Title: Fact Sheet: Soil nutrient levels on grazing farms in the northeastern U.S. Authors
Submitted to: Extension Fact Sheets
Publication Type: Other
Publication Acceptance Date: March 2, 2009
Publication Date: March 3, 2009
Citation: Sanderson, M.A., Bryant, R.B. 2009. Fact Sheet: Soil nutrient levels on grazing farms in the northeastern U.S.. Northeast Pasture Consortium Fact Sheets. p. 1. Technical Abstract: Soil nutrient levels are one indicator of the level of nutrient management on farms. Pastures in the northeastern U.S. have often been classified as low in soil fertility. These reports focused mainly on grazing lands managed at a relatively low intensity. Our objective was to gain some insight into the level of various soil nutrients on grazing farms across the northeastern USA. We compiled soil nutrient information from three databases comprising a total of 215 pastures on 66 farms in nine states. The majority of pastures sampled had optimum to high levels of soil phosphorus (P) and potassium (K). Increased levels of soil test P have been associated with an increased risk of P loss in surface water runoff; however, other risk factors such as landscape position and hydrologic connections must be considered as well. Paddocks farthest from the barn tended to have lower soil P levels; however, there was a large range in soil P regardless of distance from the barn. High soil K may result in high forage K concentrations, which can cause metabolic problems in cattle. Nearly 60% of the pastures sampled had a low soil pH (between 5.1 and 6.4) indicating that liming may be beneficial on these pastures. Our research also showed that the use of single composite samples for soil test P is an appropriate indication of P concentration in runoff, because the compositing effect that masks “hot spots” during soil sampling also buffers against high concentrations of P being lost in runoff. Farms with more intensive grazing management have greater soil fertility levels and that these producers should be mindful of nutrient management practices.