The Worlds Finest Cover Crop

The most popular cover crops get on the top seller list for two primary reasons. Cereal rye, buckwheat, annual rye grass, vetch and oats are popular because of their ease of establishment and their ability to produce seed which can be harvested and sown again.

Unfortunately even this elite group of cover crops can be difficult and costly to grow as a short term green manure or as a companion with a primary crop. The relentless march of a short growing season can make even a well timed planting a costly failure if suitable rain for germination is two or three weeks late.

Here at humus we feel certain that cover crops could play a major role in resolving some of our national soil erosion and agricultural stability problems. Their ability to recycle nutrients, aerate the soil and control erosion make cover crops much more valuable than mere crop residue.

The time has come to get serious in the search for the worlds finest cover crops. Our feeling is the brightest candidates are in that large family of plants that grow reliably year after year when the season is right, cost nothing and commonly get the moniker of "weed."

Yes, the idea is a little far out, but consider this- we are well along in developing herbicide technologies that are very selective of the plants controlled, and some of these herbicides can be applied through a wide range of crop growth stages. Roundup tolerant crops are an obvious example.

It is clearly conceivable that various combinations of herbicide and cultural practices could be developed that would encourage weed growth in a seasonal pattern as a short term cover crop or companion crop. One of the key areas of research that is missing is the impact of various short term weed flushes at various crop growth stages. Both physical and chemical evaluations are needed as we learn more about alleopathy and homeopathy.

We anticipate that we will soon quantify situations where specific species of short term weed companion crops actually have a beneficial impact on grain yields, while providing the erosion control, nutrient cycling and biological diversity of a cover crop. After these weeds are selected it may become practical to actually allow a "desirable weed" to proliferate one year to produce a self sown seed crop with the legendary ability of a weed to persist in the soil and remain viable for season after season if it is not held back by a cultural or herbicide practice.

So ode to the pigweed, the lambsquarter and velvet leaf, on foxtail, panicum, purslane and dandelion. You're all nasty weeds, but could we still be friends?

email to: livingland@humus.com

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