Agronomy, Ecology, Evolution and Organismal Biology
Journal or Book Title
Soil Science Society of America Journal
The Conservation Reserve Program (CRP) is a U.S. federal land conservation program that incentivizes grassland reestablishment on marginal lands. While this program has many environmental benefits, two critical questions remain: does reestablishing grasslands via CRP also result in soil health recovery, and what parts of restored fields (i.e. topographic positions) recover the fastest? We hypothesized that soil health will recover over time after converting cropland to CRP grassland, and recovery will be greatest at higher topographic positions. To test this, we sampled 241 Midwest U.S. soils along a grassland chronosequence (0–40 y, including native grasslands) and at four topographic positions – i.e., a chronotoposequence. Soils were measured for bulk density, maximum water holding capacity (MWHC), soil organic carbon (SOC), extractable inorganic nitrogen (N), and potentially mineralizable carbon (PMC) and N. Native grasslands had superior soil health compared to cropland and most CRP soils, and even 40 y since grassland reestablishment was not adequate for full soil health recovery. Topographic position strongly influenced soil health indicators and often masked any CRP effect, especially with MWHC and SOC. However, PMC (a measure of active carbon) responded most rapidly to CRP and consistently across the landscape, and was 26–34% greater 19–40 y after grassland reestablishment. Reestablishing grasslands through CRP can improve soil health, although topographic position regulates the recovery, with greatest improvements at shoulder slope position. Patience is needed to observe changes in soil health, even in response to a drastic management change like conversion of cropland to CRP grassland.
Soil Science Society of America
De, Mriganka; Riopel, Jason A.; Cihacek, Larry J.; Lawrinenko, Michael; Baldwin-Kordick, Rebecca; Hall, Steven J.; and McDaniel, Marshall D., "Soil health recovery after grassland reestablishment on cropland – the effects of time and topographic position" (2019). Ecology, Evolution and Organismal Biology Publications. 386.
Available for download on Saturday, December 12, 2020