Persistence and quality of vegetation cover in expired Conservation Reserve Program fields

Abstract

For nearly 40 years, the Conservation Reserve Program (CRP) has implemented practices to reduce soil erosion, improve water quality, and provide habitat for wildlife and pollinators on highly erodible cropland in the United States.However, an approximately 40,470 ha (10 million acres) decline in enrolled CRP land over the last decade has greatly reduced the program's environmental benefits. We sought to assess the program's enduring benefits in the central and western United States by (1) determining the proportion of fields that persist in CRP cover after contracts expired, (2) identifying the type of agricultural production that CRP fields shift to after contract expiration, (3) comparing the vegetation characteristics of expired CRP fields that are persisting in CRP-type cover with enrolled CRP fields, and (4) identifying differences in management activities (e.g., haying, grazing) between expired and enrolled CRP fields. We conducted edge-of-field vegetation cover surveys in 1092 CRP fields with contracts that expired ≥3 years prior and 1786 currently enrolled CRP fields in 14 states. We found that 41% of expired CRP fields retained at least half of their area in CRP-type cover, with significant variation in persistence among regions ranging from 19% to 84%. When expired fields retained CRP vegetation, bare ground was low in all regions and grass cover was somewhat greater than in fields with current CRP contracts, but at the expense of forb cover in some regions. Evidence of more frequent management in expired CRP fields may explain differences between active and expired CRP fields. Overall, there is clear evidence that CRP-type cover frequently persists and provides benefits for more than three years after contract expiration. Retaining CRP-type cover, post-contract, is an under-recognized program benefit that persists across the central and western United States long after the initial retirement from cropland.

Soil climate underpins year effects driving divergent outcomes in semi-arid cropland to grassland restoration

“…As of 2020 there were 8.9 million hectares enrolled, with the Western Great Plains region having the greatest enrollment (USDA, 2023). Landowners follow state-or regional-level guidelines for seed application (Taliga, 2011), often with restored plant communities remaining even after CRP payments have ceased (Vandever et al, 2023).…”

Antecedent climate explains divergent, long-term restoration outcomes in the Western Great Plains, USA.

“…Landowners typically follow state-or regional-level guidelines that adhere to national prescriptions for seed application (Taliga, 2011). Often, the plant community established by CRP remains on the land with all of its associated benefits even after contracts expire (Vandever et al, 2023). Successful establishment of perennial vegetation under the CRP program has been shown to increase soil microbial function (Li et al, 2018) and biomass (Bach, Baer and Six, 2012), preserve freshwater ecosystem services (Huang et al, 2019), improve pollinator health (Ricigliano et al, 2019), and increase soil carbon mineralization (Bach, Baer and Six, 2012).…”