Editors note: As we see more and more interest in organic production, the issue of transitioning from conventional farming becomes a critical issue. The following article by Dr. Sanchez is reprinted from the Vegetable and Small Fruit Gazette, Penn State Dept. of Horticulture, which can be found online at: http://hortweb.cas.psu.edu/extension/vegcrops/newsletterlist.html.
The transition phase can be difficult for growers transitioning to organic production. During the transition phase the farming system is undergoing many changes in physical, chemical and biological properties. The transition phase is typically accompanied by reduced yields until the farming system reaches a new equilibrium. Further, crops produced during the transition phase cannot be marketed as organic or transition organic. As a result growers must be prepared to operate with the reduced incomes typically accompanied with reduced yields during the transition phase. Below are some tips for the transition phase adapted from Zinati (2002). Keep in mind that factors such as location, soil type, pest pressure and environmental factors can affect the efficacy and implementation of these tips.
1. Select land with a high nutrient status, good soil structure and low pest pressure to transition first. A grower can transition separate fields at different times to organic production. A strategy for transitioning fields, particularly with high pest pressures may be to use a pre-transition phase (See tip 8).
2. Include legumes in the crop rotation to supply nitrogen to the soil and reduce pest pressure. Different legumes add different amounts of nitrogen to the soil. The Commercial Production Recommendations Guide for Pennsylvania includes a table with nitrogen values for different legumes used as green manures. Even when the legume is grown as a cash crop, incorporating the plant reside after harvest can add some nitrogen to the soil.
3. Start the transition by planting a crop with low nitrogen needs. This strategy will provide more time for adding nitrogen to the soil using other fertility management tools including green manures, manures and compost.
4. Use green manures, manures and compost to increase soil organic matter, water infiltration and reduce soil erosion. Green manures, manures and compost are already important tools for fertility management in organic systems.
5. Alternate cool season crops with warm season crops to break weed cycles. In surveys of organic growers, weeds typically are listed as the biggest pest problem in organic production. This is one strategy for their management.
6. Use timely disking and over-seeding as other strategies to manage weeds.
7. Experiment on a small-scale before adopting a pest management strategy on a large scale. This can reduce risks in the event the pest management strategy fails.
8. While a 3-year transition phase is required for certification, a pre-transition phase may help alleviate decreased yields during the transition phase. A pre-transition phase may be useful for fields with high pest pressure. During a pre-transition phase conventional pest management tactics are used along with organic tactics to reduce pest pressures. Once pest pressures are reduced organic pest management tactics are used exclusively.
Originally printed in Virginia Vegetable, Small Fruit and Specialty Crops – January-February 2004.
Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.
July 29, 2009