Theme 1: Grassland Ecology
Description
. Optimizing soil health requires building an environment that creates conditions which allow for best function of the chemical, biological, and physical properties of the soil to thrive as an organism and an ecosystem. Integrated crop-livestock systems (ICLS) use a systems approach to provide improvements to soil health parameters. In the fall of 2021, a randomized complete block study was conducted at the Coastal Plain Branch Experiment Station (CPBES) in Newton, Mississippi and at the Prairie Research Unit (PRU) in Prairie, Mississippi to observe the soil health effects of grazing cereal rye cover crops in a soybean production system. Three treatments were replicated three times across nine paddocks at each location. Treatments included: conventional soybean production respective for each location (CS); cereal rye established as a cover crop for a no-till soybean system (CC); and cereal rye established as a cover crop for a notill soybean system and grazed (GC). Soil health was measured by soil sample analysis and forage production. Soil samples were evaluated for soil respiration, total carbon (TC), nitrogen (N), phosphorus (P), and potassium (K). All paddocks were stocked at approximately 2000 lb ac1 using replacement beef heifers. Forage samples were collected throughout grazing periods and were analyzed for forage mass (FM) and nutritive value (crude protein – CP, total digestible nutrients - TDN) using near-infrared spectroscopy (NIRS). Mean FM from CG paddocks was 999 lb DM ac-1 at CPBES compared to 705 lb DM ac-1 at PRU. CP concentration was 25.6% from CPBES and 15.8% from PRU. Mean TDN was 56.3% at CPBES compared to 57.5% at PRU. Change in mean soil respiration from pre-grazing to post grazing at CPBES was 0.327mg CO2/g soil, 0.308 mg CO2/g soil, and 0.464 mg CO2/g soil in CS, GC, and CC treatments respectively. Change in mean soil respiration from pre-grazing to post grazing at PRU was -0.159 mg CO2/g soil, -0.034 mg CO2/g soil, and -0.072 mg CO2/g soil in CS, GC, and CC treatments respectively. Total carbon mean differences were 0.791mg C/kg soil, 0.953mg C/kg soil, and 1.01mg C/kg soil in CS, GC, and CC treatments at CPBES and were 0.595mg C/kg soil, 0.438mg C/kg soil, and 0.476mg C/kg soil in CS, GC, and CS treatments at PRU. Changes in mean N, P, and K were 0.06 mg N/kg soil, -12.141 mg P/kg soil, and 34.555mg K/kg soil at CPBES and 0.052 mg N/kg soil, 0.518 mg P/kg soil, and 17.409 mg K/kg soil at PRU in CS treatments, 0.082 mg N/kg soil, -3.899 mg p/kg soil, and 29.699 mg K/kg soil at CPBES, 0.032 mg N/kg soil, 0.325 mg P/kg soil, and 9.877 mg K/kg soil at PRU in GC treatments, and 0.082 mg N/kg soil, -3.217 mg P/kg soil, and 36.767 mg K/ kg soil at CPBES, 0.041 mg 0.357 mg P/kg soil, and 7.267 mg K/kg soil at PRU in CC treatments. Differences in nutrient concentrations can be attributed to nutrient cycling of residue from previous growing season and nutrient cycling from grazing heifers. A second year of grazing combined with additional soil sample analysis will help determine the effects grazing a cereal rye cover crop has on soil health of two distinct soils in eastern Mississippi.
DOI
https://doi.org/10.13023/zp2m-mb41
Citation
Davis, Forrest E. and Rushing, J. Brett, "Grazing Cover Crops for Soil Health in an Integrated Crop-Livestock System" (2023). IGC Proceedings (1993-2023). 22.
https://uknowledge.uky.edu/igc/XXV_IGC_2023/Ecology/22
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Grazing Cover Crops for Soil Health in an Integrated Crop-Livestock System
. Optimizing soil health requires building an environment that creates conditions which allow for best function of the chemical, biological, and physical properties of the soil to thrive as an organism and an ecosystem. Integrated crop-livestock systems (ICLS) use a systems approach to provide improvements to soil health parameters. In the fall of 2021, a randomized complete block study was conducted at the Coastal Plain Branch Experiment Station (CPBES) in Newton, Mississippi and at the Prairie Research Unit (PRU) in Prairie, Mississippi to observe the soil health effects of grazing cereal rye cover crops in a soybean production system. Three treatments were replicated three times across nine paddocks at each location. Treatments included: conventional soybean production respective for each location (CS); cereal rye established as a cover crop for a no-till soybean system (CC); and cereal rye established as a cover crop for a notill soybean system and grazed (GC). Soil health was measured by soil sample analysis and forage production. Soil samples were evaluated for soil respiration, total carbon (TC), nitrogen (N), phosphorus (P), and potassium (K). All paddocks were stocked at approximately 2000 lb ac1 using replacement beef heifers. Forage samples were collected throughout grazing periods and were analyzed for forage mass (FM) and nutritive value (crude protein – CP, total digestible nutrients - TDN) using near-infrared spectroscopy (NIRS). Mean FM from CG paddocks was 999 lb DM ac-1 at CPBES compared to 705 lb DM ac-1 at PRU. CP concentration was 25.6% from CPBES and 15.8% from PRU. Mean TDN was 56.3% at CPBES compared to 57.5% at PRU. Change in mean soil respiration from pre-grazing to post grazing at CPBES was 0.327mg CO2/g soil, 0.308 mg CO2/g soil, and 0.464 mg CO2/g soil in CS, GC, and CC treatments respectively. Change in mean soil respiration from pre-grazing to post grazing at PRU was -0.159 mg CO2/g soil, -0.034 mg CO2/g soil, and -0.072 mg CO2/g soil in CS, GC, and CC treatments respectively. Total carbon mean differences were 0.791mg C/kg soil, 0.953mg C/kg soil, and 1.01mg C/kg soil in CS, GC, and CC treatments at CPBES and were 0.595mg C/kg soil, 0.438mg C/kg soil, and 0.476mg C/kg soil in CS, GC, and CS treatments at PRU. Changes in mean N, P, and K were 0.06 mg N/kg soil, -12.141 mg P/kg soil, and 34.555mg K/kg soil at CPBES and 0.052 mg N/kg soil, 0.518 mg P/kg soil, and 17.409 mg K/kg soil at PRU in CS treatments, 0.082 mg N/kg soil, -3.899 mg p/kg soil, and 29.699 mg K/kg soil at CPBES, 0.032 mg N/kg soil, 0.325 mg P/kg soil, and 9.877 mg K/kg soil at PRU in GC treatments, and 0.082 mg N/kg soil, -3.217 mg P/kg soil, and 36.767 mg K/ kg soil at CPBES, 0.041 mg 0.357 mg P/kg soil, and 7.267 mg K/kg soil at PRU in CC treatments. Differences in nutrient concentrations can be attributed to nutrient cycling of residue from previous growing season and nutrient cycling from grazing heifers. A second year of grazing combined with additional soil sample analysis will help determine the effects grazing a cereal rye cover crop has on soil health of two distinct soils in eastern Mississippi.
