The USDA-ARS farming systems project: evaluating the sustainability of organic and conventional cropping systems in the mid-Atlantic

Cavigelli, M.A., Teasdale, J.R., Szlavecz, K., Nichols, K.A., Green, V.S.

Technical Abstract
Organic farming has been proposed as a means of increasing environmental and economic sustainability of cropping systems, but very little data exist on which to base such an assessment.

A long-term cropping systems trial was established at the Beltsville Agricultural Research Center, Maryland in 1996 to evaluate the sustainability of three organic systems, one no-till system, and one conventional till system.

The three organic systems differ in length of crop rotation. Sustainability of the systems is being evaluated based on agronomic performance, soil quality, nutrient dynamics, soil biological activity and community structure, and economic performance.

Results to date show that corn yields tend to be highest in the conventionally tilled system while yields are similar in the no-till system and in the organic system with the longest crop rotation.

Among the organic systems, corn yields tend to increase and weed populations tend to decrease with increasing crop rotation length. This corn yield rotation effect seems to be driven more by short-term nitrogen availability and weed population effects than by long-term changes in soil properties.

Soil quality, however, does seem to be higher in one of the organic systems than in the no-till and conventional systems. In addition, this same organic system seems to be retaining more N than the other systems.

Soil invertebrate communities are different in no-till, conventional and organic systems; the effect of these differences on soil water infiltration is being investigated.

Economic analyses are being conducted to provide a more complete picture of overall system sustainability.

 

Source
2004. [abstract]. Mid-Atlantic Ecology Conference. Paper No. 4.

 

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Posted August 2007