Spatial Distribution of Inorganic Nitrogen in Pastures as Affected by Management, Landscape, and Cattle Locus

Abstract

Uneven spatial distribution of soil N in conventionally managed pastures is a function of various biotic and abiotic factors and results in poor land use efficiency. In this study, we measured soil inorganic N (at depths of 0–5, 5–10, and 10–20 cm) in a 50‐m grid and specific areas of interest from eight conventionally managed beef pastures (∼17 ha each), four near Eatonton and four near Watkinsville in the southern Piedmont of Georgia, USA, to assess the effects of management, landscape, and cattle locus in spatial distribution of soil inorganic N. Significant spatial autocorrelation was observed in the soil inorganic N indicating that the regions of high inorganic N deposition were near (within 91 m of) one or more pasture equipage (hay, shade, and water). In the Watkinsville pastures, inorganic N was 65% higher within 5 m of shade than the rest of the pastures, down to a 10‐cm soil depth. In the Eatonton pastures, inorganic N (0–5 cm) was 22% higher within 30 m of a hay‐feeding areas than the rest of the pasture. Cattle locus calculated as cattle density (cow ha−1 yr−1) was a function of pasture equipage and had a significant positive relationship with soil inorganic N. Landscape parameters (slope and elevation) significantly affected inorganic N distribution; however, the effect was small and was masked by management factors. Our results suggest that strategic placement of pasture equipage (hay, shade, and water) can effectively distribute N where needed in beef pastures, thereby increasing land use efficiency. Core Ideas We found uneven spatial distribution of soil inorganic N in conventionally grazed pastures. Management is key to spatial distribution of soil inorganic N. Landscape parameters are important for soil inorganic N distribution. Cattle locus shapes soil inorganic N distribution in pastures.

Strategic Grazing in Beef-Pastures for Improved Soil Health and Reduced Runoff-Nitrate-A Step towards Sustainability

“…Nutrients in the runoff, especially nitrogen and phosphorus, are the leading cause of eutrophication and groundwater contamination [56]. Surface deposition of feces and urine and associated nitrogen in low-lying portions of pastures that have high cattle activity are prone to runoff losses [15,57]. However even with the greater concentration of inorganic N in the 0-5 cm soil layer of the STR system, runoff-nitrate was significantly reduced (from 0.17 to 0.08 kg NO 3 − ha −1 ) which can be attributed to controlled cattle activity in low-lying vulnerable areas, improved ground cover in the AOIs, deeper root growth, and plant utilization of the available nitrogen.…”

“…In the Southeastern USA, we define conventional grazing systems as pastures continuously grazed with little control over grazing time in specific locations within pastures. This results in cattle-preference to certain areas [13,14], leading to uneven nutrient distribution [15,16] and inefficient land utilization. High cattle activity near pasture equipages (water, shade, hay, mineral blocks, etc.)…”

Soil and Land-Use Change Sustainability in the Northern Great Plains of the USA

“…Similarly, other adverse side effects of land-use change are increased greenhouse gas emissions [8,9], reduced water quality [10], and higher soil erosion [11,12]. In the NGP, the adoption of management practices that improve soil health and minimize soil degradation is critical to insure long-term sustainability [13][14][15][16][17][18][19]. We believe that increasing the adoption of sustainable management practices requires a clear understanding of factors driving the land-use change.…”

Soil nitrate leaching under grazed cool‐season grass pastures of the North Central US

“…Management innovations have addressed many of these problems by careful manipulation of livestock distribution with mobile feeding, watering and shading stations combined with the abovementioned adaptive paddock adjustments when herbivory and trampling pressure becomes too high. 25,[31][32][33] However, these practices require daily attention to the pasture resource and must be adopted and implemented to be effective. 34,35 Irrespective of management to homogenize the pressure of livestock on the environment, the distribution of fecal pats and urine patches will always be heterogeneous in pastures at spatial scales where the concentrations of labile N exceed what plants, microbes, and soil organic matter can take up and retain.…”