Monday, November 13, 2006 - 2:15 PM

Using Phosphorus and Strip-kill to Increase Tall Fescue Seed Production in Pastures.

Will Mcclain, "University of Missouri, Columbia", 1-31 Ag Bldg, 1-31 Ag Bldg, Columbia, MO 65211, United States of America and Dale Blevins, "Agronomy Dep., 1-87 Agric.Bldg", University of Missouri, University of Missouri, Columbia, MO 65211, United States of America.

Missouri is one of the leading states in the nation for tall fescue (Festuca arundinacea) seed production. Unlike Oregon, where tall fescue is managed for seed yields which average ~1,500 lbs/acre, Missouri seed is harvested from pastures which are managed for beef production, and yields typically range from 100 – 600 lbs/acre. Classic literature mentions mature stands of tall fescue becoming “root-bound” and producers often utilized shallow plowing to rejuvenate the stand to improve seed yields. However, Missouri pastures can be quite steep, and plowing can increase the risk of erosion. Killing strips of tall fescue in pastures with herbicides has been used for improving summer forage production. The strip-kill process provides a method to revitalize the root system of tall fescue pastures without disturbing the soil.

The objective of this study is to determine if tall fescue seed production could be increased with late summer phosphorus (P) fertilization in a strip-kill management system. Strips of tall fescue were killed with Roundup® leaving rows of live tall fescue and P fertilization rates of 0, 25, 50, 100, and 200 lbs of P/acre were applied. Together, strip-kill and P fertilization increased seed yields from 200 to 300% compared to control plots in the first year. In the second year of the study, treatments were not reapplied to determine the residual effects of strip-kill and P fertilization. Yields were increased from 50 to 200% compared to untreated controls for the second year’s harvest. Strip-kill has the potential to provide Missouri tall fescue seed producers with a management tool that improves seed yields with little increased risk of erosion.