Soil health under forage and grazing lands in the humid United States

Abstract

Soil health describes critical functions that can be influenced by land management. Some key soil characteristics are inherent and not altered appreciably, such as texture, mineralogy, and landscape position. Other soil properties and processes can be changed by land management, such as soil organic matter, nutrient concentrations, and the capacity to infiltrate and store water. How and when forage and grazing lands are harvested can modify photosynthesis and allocation of carbon to roots and exudates in soil. Grazing intensity, characterized primarily by stocking rate, is a key management strategy that alters cycling of carbon (C) and associated plant nutrients. Stocking method, nutrient amendment (source, timing, and rate), forage utilization strategy, season of grazing/deferment, type and class of livestock, and livestock distribution on the landscape are other important management strategies that can either negatively affect compaction, nutrient concentration, and greenhouse gas emissions or stimulate greater water holding capacity, slow and steady cycling of nutrients, and soil C and nitrogen (N) sequestration. Responses of soil health to pasture management can be effectively characterized by its essential functions: (i) producing plants for food and fiber, (ii) cycling nutrients, (iii) storing organically bound elements like C and N, (iv) protecting water quality, (v) supplying water and plant growth–promoting compounds, (vi) enabling animal habitat, (vii) harboring biodiversity, and (viii) buffering against toxic accumulation of trace metals and xenobiotic compounds. This review focused on soil health responses to forage and grazing land management in the humid region of the eastern United States. Areas for further research were also identified.