Conservation Tillage Systems in the Southeast

Economics of Cover Crops

Overview

Using cover crops increases production costs in both time and money. The cost of seed and planting along with the time associated with cover crop management can be a deterrent to using them. For example, growers need to adjust their schedule of operations to address both timely cover crop planting and termination. This adds to field operations when compared to conventional systems. However, costs associated with cover crop management may be offset by eliminating costs for certain inputs, such as nitrogen fertilizer or energy-intensive tillage operations. As a result, overall production costs could decrease by using cover crops, but costs versus benefits will vary across operations.

Depending on the system and the intended cover crop benefit, a return on investment may or may not be noticeable in the short term. For example, better water-use efficiency can reduce irrigation costs because residue on the soil surface improves water infiltration and reduces evaporation, and increased soil organic matter improves water-holding capacity, all of which increases plant available water. The increase in plant available water can sustain the crop during periods of short-term drought and can increase yield. This may eliminate a scheduled irrigation and thus save money. Many benefits associated with cover crop use, such as improved soil quality, are difficult to quantify in the short term, but ultimately improve the bottom line over the long term.

Factors affecting the economics of cover crops:

  • cash crop grown
  • cover crop selected
  • time and method of establishment
  • time and method of termination
  • cash value applied to environmental protection, soil productivity and soil protection
  • cost of nitrogen fertilizer and the nitrogen supplied by the cover crop
  • fuel cost
  • any increase or decrease in cash crop yield due to the cover crop

Input Costs

Cover crop seed costs vary considerably from year to year and from region to region. Legumes can cost up to twice as much to establish as small grains. The increased cost of legume seed can be offset by the value of nitrogen that legumes provide. Properly managed legume cover crops can be expected to supply at least 50 pounds of nitrogen per acre. On the other hand, a grass cover crop, such as cereal rye, terminated at a late stage of growth, may increase the cash crop’s nitrogen fertilizer requirements by 25–30 pounds per acre. However, high-residue cereal cover crops can suppress weeds in the short term and can increase soil organic matter, and hence soil health, in the long term.

The Importance of Good Management

The benefits of cover crops are well known, but there are additional costs and time commitments required to ensure timely field operations that result in adequate biomass levels. The full benefits are realized only when you commit the time and attention that is required to manage a cover crop properly. If poor management results in no residue or minimal cover crop growth, the expense of planting a cover crop in the first place would be wasted. Poor management decisions can result in yield losses or cash crop failure. Therefore, when you assess the cost of using cover crops, you must account for the time you spend to manage them.

Download the tables from Chapter 5.

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