Using cover crops to decrease irrigation costs

Traditionally cover crops were added to a farms rotation for soil building and erosion control. With the ever increasing cost of production and demand for higher crop productivity more attention is being given to value added qualities of cover crops.

Irrigation is a costly practice many farms use out of necessity. The demand for higher yielding acres has made irrigation inevitable. The cost in some cases has put a strain on the profitability of farms. If used in rotation, cover crops can offset some of those costs.

A typical irrigation system pumps 400-1200 gallons per minute at 0.25 inches per hour, five gallons per minute per acre of irrigation. The cost of irrigation annually varies depending on many factors ranging from $15,000-$50,000, according to Lyndon Kelley, Michigan State University and Purdue University Extension educator. System efficiency and environmental factors can decrease or increase irrigation costs. Cover crops especially ones that produce large amounts of biomass can increase soil organic matter. Soil organic matter acts like a sponge by absorbing and holding water. So the question is, how much water holding capacity can we rely on by increasing soil organic matter?

The United States of Agriculture, Natural Resources Conservation Service estimates that on average bare soil can hold 1.7 inches of water. Fields that has a continuous cover, such as a pasture situation, on average has a water holding capacity of 4.2-4.5 inches. If we could raise our soil organic matter by 1%, we have the potential of raising our water holding capacity by 1 acre inch according to Jim Hooreman, Ohio State University Extension water quality and cover crop educator. That equates to 27,154 gallons of water that plants can use that is stored in soil. Hooreman also states that every pound of soil organic matter holds 18-20 pounds of water. If we were to pencil out the economics, that would be $12.00 which could add up to real savings in the fall.

For more information on cover crops and how to integrate them into your rotation contact Paul Gross or Christina Curell. For information about irrigation, contact Lyndon Kelley, Lyndon Kelley or Christina Curell. For questions in regards to irrigation costs, you can visit Lyndon Kelley’s website.