FAQs about Crops and Conservation
Why should I worry about erosion when my yields are continually increasing?
Soil erosion has costs that farmers don’t often recognize. Soil organic matter is needed to produce a crop, and losing this to erosion is a cost that isn’t often considered. We can keep adding inputs to offset the loss of soil organic matter, but this is a cost. For example, if your soil has 5 percent organic matter, the loss of a ton of soil would include 100 pounds of organic matter. It is difficult to determine exactly the value of this organic matter but if we use the cost of dry weight manure as a proxy, then organic matter would be worth about $.10 a pound. So, 100 pounds of organic matter would be worth approximately $10 per ton of 5 percent soil.
Will I see a yield decrease from no-till?
Any new practice comes with a learning curve, therefore results in the first years of no-till may vary. Experienced ILF cooperators report average yield reductions of 5-6 percent in corn and actually experience higher average soybean yields with no-till practices.
More importantly, even with a lower yield, no-till can be more profitable because less labor, fuel, and machine hours went into producing the crop. Generally, less equipment and horsepower is needed for no-till systems, so the fixed costs of your system can be reduced as well.
What are some benefits of using cover crops in my corn-soybean rotation?
Cover crops can provide significant benefits to soil and water quality improvement, especially during off-season row crop production (e.g. corn and soybean), where the soil is vulnerable to water erosion and the potential of nutrient leaching to groundwater is increased. Living cover crops increase the potential of an active root system to intercept soluble chemicals such as nitrate, and provides a source of organic matter input through above- and below-ground biomass.
Some of the challenges that producers face are the selection of cover crop varieties and the short window of growing, particularly in the Midwest. Winter hardy varieties of cover crops are typically planted after the row crops are harvested in the fall and provide cover for the soil until they are killed in the spring prior to planting of the next crop.
For further information about cover crops:
Cover Crop Selection and Management for Midwest Farming Systems ILF Winter 2006 newsletter
Small Grain Cover Crops for Corn and Soybeans PM1999
Legume Living Mulches in Corn and Soybeans
What are some considerations when making the decision to convert CRP acres into crop production?
The Conservation Reserve Program (CRP) was established to protect highly erodible land by taking it out of row crop production to reduce soil erosion. Producers enter into 10 to 15 year contracts or longer depending on funding availability for the CRP. Many of the original CRP contracts have or will expire in the next few years, leaving producers with the decision of what to do next.
If the choice is made to convert these acres into crop production, it is important to remember that the soils are highly erodible. Careful planning is needed in order to sustain the soil and environmental benefits that have been established over the years that the land was under CRP. Careful selection of tillage systems that are suitable for CRP such as no-till, or permanent conservation practices (terraces, grassed waterways, buffer strips, etc.) will be essential in reducing soil erosion.
The use of annual or perennial cover crops in the crop rotation is another practice that should be considered in the conversion of CRP to row crop production. Cover crops sustain the gained benefits of soil organic matter build up, microbial biodiversity, soil structure, and other physical and biological improvements that are essential to soil and water quality.
For further information about CRP and crop production:
Tillage options after CRP - CRP Issues and Options
Planting corn or soybeans into CRP sod ground - CRP Issues and Options
Applying Fertilizer and Lime to CRP Land; ISU Extension
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