Impacts of winter grazing on soil health in southeastern cropping systems

Abstract

Coastal Plain soils are often characterized by low soil organic carbon (SOC) as a result of natural and anthropogenic factors. A rotation of cotton (Gossypium hirsutum L.) and peanut (Arachis hypogaea L.) under conventional tillage is typical in this region, but an opportunity to increase SOC and improve soil health by incorporating winter grazing of cover crops exists for producers with row crop and livestock operations. A study to assess winter grazing impacts on soil health was established in the U.S. Coastal Plain. Three cattle removal dates and an ungrazed control were evaluated for impacts on selected soil health indicators: SOC, permanganate oxidizable carbon (POXC), water stable aggregates (WSA), penetration resistance (PR), microbial biomass C (MBC), and arbuscular mycorrhizal fungi (AMF) colonization rates.After two years, MBC was highest in the control treatments, likely due to greater cover crop biomass on the soil surface at termination. No differences were observed between treatments for SOC, POXC, WSA, PR, or AMF. Increased cotton lint yield was observed in control and mid-February treatments in 2019, likely due to greater cover crop residues on the soil surface following grazing, which may have conserved soil moisture during the growing season. Peanut yields were unaffected by treatments in 2020. Lack of differences in soil health indicators suggests that integrating wintergrazing livestock does not negatively nor positively impact selected dynamic soil properties in the short-term, but more time under grazing treatments is needed to thoroughly evaluate how winter-grazing livestock impacts soil health and crop yield.

Impact of cattle grazing corn residue in spring on soil and subsequent soybean yield

“…Of 11 studies evaluating impacts of cover crop or annual forage grazing, six studies reported increases in bulk density in the upper 10 cm (Bonetti et al., 2019; Franzluebbers & Stuedemann, 2008; George et al., 2013; Kelly et al., 2021; Tobin et al., 2020; Tollner et al., 1990), with the remaining five reporting no effect (Anderson et al., 2021; Blanco‐Canqui et al., 2020; Dhaliwal & Kumar, 2021; Hill et al., 2004; Simon et al., 2021). Of 10 studies reporting penetration resistance, five reported increases (Dhakal et al., 2022; Franzluebbers & Stuedemann, 2008; Mullins & Burmester, 1997; Schomberg et al., 2021; Tollner et al., 1990) and four reported no effect (Anderson et al., 2021; Blanco‐Canqui et al., 2020; Crowell et al., 2021; Dhaliwal & Kumar et al., 2021; Tracy & Zhang, 2008). It is also important to note that the majority of these studies did not report increases in bulk density or penetration resistance that would be expected to limit root penetration and thus impact crop production.…”

“…Of 10 studies reporting penetration resistance, five reported increases (Dhakal et al, 2022;Franzluebbers & Stuedemann, 2008;Mullins & Burmester, 1997;Schomberg et al, 2021;Tollner et al, 1990) and four reported no effect (Anderson et al, 2021; T A B L E 4 Soybean emergence and grain yield (87% DM) when planted after corn residue was either not grazed grazed in early spring prior to soybean planting a at a normal stocking density (NSD) with 7.5 steers/ha for 45 days or at a high stocking density (HSD) with 22.5 steers/ha for 15 days. Blanco -Canqui et al, 2020;Crowell et al, 2021;Dhaliwal & Kumar et al, 2021;Tracy & Zhang, 2008). It is also important to note that the majority of these studies did not report increases in bulk density or penetration resistance that would be expected to limit root penetration and thus impact crop production.…”

“…These differences may be due to differences in the soil moisture at the time of grazing or the number of wet-dry cycles between grazing and measurements. Of 14 studies that measured impacts of grazing cover crops and reporting cash crop yields, nine reported no effect on crop yield (Anderson et al, 2021;Blanco-Canqui et al, 2020;Bourgault et al, 2021;Hill et al, 2004;Kelly et al, 2021;Tobin et al, 2020;Tollner et al, 1990;Tracy & Zhang, 2008;Peterson et al, 2019), one reported an improvement (George et al, 2013) and five reported mixed effects (Crowell et al, 2021;Dhakal et al, 2022;Franzluebbers & Studemann, 2013;Mullins & Burmester, 1997;Schomberg et al, 2014). Within the studies that reported mixed effects, the impacts of biomass removal on soil moisture may play a major role.…”

Rye planting date impacts biomass production more than seeding rate and nitrogen fertilizer

“…This difference between N rates was only observed at the surface, although the SOC concentration ratio decreased with depth, particularly past the 5–10 cm zone. Numerous studies have shown an increase in SOC concentrations near the soil surface due to stratification of SOC with depth in conservation systems (Balkcom et al., 2013; Crowell et al., 2022; Franzluebbers, 2021; Novak et al., 2009).…”

Farming with forages can reconnect crop and livestock operations to enhance circularity and foster ecosystem services

“…Grazing of cover crops can have mixed effects on subsequent crop yield. Sometimes a negative impact of cover crop grazing occurs on subsequent cash crop yield, perhaps due to exposure of soil to enhanced water evaporation (Crowell et al, 2022; Franzluebbers & Stuedemann, 2007). Greater subsequent crop growth has also been attributed to enhanced fertility status with greater soil organic matter (George et al, 2013).…”