ATTRA Question of the Week

C.B.
Michigan

Answer:

Cattle have the potential to give value to cover crops in rotation, where the land might otherwise not yield an economic return. Many farmers utilize legume cover crops in rotation to build soil and increase soil nitrogen for subsequent crops. Cover crops greatly benefit small grain and vegetable yields without the use of soluble fertilizers. However, most cover crops are used as green manures and incorporated into the soil in preparation for subsequent crops. Cattle grazing on legume cover crops can benefit the farm system economically and ecologically. By selling fed steers or custom grazing yearlings, a financial return can be made on the land, and through added nutrient cycling (through dunging and urine deposition) soil fertility can be enhanced.

Grazing cattle will return 70 to 85% of the nutrients they consume to the pasture. When combined with nutrient additions from the dead leaves and roots of pasture plants, nitrogen contributions to nutrient cycling can approach 280 pounds per acre per year in a moderately managed grass/clover pasture. Pastures with a legume component of 20 to 45% are more sustainable than monoculture grass pastures, as the legumes will contribute significantly to nitrogen fertility. For more information see ATTRA’s Nutrient Cycling in Pastures.

If you are considering adding a grazing component to an existing cropping system it is wise to note that the cost of electric fencing and water delivery can eat up profits quickly, unless these structures are already in place. Consider grazing more valuable animals, such as steers or replacement heifers, instead of cows. Steers and heifers are generally maintained for a short period of time, and you will not have to cover yearly maintenance costs that are associated with keeping a cow herd. However, raising steers or heifers can require more management skill. For more information on alternative beef enterprises see ATTRA’s Beef Marketing Alternatives.

Cover Crop Selection – a few ideas

Techniques that help to build up the soil (COG, 1992):

• Ensure a balance of cash crops (corn and soybeans) and soil-conserving cover crops (clovers).

• Deep rooted crops (sweet clover, alfalfa) should alternate with shallow-rooting crops (cereals) to help keep the soil structure open and assist in drainage.

• Alternate between crops with high-root biomass (rye) and low-root biomass (oats). Pasture grasses with their high root biomass provide soil organisms, particularly earthworms, with food.

• Alternate crops that are high moisture users (corn) with plants that require lesser amounts of moisture (barley).

• Allelopathic crops (rye and sunflowers) should be alternated to prevent a build up of their natural chemical toxins.

• Alternate nitrogen fixers (legumes) with high nitrogen consumers (corn and winter wheat)

Winter cover crops that can be grazed in the late fall or early spring

Fall planted Austrian winter pea and oats (will winter kill)
Fall planted winter wheat, following corn
Fall planted hairy vetch and annual rye (will not winter kill)
Fall planted annual ryegrass in a soybean-corn rotation
Forage brassicas intercropped with corn for fall grazing (contact me if you are interested in more information on interseeding forage brassicas)

Summer annual crops for strip-grazing

Sorghum-sudan
Sudangrass
Siberian or Hungarian foxtail millet

Cool-season forages for rotations into permanent pasture

Orchardgrass
Timothy
Perennial ryegrass
Smooth brome
Alfalfa
Birdsfoot trefoil
Red clover

Economic Analysis

Before starting a new grazing enterprise, conduct an economic analysis to measure your breakeven cost, and determine how many animals it will take to make a profit. The following resources will assist you in doing a thorough economic analysis of a grazing operation.

1. University of Missouri
Downloadable livestock enterprise spreadsheets

2. Texas A&M University
Break-even Costs for Cow/Calf Producers

3. Texas A&M University
Partial Budget for Beef Cattle Management

4. Oklahoma State University
OSU Animal Science Extension Computer Software

References:

Canadian Organic Growers. 1992. COG Field Crop Handbook.

MSU. 2007. Forage Information Systems. Michigan State University Extension.