A Study of Nutrient Return Speed in Sorghum-Sudangrass Varieties

University of Kentucky (UK) senior Brandon Dooley is studying whether sorghum-sudangrass with a brown midrib trait adds nutrients back to soil quicker than varieties without the trait. Sorghum-sudangrass is a warm-season annual grass Kentucky producers use for summer grazing and pasture renovation. When livestock graze the forage, they leave behind plant residues on top of the soil that must decompose. 

Previous studies have shown that sorghum-sudangrass containing the brown midrib trait has less lignin than other varieties. (Lignin is a complex organic polymer that, with cellulose, forms the chief constituent of wood.) As a result, microbes in livestock’s rumen digest the forage more completely, which enhances the animal’s performance. UK College of Agriculture Food and Environment forage researchers think the trait may also speed up leftover plant residue decomposition. 

Dooley interned with UK Extension forage specialist Chris Teutsch through the USDA’s Research and Extension Experiential Learning for Undergraduates summer internship program. This work was supported by USDA’s National Institute of Food and Agriculture. For more information, read this UK News article.