Long‐term effects of grazing management and buffer strips on phosphorus runoff from pastures fertilized with poultry litter

Abstract

Phosphorus (P) runoff from pastures can cause accelerated eutrophication of surface waters. However, few long‐term studies have been conducted on the effects of best management practices, such as rotational grazing and/or buffer strips on P losses from pastures. The objective of this study was to evaluate the long‐term effects of grazing management and buffer strips on P runoff from pastures receiving annual (5.6 Mg ha−1) poultry litter applications. A 14‐yr study was conducted on 15 small watersheds (0.14 ha) with five treatments: hayed (H), continuously grazed (CG), rotationally grazed (R), rotationally grazed with an unfertilized buffer strip (RB), and rotationally grazed with an unfertilized fenced riparian buffer (RBR). Runoff samples were collected using automatic samplers during runoff events. Average annual runoff volumes from H (40 mm yr−1) and RBR (48 mm yr−1) were lower than CG and RB, which were both 65 mm yr−1, and from R (67 mm yr−1). Rotational grazing alone did not reduce P loads compared with continuous grazing (1.88 and 1.71 kg P ha−1 for R and CG, respectively). However, compared with CG, total P losses from RB pastures were reduced 36% with unfertilized buffer strips (1.21 kg P ha−1), 60% in RBR watersheds with unfertilized fenced riparian buffer strips (0.74 kg P ha−1), and 49% by converting pastures to hayfields (0.97 kg P ha−1). Hence, the use of unfertilized buffer strips, unfertilized fenced riparian buffer strips, or converting pastures to hayfields are effective best management practices for reducing P runoff in U.S. pasture systems.

Selecting soil hydraulic properties as indicators of soil health: Measurement response to management and site characteristics

“…Likewise, Anderson et al. (2020) found that increased runoff volumes led to significant increases in P runoff. Some studies have found that D b is not changed by tillage (Khaledian et al., 2012; Strudley et al., 2008), making it important to investigate interactions between soil management and other drivers of variance in D b .…”

“…Pilon et al (2017) found that increases in bulk density due to grazing from cattle resulted in higher runoff volumes from pastures and increased soil erosion. Likewise, Anderson et al (2020) found that increased runoff volumes led to significant increases in Water stable aggregate percentage (WSA), bulk density (D b ), permanent wilting point (θ PWP ), field capacity measured on repacked (θ FC_REPACK ) and intact (θ FC_INTACT ) cores, saturated hydraulic conductivity (K S ), and soil organic carbon (SOC) P runoff. Some studies have found that D b is not changed by tillage (Khaledian et al, 2012;Strudley et al, 2008), making it important to investigate interactions between soil management and other drivers of variance in D b .…”

Long-term impacts of conservation pasture management in manuresheds on system-level microbiome and antibiotic resistance genes

“…The field setup utilized 15 sloped and individually isolated manuresheds at the USDA-ARS Research Center in Booneville, Arkansas that have been previously described ( Pilon et al, 2017a , b , 2019 ; Anderson et al, 2020 ; Yang et al, 2021 ) ( Supplementary Figure S2 ). Three different agricultural conservation management practices were evaluated, including rotationally grazed (R), rotationally grazed with a buffer strip (RB), and rotationally grazed with a fenced riparian buffer (RBR).…”

Utility of Plant Growth-Promoting Rhizobacteria for Sustainable Production of Bermudagrass Forage

“…Off-site movement of fertilizers and excess Microorganisms 2023, 11, 863 2 of 13 nutrient applications have led to issues such as soil salinity, heavy metal accumulation, water eutrophication, and accumulation of nitrates [8]. In grazed pastures, phosphorus runoff can cause water eutrophication in both coastal and freshwater systems [9]. Some coastal areas in the United States have already began implementing restrictions on fertilizer applications [10].…”