Research at the University of Minnesota found that warm-season grasses grown as annuals could improve the quality of horse pasture in northern climates, reports the American Society of Agronomy. Perennial cool-season annuals dominate northern pastures, where they easily survive winters and produce well in spring and fall, but these species experience a summer growth slump that reduces forage quantity and quality. Researchers tested warm-season forages including teff, sudangrass, sorghum sudangrass, and both Japanese and Siberian millet, grown as annuals. All of the grasses were found to supply adequate nutrition for horses, with sudangrass and sorghum-sudangrass showing the greatest yields. However, most of the forages had high nitrates, leading researchers to warn that nitrate levels should be closely monitored in these forages. They suggest that northern growers may want to plant an area with warm-season grasses managed as annuals for summer grazing.