Location: Small Grain and Food Crops Quality Research
Project Number: 3060-21650-002-058-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 15, 2024
End Date: Dec 31, 2025
Objective:
The aim of this study is to address these key research gaps by investigating the impacts of WP inclusion and compost inputs on soil health, soil microbiome, soil carbon sequestration, CO2 emissions, and weed dynamics. This is a 2-year project with the following specific objectives, 1) Assessing the long-term impacts of integrating winter peas into dryland wheat-fallow systems on soil carbon sequestration, carbon emissions, and soil health indicators at low and intermediate rainfall zones of eastern Washington, 2) Determining interactive effects of integrating compost and winter peas into wheat-fallow systems on soil carbon, soil health, and crop performance, and 3) Investigate the long-term influence of cereal-legume crop rotations and integrating compost on weed dynamics, crop performance, moisture use, and grain quality in eastern Washington.
Approach:
To accomplish the objectives, two ongoing long-term trials in Davenport, WA and Ritzville, WA will be used. The trial at Davenport involves varying rates of compost application in winter wheat-fallow and winter wheat-fallow-winter pea-fallow rotations. The trial at Ritzville was established in 2010 to compare two 3-year rotations; (i) winter pea-spring wheat-fallow (WP-SW-F) and (ii) winter wheat-spring wheat-fallow (WW-SW-F). Soil sampling from both trials will be conducted from 0-10 and 10-30 cm depths in spring 2025 and 2026, and analyzed for a suite of soil physical, chemical, and biological indicators. Soil samples from both trials will also be analyzed for carbon fractions and CO2 emissions. Weed seed bank samples will also be collected from 0-10 and 10-20 cm in spring 2025 and 2026. Microbial community structure will be analyzed for soil samples from 0-10 cm depth using phospholipid fatty acid (PLFA) and neutral lipid fatty acid (NLFA) analyses. Data generated from our study and both long-term trials will not only address the key knowledge gaps but also promote growers to incorporate legumes and other conservation management practices, thus, making regional cropping systems economically and environmentally more sustainable and enhance soil carbon sequestration.
