Theme 1: Grassland Ecology
Description
Grasslands are expected to deliver ecosystem services by sequestering soil organic C, improving soil health and water quality, and minimizing soil erosion. Data to support these ecosystem services from contemporary managed grasslands are relatively scant, and so on-farm measurements would help bolster assessment across more diverse environmental settings. This study was conducted to compare soil properties from paired landuse of croplands and grasslands in a diversity of Major Land Resource Areas – the Piedmont, Blue Ridge, and Blackland Prairie of the southeastern USA. Four separate pastures on three collaborating farms were sampled at depth of 0-10 cm. Four samples from a neighboring cropland field were paired with these pastures. A variety of soil chemical, physical, and biological properties were determined. Soil chemical properties were occasionally different between land management systems on one of the three farms, but few consistent differences occurred across farms. Dry-stable mean-weight diameter (MWD) was not different between paired land management systems, but water-stable MWD was dramatically reduced at all three locations with cropland compared with pasture. Soil stability index (water-stable MWD divided by dry-stable MWD) averaged 0.64 mm mm-1 under cropland and 0.91 mm mm-1 under pasture, suggesting that pastures had a highly stable soil surface that was resistant to erosion and likely contributed to high water infiltration. Soil organic C and N fractions (i.e., total, particulate, and mineralizable) were all significantly greater under pasture than under cropland, indicating that these pastures were indeed storing more C and N, and contributing to greater soil biological activity. This study provides evidence that well-managed grasslands can sequester soil organic C and N, improve soil surface stability conditions to foster water infiltration and reduced runoff, and may have important implications for habit development for soil-dwelling organisms.
DOI
https://doi.org/10.13023/2ebj-tb51
Citation
Franzluebbers, Alan J.; van Vliet, S.; and Poore, M. H., "Surface-Soil Aggregation and Organic C and N Fractions Under Paired Grassland and Cropland Sites in the Southeastern USA" (2023). IGC Proceedings (1993-2023). 30.
https://uknowledge.uky.edu/igc/XXV_IGC_2023/Ecology/30
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Surface-Soil Aggregation and Organic C and N Fractions Under Paired Grassland and Cropland Sites in the Southeastern USA
Grasslands are expected to deliver ecosystem services by sequestering soil organic C, improving soil health and water quality, and minimizing soil erosion. Data to support these ecosystem services from contemporary managed grasslands are relatively scant, and so on-farm measurements would help bolster assessment across more diverse environmental settings. This study was conducted to compare soil properties from paired landuse of croplands and grasslands in a diversity of Major Land Resource Areas – the Piedmont, Blue Ridge, and Blackland Prairie of the southeastern USA. Four separate pastures on three collaborating farms were sampled at depth of 0-10 cm. Four samples from a neighboring cropland field were paired with these pastures. A variety of soil chemical, physical, and biological properties were determined. Soil chemical properties were occasionally different between land management systems on one of the three farms, but few consistent differences occurred across farms. Dry-stable mean-weight diameter (MWD) was not different between paired land management systems, but water-stable MWD was dramatically reduced at all three locations with cropland compared with pasture. Soil stability index (water-stable MWD divided by dry-stable MWD) averaged 0.64 mm mm-1 under cropland and 0.91 mm mm-1 under pasture, suggesting that pastures had a highly stable soil surface that was resistant to erosion and likely contributed to high water infiltration. Soil organic C and N fractions (i.e., total, particulate, and mineralizable) were all significantly greater under pasture than under cropland, indicating that these pastures were indeed storing more C and N, and contributing to greater soil biological activity. This study provides evidence that well-managed grasslands can sequester soil organic C and N, improve soil surface stability conditions to foster water infiltration and reduced runoff, and may have important implications for habit development for soil-dwelling organisms.
