Tall fescue management and environmental influences on soil, surface residue, and forage properties

Environmental characteristics within a region often form site-specific agro-ecological responses to management. Using 92 fall-stockpiled tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] field trials in North Carolina and surrounding states, our objective was to test the influence of two management factors (forage utilization and pasture age) and two environmental factors (elevation and soil textural gradients) on soil properties at 0-to-10-cm depth, surface residue carbon (C) and nitrogen (N) contents, and absolute forage mass and nutritive values and their responses to N fertilization. Soil organic C and N fractions (i.e., total, particulate, and mineralizable) were greater (a) with improved (rotational stocking) than conventional (haying and/or continuous grazing) forage utilization, (b) in older pastures, (c) at higher elevation, and (d) with finer texture. Soil chemical properties were variably affected by these factors, and soil-test P was not affected. Surface residue N tended to be greater with improved than conventional forage utilization, but surface residue C was not affected by any of the factors. Crude protein was greater and dry matter yield response to N fertilizer was lower with improved than with conventional forage utilization. Forage mass was lower and nutritive values were greater at higher elevation. Soil organic C and total soil N sequestration rates during a 25-yr period were 0.75 Mg C ha(-1) yr(-1) and 75 kg N ha(-1) yr(-1), respectively. Elevation and soil texture imparted strong environmental controls on a diversity of soil properties, but management factors mostly affected surface-soil organic C and N fractions, which helped sustain forage productivity and nutritive value with lower N fertilizer input.

Automated summary

Environmental characteristics have significant impacts on soil properties and forages, with elevation and soil texture playing a crucial role in shaping soil characteristics. Improved forage utilization and rotational grazing were found to be more beneficial for accumulation of soil organic C and N, as well as sustaining forage productivity and nutritive value.