With the renewed optimism in corn, soybeans, wheat and other cash crops, there is more pressure to produce more on each acre of land. There has been some loss of hay and pasture land to these crops. Forage inventories are tight and hay prices are at record levels. Double cropping, by seeding a cover crop after a cereal crop, is an opportunity to produce additional forage for your livestock. Oats seeded after winter wheat harvest with manure applied can yield 1 - 3.5 tonne of dry matter (DM) per acre. Even in fields without manure, oats can yield 0.5 - 1.5 tonnes of forage DM per acre. At hay prices of well over $100 per tonne, forage cover crops can give a good return in addition to the cereal crop harvested.
Summer Seeded Forage Cover Crop Study
Many cover crop plant species are used as forage, such as oats, barley, peas, triticale, rye, turnip, and various mixtures. A 2005 cover crop study compared red clover underseeded in the winter wheat to oats, oilseed radish, peas, annual ryegrass and sudan grass seeded after a cereal crop were harvested. (Figure 1) Applying manure before seeding significantly increased forage yield, with the exception of red clover. Oats produced the most forage yield, with the exception of red clover with no manure or annual ryegrass with manure applied. Volunteer winter cereals yielded only 50 - 75% of a seeded oat forage yield.
Figure 1. 2005 Cover Crop Yield
In another study where cover crops followed spring wheat, the volunteer spring wheat yielded about the same as many of the cover crops. In this study, cover crop yields were 0.5 - 1 tonne per acre. In both these studies, the highest forage yields were from annual ryegrass with an application of manure.
It may seem early to be talking about August seeding, but now is the time to start planning. Establishing a cover crop can be done using a no-till drill. Alternately, broadcasting the seed followed by a light tillage pass, such as a cultivator or rotary harrow, to incorporate the seed. Some tillage before seeding can reduce disease and weed pressure from the preceding cereal crop. Under dry conditions, following with a packer will firm the soil for better to seed-to-soil contact and help retain moisture for better emergence. Manure can be applied immediately before planting and incorporation will capture more of the readily available nitrogen in the manure.
Cover crops can be easy grazed or harvested as silage or baleage. Strip grazing with cattle or sheep is very efficient. (Figure 2) These crops are essentially impossible to make into dry hay at that time of year. Cereal crops summer seeded as a second crop with adequate moisture are usually ready to begin grazing about 45 - 60 days after planting (Figure 3). They should be grazed before the heading-stage of the cereals, as forage quality will then begin to decline.
Figure 2. Strip Grazing of Kale, Pea, Barley & Oat Mixture
Figure 3. Barley seeded following winter wheat for fall grazing
A question that often is asked is "does late-fall and winter grazing compact the soil?" Research from Nebraska with beef cattle showed winter grazing crop residues had no significant effect on the following year grain crop yield, and additional tillage was not required. However, spring grazing increased the soil's bulk density and decreased water infiltration rate. Therefore, cattle should not graze crop residues after the soil has thawed in the spring.
Using cover crops following a cereal crop provides soil protection from wind and heavy rains in the fall months before freeze up. It also helps build soil organic matter and grazing livestock can improve nutrient recycling. Red clover can fix nitrogen for the following crop. Cover crops also provide the livestock farmer a place to spread manure in late-summer and reduces the nitrogen that could be lost to the environment. The most immediate benefit to the livestock farmer will be the extra feed produced, getting more from the land, rather than using more land!
For more information about Cover Crops, see Cover Crops: Adaptation and Use of Cover Crops,
Cover Crops: Cover Crop Types - http://omafra.gov.on.ca/english/crops/facts/cover_crops01/cover_types.htm
Cover Crops: Choosing a Cover Crop -