Grain and Legume Intercropping in Short-Season Organic No-Till Transition

Commodities

• Agronomic: peas (field, cowpeas), wheat, other

Practices

• Crop Production: intercropping, no-till
• Education and Training: youth education

Organic no-till systems are management intensive. Transitioning to no-till without herbicides requires the successful establishment of dense cover crop stands with effectively timed termination. The altitude, short frost-free season, low degree days, limited precipitation and degraded soils of the Intermountain West pose challenges for cover crop establishment in the same season as cash crop production.

What system of cover crimping or tillage best reduces weed pressure in the transition to organic no-till when adapted to a short season under flood irrigation? Will intercropping wheat with legumes provide overall higher cash crop yields and better weed suppression than monocrop wheat? What effect will these various approaches have on soil health and input costs?

Research plots will be 2 to 3 acres in a transition to no-till with: 1) a fall-planted rye cover, crimped and late spring planted to a wheat / lentil intercrop; 2) a fall rye cover, crimped and late planted to a wheat / field pea intercrop; 3) a fall rye cover, crimped and late planted to a wheat / bolita bean; and 4) a fall rye cover crimped and late planted to a wheat monocrop. The 4 cropping regimes will be replicated with the cover tilled and planted in early spring .

The same limiting factors that deter adoption of organic no-till have the most potential to improve from the practice: with increased organic matter, biological activity, irrigation efficiency, and reduced field operations. Fragile high desert soils can benefit the most from reduced tillage. The project has potential significance beyond the region, as agricultural production elsewhere is increasingly prone to drought and unstable climate. If organic no-till can be achieved at scale in this austere environment, it can be practiced almost anywhere.

Results will be disseminated to stakeholders primarily through hands-on intensives, published materials, and media outlets.

The research objectives are:

1. Identify if mono-cropping wheat, or intercropping wheat with lentils, field peas or bolita beans provides the greatest reduction in weed populations in transition to organic no-till;
2. Identify if intercropping wheat with lentils, field peas or bolita beans provides a land equivalent ratio yield or quality advantage over monocrop wheat in transition to organic no-till;
3. Identify if fall-planted rye cover crimped and late spring planted to cash crop, or cover tillage in spring with early planting provides the greatest reduction in weed populations in transition to organic no-till;
4. Identify if fall-planted rye cover crimped and late spring planted to cash crop, or cover tillage in spring with early planting provides the greatest improvement in LER cash crop yield and quality in transition to organic no-till;
5. Identify which combination of the above approaches provides the greatest improvement in soil organic matter, soil aggregation, erosion, water infiltration, soil nutrient availability, and soil microbial activity in transition to organic no-till; and
6. Perform a cost / benefit analysis of each approach over the performance period.

The education objectives are:

1. Share Knowledge on No-Till Practices and Intercropping Systems
2. Increasing Visibility of Small Grain Production in Taos County
3. Engage Future Producers In Regenerative Practices