Nitrogen accumulation of six groups of sorghum grown on a municipal biosolids use site

Groundwater contamination with nitrate (NO 3 − ) is a current problem in the U.S. Sources of contamination include disposal of municipal biosolids. Because sorghum ( Sorghum bicolor [L.] Moench) is an efficient scavenger of nitrogen (N) from the soil, its production on soils that receive biosolids may reduce N accumulation in those soils. An experiment was conducted to determine the amount of N accumulated by six types of sorghum. Three hybrids each of six types of sorghum (tropical, forage, sudangrass, sorghum × sudangrass, grain, and sweet) were evaluated for N accumulation on a municipal biosolids disposal site. Tropical sorghum and sorghum × sudangrass had the highest dry matter production and accumulated the most N. Nitrogen accumulation was largely a function of dry matter yield. Biomass produced was only adequate for beef maintenance diets but may be a useful biomass source for ethanol production from celulose.