Volunteer Pea or Small Grain for Animal Feed in the Fall (8/2/12)
There may be some opportunities to grow some animal feed after early season crops like peas and wheat are harvested. The opportunities of course depend on the availability of rainfall and residual soil moisture.
DRY PEA. Dry peas are being harvested and some fields are tilled just after pea harvest or may receive a late chemical burn-down to prepare the field for the next season. There are opportunities to utilize these fields for volunteer pea feed or a cover crop. At harvest a small percentage of the dry field pea seeds will have dropped to the ground, even when combines are well adjusted. These seeds may be stimulated to germinate and start growing. This may require a light harrowing of the field to incorporate the seed. Soil moisture is essential for germination to take place. As the stimulated volunteer plants follow a main crop of field peas, there will be high numbers of Rhizobium leguminosarum bacteria inoculum in the soil and nodulation is typically excellent. The growing pea plants will provide a soil cover and protect the soil from erosive forces. This system can make use of the remaining growing season since field peas are tolerant to minor frost. The total amount of biomass produced depends upon the pea plant density, the timing of initiation of re-growth, soil moisture, rainfall, and the date of a killing frost. However, there is not enough time left to expect to harvest a second dry pea crop for seed. The volunteer pea crop can be used for grazing. Research at Carrington in 2008, found that fall produced dry pea biomass reached 1,500 to 3,000 lb/a. After grazing, pea stubble can be worked into the soil as a green manure or left over the winter.
SMALL GRAINS. Similarly to dry pea, residual small grain seed such as wheat, barley or oats can be worked into the soil with a light harrowing to assure good seed to soil contact. Sufficient moisture in the top soil is needed for germination. The volunteer grain will take up some of the residual nitrogen, but as it is following a main crop just harvested, there may not be sufficient N available for the plants to maximize productivity.
If sufficient rain is available some additional nitrogen applied after emergence and establishment, to stimulate crop growth, may be beneficial. The risk of this system comes when winter wheat is planted in the neighborhood of the volunteer small grain crop. The green volunteer crop forms a “green bridge” for the Wheat Curl Mites that vector the wheat streak mosaic virus, a disease which can survive on grassy weeds, corn, and the volunteer grain. The mites might move from the growing volunteer crop to the newly seeded winter wheat, putting the winter crop at risk. Under good growing conditions a volunteer wheat crop can produce about 3,100-3,500 lb dry matter/a (see Table and photograph).
Dry pea or small grain volunteer systems both will use soil moisture and this may deplete the reserve for next year’s subsequent crop. Other options to increase the chances of getting a well-established stand of a feed crop is to broadcast some additional small grain seed or other species that develop well in the fall, such as radish. The systems described will work best with grazing as there is generally not enough tonnage to justify haying.
Extension Agronomist Broadleaf Crops
Extension Agronomist Grain Crops