Buckwheat Fights High Fertilizer/Chemical Costs

Buckwheat Fights High Fertilizer/Chemical CostsOn Feb. 25, Silvia Abel-Caines delivered a lecture at the Midwest Organic Sustainable Education Service (MOSES) annual conference. The venue for the conference was LaCrosse, WI, and her presentation was titled “Emergency Forages for Ruminants: Buckwheat Silage In-House.” Her lecture addressed the following concerns: With ever-increasing likelihood that extreme weather conditions may become (and remain) the new norm, there is a need to explore options to extend or replace forages in dairy and beef rations. She stressed that such need strongly encourages the culture of buckwheat (Fagopyrum esculentum). This crop enjoys several positive attributes, thus offering increased appeal to growers faced with runaway crop input costs, as well as climate uncertainties.

F. esculentum is a moisture-loving, cool climate, summer annual grain, and has been grown as a grain crop in China for over 10 centuries. Buckwheat is one of the quickest-growing green manure crops, taking only four to six weeks from planting to flowering, plus another four to five weeks to seed maturity. It’s used to suppress weeds, protect soil from erosion, attract beneficial insects (including honeybees) and build organic matter. This crop repels weeds through a trait called allelopathy. This means that it secretes a chemical which serves as a natural herbicide, which seriously discourages many other plant species. Buckwheat may still be used as a smother crop, due to its allelopathic properties. It is a good competitor because it germinates rapidly, and because its dense canopy shades the soil. Thus, this rapid growth chokes out most weeds.

Agronomy researchers at University of Wisconsin-Madison have shown that buckwheat’s dense canopy does, in fact, soon shade the soil, rapidly choking out most weeds while stealing solar radiation from less aggressive plant species. Thus, it’s often praised as a useful crop for controlling quack grass in Northeastern states, particularly if the land has been thoroughly tilled to break up this pesky perennial’s sod. Ideally, such fields should be fall-plowed or early spring-plowed and disked or field-cultivated just before planting time. Weed scientists report that buckwheat can be used to eradicate Canada thistle, sow thistle, creeping jenny, leafy spurge, Russian knapweed and perennial peppergrass.

F. esculentum can also increase phosphorus’s and micronutrients’ availability for the cash crop following in the rotation. It does so by liberating complexed soil nutrients through a process called acidulation. With this phenomenon, this plant’s root tips secrete acids (typically malic and citric) which chemically separate phosphorus and trace elements from soil particles. These, in turn, nourish the buckwheat, usually with enough of these liberated elements left over to feed the next crop in the rotation. However, this crop doesn’t fix nitrogen. Mature seed averages about the same amount of protein (12% – 13%) as most other small grains.

Buckwheat as a broadleaf annual crop normally reaches heights of two to three feet, with a single succulent stem, several branches and flowers varying in color from white or light green to pink or red. It forms a dense fibrous root system with a deep taproot. Most of its roots are concentrated in the top 10 inches of soil. Its biomass (total dry matter per acre) ranges between 2,000 and 3,000 pounds. In addition to being very attractive to honeybees, this plant also invites wasps and parasitic flies. But it does have two major shortcomings: its intolerance to frost and its extreme susceptibility to herbicide residue injury. This herbicide intolerance is most of the reason why buckwheat acreage has dropped significantly since World War II. At that milestone, many of the chemicals used to make wartime munitions were diverted to ag chemical (pesticide) production. Early in the 20th century approximately one million acres in the U.S. were planted to buckwheat. But by the 1960s that figure had plunged to 60,000 acres – a level at which it currently remains, more or less.

Buckwheat can sensibly be planted until July 15, particularly on land which has been unproductive, often taken over by goldenrod and burdocks. Prepare a good seedbed, but don’t pulverize it. Plant like other small grains, drilled or spun on, but only plant 50 pounds/acre – unlike most small grains, seeded at much higher rates. Drag in lightly, if spun on. Buckwheat tolerates pH of 5.0 to 6.0 as well as generally low fertility. Thus, this crop provides a great way to bring back abandoned land.

From a human health standpoint, University of Illinois (UI) scientists have found that dark-colored honey – specifically dark-colored honey produced with nectar from buckwheat blossoms – contains 20 times the amounts of antioxidants found in paler honey varieties. Quoting these UI researchers: “Antioxidants are the body’s first defense against free radicals that produce inflammation and tissue damage. Although increasing antioxidants won’t reverse damage already done by free radicals, it can prevent further cell deterioration. Buckwheat honey packs the antioxidant power of the vitamin C in a tomato.”

I’ve had good luck recommending folks plant 40 pounds of Japanese millet and 20 pounds of buckwheat per acre. The buckwheat liberates nutrients for the millet through its acidulation properties. It’s allelopathic properties discourage weed competition. Yet interestingly, allelopathy does not seem to throw a curve to the millet seedlings. Another recommendation that has worked out well has been a blend of oats, tillage radishes and buckwheat. I’ve recommended, per acre, five pounds of radish seed, 25 pounds of buckwheat and a bushel of oat seed. The buckwheat will die with the first killing frost, but by that time it will have achieved its acidulation and allelopathy missions. Then the radishes will do their soil penetration thing, accompanied by the oats. When it gets really cold on the other end of the growing season, the radishes and the oats call it quits. But all three crops will have done a great job of maintaining ground cover, quietly self-composting under the snow.

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