State of Science :: Environment
Assessing Soil Quality in Organic Agriculture
Author(s): Alan J. Franzluebbers, USDA-Agricultural Research Service, Watkinsville, Georgia
Richard L. Haney, USDA-Agricultural Research Service, Temple, Texas
The degradation of soil quality continues in the United States as a result of erosion, compaction, leaching of nutrients, and loss of soil structure and biodiversity. Organic farming methods have great potential to reverse these losses by increasing soil organic matter content and enhancing soil microbial communities.
Better tools are needed to manage the transition of soils when farming methods change from chemical-based to organic. "Critical Issue Report" number 2006.2 describes a minimum-data-set (MDS) approach to assessment of soil quality. The proposed MDS is composed of routine chemical and biological assays that can be done in most soil testing laboratories for a collective cost of less than $100 per sample.
The Organic Center plans to begin in 2007 a national pilot project testing soil quality on conventional, transitional, and organic acreage. We will apply, test and refine the MDS approach, and integrate the measures into an index of soil quality.
The Center's work on soil quality seeks to accomplish two goals.
First, we want to help develop a practical set of tools for farmers, crop consultants, extension specialists, and agronomists to deploy in the field in mapping the course for cost-effective transitions from conventional production to organic management. New tools are needed to determine how quickly a soil can be transitioned, how resilient the soil is likely to be during the transition process, and how soils and crop yields are likely to respond to key organic farming practices and inputs.
Our second goal is to develop methods to quantify the benefits to farmers, rural communities, and the nation from the improvements in soil quality possible through organic management. Key benefits that will follow expansion of organic production, and which need to be quantified, include:
- Increased efficiency of nitrogen use;
- Less reliance on purchased sources of nutrients;
- Reduced runoff and leaching of nutrients and pesticides, and hence improved water quality;
- More stable crop yields; and
- Higher returns to farm labor and management.
The Center's next "Critical Issue Report" focusing on soil quality will be released in the spring of 2007. It will address the potential of organic farming systems to increase the efficiency of nitrogen use in corn production in the Midwest.
The Center wishes to thank the authors of this report, Alan J. Franzluebbers, USDA-Agricultural Research Service, Watkinsville, Georgia, and Richard L. Haney, USDA-Agricultural Research Service, Temple, Texas for providing a sound foundation for our evolving work on soil quality.