Cover crops often also influence pest populations and can be selected based on site-specific growing conditions. Cover crops can be mulched on the soil surface to prevent erosion and weed emergence or can be tilled directly into the soil to incorporate nitrogen and organic matter. Green waste mulch is an increasingly used soil amendment. Many municipalities are encouraging farmers to use green waste mulch in farming systems as an alternative to green waste disposal in landfills. Reduced tillage was once restricted to large-seeded field crops but recent technical advances have made it a feasible option for vegetables and other horticultural crops. Alternative farming practices; however, are still only used by a small minority of growers. Increases in price for organic produce and changes in laws governing farming operations may increase adoption of alternatives to conventional agriculture.
In the southeastern United States as in many parts of the world, a large percentage of modern commercial vegetable production relies on the use of raised-bed, plasticulture production systems, especially for warm-season crops ( Lamont, 1996
fields are traditionally fallowed during the hot summer months, creating a gap in the production season of 2 to 3 months to integrate cover crops into the vegetable production system.
Summer cover crops that fit into current desert production practices
the fruit inside the crop canopy also suffers due to poor fruit color. The umbrella system tends to have a large fluctuation in fruit production with poor fruit quality ( Papadopoulos, 1994 ). Cucumbers harvested from the upper canopy generally have
supplemental N is as follows ( Olivier et al., 2006 ): Fig. 1. Steps in the Walloon Agricultural Research Center (Gembloux, Belgium) decision support system for managing the nitrogen fertilization of a potato crop at field scale. where HNT 70 is the CM reading
compost and cover crops are integral components in organic management systems. Compost is applied to promote soil biological activity ( Raviv, 2005 ), suppress disease ( Stone et al., 2003 ), increase soil organic C ( Jackson et al., 2004 ) and supply
herbicides are disallowed in organic production, termination of cover crops through organic-compliant methods constitutes a major challenge. Although the majority of cover crop studies have been reported from conventional systems using herbicide inputs, cover
We thank the Organic Farming Research Foundation for funding this evaluation of summer cover crop species. We also thank Jane Frampton, Joe Difeo, and Tim Mathews for their technical support, and the staff at the Tidewater Research Station
authors have debated the applicability of this general concept to agricultural WUE since crop production involves multiple and interacting factors that cannot be described by a simple input/output system. In addition, the amount of water that is not used
done with water lines and nozzles placed in or above the crop canopy. This method has proven effective for low-growing crops such as tomato as well as for vine crops and tree fruit ( Bootsma and Brown, 1985 ). A permanent system of microsprinklers with