There are many variables that determine the success of a crop and crop rotations can be used to maintain and manage nutrient and moisture levels in the soil.
Anne Paquette is a masters candidate at the University of Saskatchewan whose thesis is focused on water use efficiency. Research typically shows increased water use efficiency of peas, meaning there is still good yield in dry years. She says they did observe this, but at some sites factors such as salinity overpowered the pea’s ability to overcome a lack of moisture.
In the video below, Paquette dives in to the difference between shallow and deep rooted crops. Deep rooted plants, such as wheat and canola for example, penetrate further into the soil to account for a lack of water at the surface. Deep rooted plants deplete soil water for the next crop. Peas are a shallow rooted crop; they take up water at the surface. Overall, shallow rooted crops take up less water and are able to leave behind moisture for deep rooted crops.
The last few years have shown unique drought conditions, well-suited to researching water use efficiency. Paquette says with the significant drought in 2021 followed up by more drought conditions in 2022, they did not see the deep soil water build up after pea growth. Due to the depleted soil water in drought conditions the peas took up all water provided by precipitation. This finding brought Paquette to the conclusion that there are limits to the amount of soil water restored by pea crops.
Adding peas into rotation is beneficial to water use efficiency. Paquette says peas overall use less soil moisture and increase yields in a rotation.