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Converting CRP to Cropland: Management Considerations
Management Considerations
Converting Conservation Reserve Program (CRP) acres back to cropland requires
proper planning. Several things need to be considered in the planning process to
ensure a successful transition. These include:
- Maintain concentrated flow areas or other critical eroding areas in
grass cover
- Consider continuous CRP practices such as grassed waterways, field
borders, cross wind trap strips, filter strips, or other appropriate buffer
practices
- How to effectively kill existing cover including the amount of residue
and cover type (cool-season grass, warm-season grass, grass/legume mix) to
plant and establish initial crop
- Soil moisture and other soil limitations such as available water
capacity that will limit crop growth
- Planned crop rotation
- Tillage and planting system
- Soil fertility (nutrient management planning)
- Pest management
- Impacts on environmental quality
- Conservation Compliance requirements on Highly Erodible Land (HEL)
Cropping Considerations
Primary
considerations for converting CRP to cropland are how to effectively kill
existing cover, conserve soil moisture, and maintain soil quality. The
recommended method for killing existing cover is to use a systemic herbicide,
such as glyphosate along with other appropriate herbicides such as Dicamba or
2-4-D. It is important to manage the CRP stand to maximize herbicide uptake, and
to time application to coincide with carbohydrate transfer to the root system to
get a good kill. Managing CRP using measures such as haying, grazing, or
shredding to stimulate new shoot growth and to minimize dormant root buds prior
to applying the herbicide will improve the effectiveness of the herbicide
application. Selecting herbicide resistant crops will allow for subsequent
herbicide treatments to control escapes. Soil moisture conditions impact the
effectiveness of the herbicide application because drought stressed plants will
not absorb or translocate the herbicide. Soil moisture conditions also need to
be considered in choosing whether to plant a fall or spring crop. Several
factors need to be considered to decide what crop to plant on converted CRP.
These include profitability, protecting or enhancing soil quality, controlling
soil erosion, managing pests, and effectively using available soil water.
Diverse cropping systems including small grains, warm-season row crops,
broadleaf crops such as sunflowers or legumes, and maximizing high residue crops
used in rotation are most effective. Consult with local Natural Resources
Conservation Service staff to select a crop rotation that controls soil erosion,
maintains soil quality, and works best with the tillage system utilized.
Tillage System Selection
No-till
is the preferred method when converting grassland to cropland to maintain
benefits accrued over the last 10-to-15 years in CRP. Research has shown that
there have been significant soil quality improvements in soils that have been in
CRP for an extended period. No-till systems in conjunction with a diverse crop
rotation, and minimal fallow periods are most effective to improve or maintain
soil organic matter, aggregate stability, soil infiltration, and available
water-holding capacity. These improvements result in soil that is in better
condition to grow plants over the long-term. If tillage is necessary to level
the field, limit it to the first year and only involve implements (harrows,
blade/roller, aerator, etc.) that lightly disturb the soil surface, or sweeps
that undercut vegetation leaving protective residue cover on the surface.
Conventional tillage systems can destroy most of the soil quality improvements
gained under CRP over the last 10-to-15 years in just the first year.
Fertility
Soils that have been in long-term CRP cover can be different than soils that
have been cropped regularly over the last decade. Soil tests to determine
fertility should be completed before fields are returned to production allowing
ample time to schedule and apply fertilizer required for planned crops. In areas
where soil test phosphorus levels are low, consider applying starter fertilizer
at planting. If residue levels are heavy, nitrogen may be temporarily tied up by
soil micro-organisms and nitrogen rates may need to be increased by 10 percent
over recommended rates to compensate. Consider use of a legume cover crop or
forage crops to improve the transition to the first cash crop. Legumes fix
atmospheric nitrogen and have a low C:N ratio which allows them to readily
decompose remaining sod residue, provide nitrogen, and allow for an easier
transition to the following crop.
Soil Erosion and Highly Erodible Land
Depending on the cropping system, soil erosion rates can increase
significantly when HEL is cropped compared to land maintained in sod. The
Conservation Compliance provisions of the Food Security Act require U.S.
Department of Agriculture program participants who produce annual agricultural
commodities on HEL fields to apply an approved conservation system on those
fields. In addition to controlling erosion by wind and water, the conservation
system applied must also control gully erosion and prevent off-site damages to
be considered acceptable. Check with your local NRCS office for specific erosion
estimates, and alternatives for different cropping/tillage systems.
Impacts on Environmental Quality
Land enrolled in the CRP has provided many natural resource benefits. Soil
erosion, soil quality, water quality, air quality, and wildlife have all been
positively impacted by the establishment of grasses, legumes, trees, and shrubs.
It is important to consider impacts to these resources as you decide whether and
how to transition CRP acres back to crop production. Potential effects of
converting CRP acres back into cropland include excessive soil erosion, reduced
soil quality, loss of wildlife habitat, and degradation of water quality.
Contact your local NRCS office for assistance with planning the transition
from CRP back into cropland.
This information is also available for download and
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Fact Sheet -
Converting CRP to Cropland: Management Considerations (PDF; 129
KB) Last Modified:
07/19/2012
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