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A Valuable Investment in Soil Health

Cover crops can boost soil health. But there is much to learn about which species work best in Oklahoma and Texas.

By Lisa Bellows, Ph.D., North Central Texas College Department Chair of Science

Posted Dec. 20, 2017

Many landowners spend considerable time and money investing in generational transfer of property. These same folks contribute to college funds for children and retirement accounts for themselves. They are well aware of long-term investments and appreciation of assets. Through annual evaluation of portfolios and scheduled contribution to their various accounts, they plan for the future. With land being one of the longest-term assets in a financial portfolio, an investment in soil health should be considered a priority for their future and the future of their heirs.

Cover crops can be a valuable investment in the soil health portfolio, but, like selecting the best mutual funds or timing of investments for your financial portfolio, selection of seed varieties for the cover crop mix and determining the best time to plant are two factors that require careful consideration.

Half-hearted consideration of seed selection became evident a few years ago when a farmer friend had no clue what seed varieties were in his planter box nor what the seedlings would look like if his seed germinated. This situation sparked a question for Noble Research Institute's soils and crops consultant Jim Johnson, and a research project was initiated with 93 varieties of cover crop seed species planted as monocultures to determine which varieties would best perform as winter cover crops in the North Texas and southern Oklahoma region – a region dominated by warm-season pastures for grazing and hay production. The idea was that if the seed variety performed well as a monoculture in our pastures, it would likely benefit soil health in a cover crop mix. If the variety failed to thrive or performed at a lower rate than others in the legume, grain or brassica classes, it would likely not be a good choice for a cover crop mix in the region.

As anticipated, some varieties performed favorably, and we still don't know what a few of the 93 varieties look like as seedlings because they did not perform at all in our region. Faba beans endured our winters, wooly pod vetch matured earlier than other vetch varieties, and brassicas did not stand much of a chance getting started in well-established grass pastures. Planting time of cover crops in pastures also emerged as an unexpected factor in the research. Well established, grass-growing pastures suppressed seed germination. Summer cover crops failed to compete with established perennial grasses, and planting before frost in the fall was also a deterrent for the cool-season cover crops.

Cover crops can be a strong allocation in your overall soil health portfolio. Just as with planning financial portfolios, soil health is a long-term endeavor. There are no magic bullets, and understanding the seeds you are investing your money and time into can yield dividends.

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