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

Based on the definitions below taken from the COMET model, the field has been farmed using 'Intensive tillage' practices (>> 15% of residue maintained) and will now be farmed using one of the reduced tillage practices in the table below with at least 30% crop residue remaining after tillage.

Tillage Class	Tillage Definition	Tillage Implements Used (specific implement to be specified in contract)
Intensive Tillage	Little to no (>>15%) crop residue remains on the surface after tillage.	Moldboard Plow followed by Field Cultivator and/or Tandem Disk
Reduced Tillage	15-30% of crop residue remains on the surface after tillage.	Point Chisel followed by Tandem Disk or multiple passes of a Tandem Disk
Mulch Tillage	30% or more of crop residue remains on the surface after tillage.	Single Pass with a Tandem Disk followed by Field or Row Cultivator or similar implement
Ridge Tillage	30% or more of crop residue remains on the surface after tillage.	No-till or Strip-till Planter followed by a Field Cultivator or Row Cultivator or similar implement
Strip Tillage	75% or more of crop residue remains on the surface after tillage.	No-till or Strip-till Planter plus a somewhat lighter Field/Row Cultivator implement pass

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.