Grassland set-asides (GLSA) are agricultural fields that are planted to a grass/legume mixture and are left to grow for a period up to six years. Set-asides provide dense tall-grass vegetative cover, which alleviate some impacts of soil degradation and build soil organic matter.
In addition to being used to remediate continuously cultivated soils, GLSAs also provide essential wildlife habitat for birds of prey, which congregate in the tens of thousands every winter in Delta. Less than 10 per cent of the original tall grass habitat that directly supports these bird species remains throughout Delta.
To encourage the incorporation of GLSAs into crop rotations, Delta Farmland & Wildlife Trust (DF&WT) has administered a GLSA Stewardship Program for over 20 years. The program provides a cost-share to farmers to support this sustainable land management practice, which assists with the costs of temporarily taking land out of agricultural production.
DF&WT is a non-profit organization that works in partnership with local farmers to conserve soil and wildlife resources on the lower Fraser River delta.
In 2015, DF&WT in partnership with the University of British Columbia’s Faculty of Land and Food Systems began a five-year research project with federal funding delivered by Investment Agriculture Foundation of BC. The project is evaluating the effects of short (two-year) to medium (four-year) term recurrent GLSAs on enhancing soil quality. Results will assist farmers in optimizing the management of their set-asides and will ultimately contribute to sustaining agriculture as a viable industry in Delta for the foreseeable future.
Four master’s students are examining the impacts of GLSAs on select soil properties. This includes the effects of GLSAs on soil quality, and how the incorporation of a GLSA into a crop rotation affects soil nutrient cycling and subsequent crop yield. How these effects on soil quality, nutrient cycling and crop yields vary with duration of the set-aside is also being examined.
Results to date have found that after two years GLSAs improve soil structure. Impacts of GLSAs on soil nutrient cycling support that three-year-old set-asides can potentially improve nitrogen availability; however, results were inconsistent due to a number of different variables. Preliminary results evaluating the impacts of GLSAs on crop yield found 40 to 70 per cent increases in yield compared to a control with no GLSA. Results thus far support the benefits of GLSAs for soil conservation and improving soil productivity.
Learn more about the GLSA Stewardship Program and the many benefits it provides for both soil and wildlife conservation at DF&WT’s 13th annual Day at the Farm agricultural awareness event on Saturday, Sept. 8 from 10 a.m. to 4 p.m. at the Westham Island Herb Farm.