Benefits Of Diversity In Perennial Pastures For Soil Health And Forage Production

A study performed by the USDA Pasture Lab in State College on a Hagerstown silt loam soil compared a two-way mix of ‘Tekapo’ orchardgrass/ ‘Will’ white clover with a five-way mix of ‘Puna’ chicory/’Tekapo’ orchardgrass/’Bronson’ tall fescue/’Will’ white clover/’Amerigraze’ alfalfa.

The forages were seeded in a field that had been in alfalfa. The alfalfa was killed in October 2003, seeded to rye in November, and disked and planted to oat in April. This was terminated in July and forage mixes were no-till planted. Besides lime, 10 lbs/A N, 50 lbs/A P2O5, and 210 lbs/A K2O in 2004 no further fertilization occurred.

Paddocks were grazed by beef cattle when their average height was 10 inches, to 4 inches height, usually 5 times per year. Dry matter grazing yield (what the animals consumed) is shown in the following figure (to convert kg/ha to lbs/A multiply by 0.9).

DiversityYearly Forage Yield of a Five and Two Species Pasture Mix

Key lessons learned from this study:

The 5-species mix produced 31% more forage than the 2-species mix over the 9 years of this trial.

The diverse mix produced more in wet and dry years, but the difference was greater in wet years.

Diverse mixture was typically 2 inches taller when grazed

Post-grazing forage density was 35% greater in the diverse mix

At the end of 8 yrs, the diverse mix was dominated by tall fescue (50%) and orchard grass and white clover (each 20%). The rest was weeds (esp. Kentucky bluegrass).