Summary Table

IAMP-Reduced tillage from conventional
(NRCS Code 345)

Description

Limiting soil-disturbance from tillage by modifying methods to those that limit inversion tillage operations such as moldboard plowing and harrowing with chisel or similar implement. Alternative conservation tillage methods acceptable under this practice include strip-till, ridge-till, mulch-till, and vertical/shallow-till methods. Fewer passes, strip-till, etc. minimizes soil disturbance by implementing less intensity, shallower depth and area disturbed. This practice also includes the management of crop residue to protect soil surfaces (or taken directly from NRCS 345).

Benefits

Reduce erosion, increase water holding capacity, improve soil health, increase organic matter, reduce off-site losses and availability of easily transported nutrients, reduces pressure from some pests, reduces expenses associated with tillage operations.

Soil Carbon Impacts

Improve soil carbon retention by reducing exposure of SOM to O2 and allowing SOM to stabilize.

Greenhouse Gas (GHG) Impacts

Reduce CO2 emissions from soil by reducing exposure of SOM to O2 and potential for reduced emissions associated with equipment.

Considerations for Success

May require equipment not currently owned. Rental equipment may be available through your soil and water conservation district or other local sources.

IAMP Preferences/Considerations

The IAMP project incentivizes practices that result in a net reduction in GHG and increase in soil carbon. To make a lasting impact on GHG reduction and increased soil carbon, tillage reduction should be adopted permanently throughout the cropping rotation. Plowing after reduced till can expose labile SOM to O2.

Specific Details

IAMP has several requirements to document that the reduced-tillage 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 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 can either maintain a minimum strip of 80 ft in length and a minimum width of 20 ft where the historic baseline tillage practices are still applied or identify a nearby field that will continue to receive the same historic baseline tillage practices as a comparison to the rest of the field. 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 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. Erosion limits: Planned tillage activities must me the following NRCS criteria.
    1. The soil tillage intensity rating (STIR) value equivalent calculated using ARS spreadsheet tool or RUSLE2 based on planned is no greater than 80.
    2. Soil erosion rates predicted by RUSLE are less than soil tolerance levels (T).
    3. Soil erosion rates are less than soil tolerance levels (T).
  5. Grower supplied field management information:
    1. Crop yield maps (if available for both the baseline strip and the remaining field).

Criteria/Verification

  • Uniformly distributed residues over the entire field (Removing residue from the row area prior to or as part of the planting operation is acceptable).
  • Direct measurement of ground cover (through analysis of images or direct measurement) following tillage.
  • The soil tillage intensity rating (STIR) value equivalent calculated using ARS spreadsheet tool or RUSLE2 no greater than 80. Documentation for verification will be provided by implementing partner. The STIR value shall include all field operations that are performed during the crop interval between harvest and termination of the previous cash crop and harvest or termination of the current cash crop (includes fallow periods).
  • Soil erosion rates are less than soil tolerance levels (T).

Incentive Payments

$40/acre/year of implementation.

Stacking or Companion Practices

Reduced tillage is compatible with other incentivized IAMP practices: Biochar, Cover crops, Conservation crop rotation (>2 crops), Intercropping, Nutrient management (Basic, Enhanced and Precision), Prescribed grazing, Soil carbon amendment.

Sources