Summary Table

IAMP-Conservation Crop Rotation Practice
(NRCS Code 328)

Description

Establish a Resource Conserving Crop Rotation. Rotation must include at least one resource conserving crop as determined for Idaho in a minimum three-year crop rotation. The crop rotation is designed to either increase soil carbon and/or reduce greenhouse gas emissions. The practice may reduce soil erosion (water and wind), improve soil health, improve soil moisture efficiency, and reduce plant pest pressures. See NRCS Conservation Crop Rotation (328) and Idaho criteria for rotations as references.

Benefits

Improves soil health and organic matter; reduces weed, disease, and pest pressure; improves filtration and soil moisture efficiency; improves soil aggregation depending on specific rotation.

Soil Carbon Impacts

Depending upon the specific rotation sequence, carbon incorporation could improve from incorporated residues. The permanence of the increased soil carbon depends on the rotational sequence and specific crops.

Greenhouse Gas (GHG) Impacts

Reduced use of herbicides and fertilizers can reduce associated GHG emissions from manufacturing these products. Depending upon type and amount of carbon, CO2 production could increase as microbial driven decomposition of labile forms of carbon leads to increased respiration. If N fertilization is reduced overall in the rotation (e.g. conversion from a N-demanding crop to a legume), N2 emissions could be reduced.

Considerations for Success

  • Choose a crop rotation system that considers the following: meets goals, matches labor availability, breaks pest cycles, and minimizes soil erosion. Prioritize benefits that are the most meaningful for your operation and plan accordingly.
  • Maintain flexibility when planning a crop rotation with novel crops and be ready to adapt to unexpected challenges.
  • Consider crops that best match your soil's potential, don't require unnecessarily high input costs and are compatible with other cash crops in your rotation.
  • Tillage management should be considered in combination with crop rotation to maximize additionality of soil carbon.
  • In arid regions, if one of the crops replaces fallow, water availability could be reduced overall.
  • Herbicide carryover. Growers need to be careful based on labels.
  • The additional costs to the growers include:
    • Seed costs,
    • Fuel costs,
    • Labor,
    • Possible fertilizer costs,
    • Possible equipment costs, and
    • Marketing the novel crop could present challenges.

IAMP Preferences/Considerations

The IAMP project incentivizes practices that result in a net reduction in GHG and increase in soil carbon. To make a permanent impact on GHG reduction and increased soil carbon, one or more rotational crops should have a high C/N ratio, maximize total biomass, plant early/harvest late (e.g. winter cover crops preferable), high nitrate uptake/conversion to biomass, in 1 out of three years.

Fields are eligible for incentive only if a new crop is added to the rotation on that field. Crops may not have been planted in the last five years.

Specific Details

IAMP has several requirements for conservation crop rotation to document the practice was implemented correctly and to document the effectiveness of the practice from the current cropping strategies employed in the field. The cost of analysis of any required soil, crop, or biomass sampling and analysis will be covered by the IAMP project. For an overview of all required sampling for each IAMP practice, see IAMP required sampling. Implementing partners will be assisting with the collection of any sampling related to the practice. Each of these requirements is described below.

  1. Baseline strip: Producers will maintain a minimum strip of 80 ft in length and a minimum width of 20 ft where the baseline crop rotation will be grown as a comparison to the rest of the field. A nearby field having similar soils and climate can be used as viable alternative to the baseline strip if maintaining the baseline strip is not practical or feasible. The actual dimensions of the strip can vary to be compatible with the width of implements used to manage the field.
  2. Soil Carbon sampling: Paired soil sampling points in the baseline strip and in the treated field at the start of the project and at the end of the project is required to track the changes in soil carbon over the duration of the project, see the IAMP Soil Sampling Protocol.
  3. Soil Nutrient sampling: Paired soil sampling points in the baseline strip and in the treated field prior to planting and after harvest is required every ft down to 2 ft to assess the impacts of the practice on available soil nitrogen, and identify any nutrient deficiencies/benefits from the implemented practice, see the IAMP Soil Sampling Protocol.
  4. Crop Biomass sampling: Paired above ground crop biomass measurements at the paired soil sampling locations will be required at termination of the crop and will be evaluated for total dry biomass weight as well as the percent carbon and nitrogen, see the IAMP Crop Biomass Sampling Protocol.
  5. Evidence of reduced GHG emissions: The COMET farm or other approved crop modeling tool should indicate a minimum of 0.2 Tonne CO2eq/ac decrease in GHG emissions based on the planned crop rotation. Cover crops may be included within the rotation, which could be considered stacking depending on the rotation (see "Stacking" below).
  6. Grower supplied field management information:
    • Crop yield maps (if available for both the baseline strip and the remaining field).

Criteria/Verification

  • Crops shall be grown in a planned sequence as outlined in the IAMP contract.
  • Certificate from seed suppliers and any additional evidence (e.g. as-applied seed map) that the crops were planted and harvested as outlined in the IAMP contract.
  • Photo of each crop in rotation six weeks after planting.
  • COMET-Farm simulation of the rotational plan should indicate a minimum of 0.2 Tonne CO2eq/ac decrease in GHG.

Incentive Payments

$38/acre/year in the year(s) with an additional crop to the baseline rotation.

Stacking or Companion Practices

Conservation cropping rotations are compatible with other incentive IAMP practices implemented in the novel crop year or other years of the rotation including cover cropping, Nutrient management with reduced N applications, partial fertilization with manure, reduced or no-till, and grazing. Stacking is encouraged. Variations and creativity are encouraged with an eye to maximizing GHG reductions. If stacking with cover crop practice, must include at least one additional crop in a three-year rotation.

Sources