Rotations have been called the most important management tool in organic systems. Research at this long- term systems trial at the University of California- Davis points to starting a rotation with crops that require less nitrogen.
Rotations have been called the most important management tool in organic systems. Research at this long- term systems trial at the University of California- Davis points to starting a rotation with crops that require less nitrogen. Photo courtesy of University of California-Davis

Making the Switch

Fred Kirschenmann, a North Dakota farmer and a long- time advocate of sustainable farming systems, gives this advice in the foreword to Cereal-Legume Cropping Systems, a book for farmers who are exploring switching to sustainable production methods.

"In switching from one system to another, it is extremely important to remember that what one is doing is switching systems and not changing technologies. Many farmers have experienced severe unnecessary losses in making the switch because they failed to appreciate the difference.

"Making this switch is not simply a matter of substituting green manure for synthetic fertilizers or substituting organic fertilizers for conventional ones. Nor is it primarily substituting botanical pesticides for 'toxic' ones. Making the switch is a matter of slowly backing out of one system of farming (that relies heavily on off-farm inputs) and slowly introducing another system of farming (that relies heavily on comprehending and using nature's cycles).

"Effective use of on-site nutrient cycles as the primary source of fertility requires good organic matter, a crumbly soil structure, minimum compaction and high levels of biological activity.

"Effective pest control with reduced or no pesticide use also takes time. It takes time to break the pest cycles that have become established under monocrop management. Good pest control with fewer off-farm inputs requires a thorough understanding of the natural cycles of the weeds, insect pests, and diseases that have established themselves on your farm and then determining what crops and practices are most effective in interrupting those cycles."

Nancy Creamer, a leader of the North Carolina State University organic transition experiment comparing a range of organic systems, has benefited from the cumulative knowledge gained from the last two decades of organic farming research. Based on past research results, Creamer and her colleagues started their rotation with soybeans instead of corn and applied principles of organic weed management to achieve relatively weed-free fields. "It's possible that it's easier to farm organically now, given the cumulative experience that has been gained by farmers over the years," said Creamer.

By designing research based on results from earlier studies, Creamer and others have shown that is possible to make the transition with minimal production losses. By preparing the land, building soil, focusing on the right crops and rotation, and not putting too much acreage or too many animals into production, farmers can minimize what has come to be known as the "transition effect." Creamer's study, for example, showed that with good weed management, soybean yields can equal those of conventional beans during the first year of a transition.

How to Get Certified

USDA accredits state, private and foreign organizations to become "certifying agents." Those agents certify that a farmer's production and handling practices meet the national standards.

To initiate the process of certification, the following information must be submitted to an accredited certifying agent:

  • Type of operation.
  • History of substances applied to land for the previous three years.
  • Organic products being grown, raised or processed.
  • An organic plan, which includes practices and substances used in production.

This plan should also detail any monitoring practices that will be used to verify that the production system will be organic, including the record-keeping system, and how to prevent co-mingling of organic and non-organic products and contact of products with prohibited substances.

You will also need to evaluate and prepare a description of the physical barriers and buffers on your property that separate your operation from conventional neighbors.

After reviewing the application, if the certifying agent determines you are eligible, a qualified inspector will schedule a visit for an on-site inspection. If the application and inspection report show compliance with the requirements, certification will be granted. Once certified, you must re-apply for certification every year, and will also be assessed a certification fee of a few hundred dollars each year. Many states currently have cost share programs to offset certification fees. (Contact your local certifier for more information and see "Economic Assistance").

Rotations. Start by deciding how to build your rotation, as this is the most important management tool in an organic system. Your biggest challenges likely will be weeds and nitrogen fertility, so think carefully about how to balance those constraints with maintaining a high-value crop.Management Strategies

Grass/legume mixtures provide good cover and supply nitrogen, but if your soils are low in organic matter, you may need to incorporate the mixtures instead of cutting them for hay. Research cash crop alternatives that will help steady your bottom line. At the Rodale Institute, a five-year rotation was cut to three years to get more high-value cash crops and to allow the grass/ legume mixture to be used for improving soil fertility.

Mary Howell Martens, an organic farmer from Penn Yan, N.Y., recommends striving for balance between maintaining soil health and producing economically profitable yields. "One of the problems we've seen [is farmers] putting the whole farm into the most profitable organic crop every year. With no rotation, the yields go to pieces," she said, when interviewed for the SARE-funded educational video, "Organic Grain: Another Way."

"The crop mix that we have developed maintains our soil health and yields and also gives us a fairly profitable operation. But the overriding consideration is: What does this field need? We do put in some crops that are not particularly profitable, but then they're being rotated with the crops that make us the best income."

Begin with cash crops that require less nitrogen and can be effectively managed to control weeds. Many studies have shown that, with proper weed management, soybeans can be planted in the first year of a transition with no declines in yields. Corn, on the other hand, is not a good transition crop because it requires a lot of nitrogen and more weed management.

However, once the system is established, organic corn can be grown quite successfully, said Kathleen Delate, an Iowa State University organic researcher. Her studies show that within three years of the transition, organic corn can produce as well as conventional corn.

Avoid consecutive years of row crops to prevent weed outbreaks and maintain system productivity. University of Minnesota researchers and a dozen or so Minnesota farmers collaborating on a SARE project found that avoiding consecutive years of row cropping during the conversion to organic production could prevent weed outbreaks and maintain system productivity. The experiment, which examined the effect of crop sequence, showed that in the third year of production, the organic systems where corn or soybeans had been preceded by one to two years of small grain/forage legume versus a row crop had lower weed incidence and higher yields by the third year. This suggests that you should avoid planting two-row crops in sequence in the transition

Other considerations for the rotation:

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  • Does the rotation match the crop needs for fertility? Try to have crops with differing root depths so they can access different nutrient zones.
  • Does the rotation have sufficient diversity so that risks will be minimized?
  • Does it provide weed control?

Take advantage of mixtures and niches such as the combination of sorghum-sudangrass/lablab/cowpea planted in early summer following tomatoes and preceding corn in a California experiment.

"With a nitrophilic crop like corn following tomatoes, it's important to have a mixture that's building the soil," said Steve Temple, one of the researchers. The mixture, he continued, is designed for multiple functions:

  • The sorghum-sudangrass germinates quickly in the heat and takes up residual nitrogen. It also shades out late summer weeds.
  • The cowpea, which fixes its own nitrogen, grows productively alongside the sorghum-sudangrass.
  • When the sorghum-sudangrass dies back in early fall, the lablab, also a legume, emerges, so that by December, when all three species have winter-killed, the dense mass of cover contains fixed and recycled nitrogen.
  • With all the nitrogen accumulated and fixed in the fall, and stored in the vegetative biomass over winter, you don't have to wait for spring growth of the cover crops. The dense mixture can be plowed under and the crops planted as soon as the ground is ready.

Soils. Building soil organic matter and improving soil quality is often cited as the most critical step for a successful conversion to organic farming.

  • It may take three to five years for the soil to improve, depending on the condition of the soil, so start adding manure or composts and finding other sources of organic amendments as soon as possible.
  • Balance production, soil building and conservation. Good crop rotations that include cover crops and animal wastes help build soil organic matter.
  • Do research and start experimenting. Reading a book on compost, "made me realize I should justdo things instead of figuring out the technical parts," said John Vollmer. (See Building Soils for Better Crops in "Resources")