Using native rhizobia to create a drought-resilient field pea production system

View the project final report

Commodities

• Agronomic: peas (field, cowpeas)

Practices

• Crop Production: biological inoculants, crop improvement and selection, fertilizers, nutrient cycling, nutrient management, varieties and cultivars
• Education and Training: demonstration, extension, on-farm/ranch research
• Production Systems: dryland farming

Legumes such as field peas have emerged as a viable option for farmers to diversify their cropping rotations. An added benefit of legumes in rotation is their ability to fix nitrogen through a symbiotic relationship with rhizobia bacteria. The nitrogen fixed by this interaction not only helps the legume crop, but also the subsequent crop as the fixed nitrogen is released to the soil as legumes decompose at the end of the season. This process allows farmers to be less reliant on expensive nitrogen fertilizers for both crops. However, as field peas continue to expand into the northern Plains, where dry, hot summers are common, it is evident that heat and drought stress are major limiting factors to both production and adoption by farmers. The problem of drought stress is two-fold in that it not only affects yield, but it also severely limits nitrogen fixation by rhizobia.

It is possible that native rhizobia, acclimated to the local climate and soils, are more effective at nitrogen fixation under stress conditions. This project intends to 1) examine the paired use of drought tolerant field peas and native rhizobia versus commercial rhizobia to maintain nitrogen fixation in field peas during drought stress, 2) identify the most effective inoculation methods for nitrogen fixation, and 3) create an open-source culture method that farmers can utilize on their own farms to be used as either a standalone inoculant or in combination with commercial inoculant.

Project Outcomes

1) Evaluate the use of native rhizobia to maintain nitrogen fixation in field peas during drought stress and improve crop performance

2) Identify the most drought tolerant FP varieties and the most effective inoculation methods for nitrogen fixation in field peas and ensure that farmers are employing these techniques

3) Educate farmers on the value of effective nitrogen fixation and the importance of legumes in diversified cropping rotations

4) Create an open-source culture method that farmers can utilize on their own farms to be used as either a standalone inoculant or in combination with commercial inoculants