Abstract
Short-term grassland set-asides (GLSA) have been incorporated into intensive annual crop rotations to improve soil quality. The legacy of the GLSA to subsequent annual crops, however, is not well understood. The objective of this study was to determine the impacts of 3-year-old GLSA on nitrogen (N) dynamics and the yield of the subsequent cash crop. A regional analysis was conducted over two years, utilizing eight production fields transitioning from GLSA, paired with fields in continuous annual crop rotation (ACR) with matching management. A controlled plot-scale experiment was also conducted on a single 3-year-old GLSA, comparing fertilizer types, rates, and timing of incorporation. In each experiment, soils were sampled every 10–14 days for ammonium (NH4+-N) and nitrate (NO3−-N), along with ion probes, installed near the rooting zone to track plant available nitrogen (PAN) throughout the season. The results from the regional analysis are confounding, in 2015 showing that GLSA supplied an additional 18 kg PAN ha−1 compared to ACR but showed no PAN benefits in 2016. The controlled plot-scale experiment highlighted the importance of fertilizer type to subsequent PAN, showing synthetic treatments consistently supplied more PAN than organic. The results from this study suggest that 3-year-old GLSAs can potentially improve PAN to subsequent crops depending on how they are managed.
Highlights
Grassland set-asides (GLSA), known as grassland-arable rotations and grass-leys, are a management scheme that replaces crop production on arable land with perennial grasses for various economic and ecological purposes [1]
Ion exchange probes, which tracked cumulative plant available nitrogen (PAN) supply, corroborated seasonal trends, with a higher PAN supply from GLSA than annual crop rotations (ACR) in 2015, and less in 2016. These results show that PAN mineralization may peak later in the season in GLSA compared to the ACR, the GLSA can still contribute to a higher seasonal average PAN, or GLSA may reduce PAN
We found that a substantial amount of N was added to GLSA fields through the incorporation of aboveground biomass (AGB) ranging from 86 to 101 kg ha−1 over both seasons
Summary
Grassland set-asides (GLSA), known as grassland-arable rotations and grass-leys, are a management scheme that replaces crop production on arable land with perennial grasses for various economic and ecological purposes [1]. In Canada, three GLSA programs have been utilized since 1988, to control soil erosion as well as create bird habitat Of these three programs, only one remains operational today—the GLSA stewardship program offered by the Delta Farmland and Wildlife Trust (DF&WT), a non-governmental organization in the Fraser River Delta of British Columbia (BC). Only one remains operational today—the GLSA stewardship program offered by the Delta Farmland and Wildlife Trust (DF&WT), a non-governmental organization in the Fraser River Delta of British Columbia (BC) This program provides cost-share payments to farmers for taking active agricultural land out of production and seeding it with a mix of grasses and legumes for a period of one to four years [4]. The main goals of Agronomy 2020, 10, 1382; doi:10.3390/agronomy10091382 www.mdpi.com/journal/agronomy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
