Many an Oklahoma gardener has come to grief trying to get a vegetable garden going in bermudagrass, even with an arsenal of herbicides to beat the stuff back. No wonder that few did more than roll their eyes when the Kerr Center took on the same task – using only organic methods.

Within a few years, though, the eye-rolling had turned to staring, and organic gardeners all over the region sat up and took notice. Nine years later, the Center’s Cannon Horticulture Plots are still going strong, while the bermudagrass and other weeds stay confined to the field margins.

A new report, available free from the Kerr Center website, explains how the system works. Written by retired Horticulture Manager George Kuepper, Organic Bio-Extensive Management Revisited walks through the steps that the program followed to rid the plots of bermudagrass and keep them free of weeds and full of nutrients, without using synthetic herbicides or fertilizers.

The key parts of the method are cover crops and crop rotations. The bio-extensive method keeps at least half the ground in cover crops at any one time, using them to both feed and weed the soil. Though this reduces the amount of space available for cash crops, it makes up for that by reducing the amount of time spent weeding and the amount of money spent on inputs.

Organic Bio-Extensive Management Revisited recounts the lessons learned from putting these principles into practice. An initial crop of sorghum-sudangrass literally shaded the bermudagrass out of the field. Subsequent rotations have been so effective at keeping the plots clear of it that perennial crops, like elderberries, are now successfully established in the center of the field.

The report delves into the details of tailoring cover crop mixes to particular situations. It also includes never-before-published information on biomass production from different cover crops. It addresses management strategies for periods of both drought and excessive moisture. It also includes a section detailing the conversion of annual crop beds to perennial plantings.

Organic Bio-Extensive Management Revisited is the latest in a long line of quality publications, all available free from the Kerr Center website, www.kerrcenter.com.