91024
Alfalfa Response to Potassium Rate and Timing of Application.
See more from this Division: SubmissionsAlfalfa Response to Potassium Rate and Timing of Application.
See more from this Session: Graduate Student Oral Competiton – Soils
Monday, February 2, 2015: 1:30 PM
Westin Peachtree Plaza, Chastain F
Alfalfa is a high-quality forage crop grown by Tennessee farmers primarily as a feed source for horses and dairy cattle. While alfalfa can be a high-yielding forage crop, it requires attention and proper nutrient management to perform optimally. Potassium is an important nutrient to alfalfa growth, development, and maintenance of a strong stand. University of Tennessee (UT) recommendations for K fertilization of alfalfa are currently 213-269 kilograms K2O per hectare for medium to low testing soils, respectively. A three-year study was conducted in Springfield, Tennessee to refine UT recommendations for K in alfalfa. Alfalfa was established on a Staser loam (Cumulic Hapludoll), which tested low in soil K throughout the study. Phosphorus and boron were applied at UT recommended rates (134 kg P2O5/ha and 1.12 kg B/ha) each spring at green-up. K was applied at rates of 0, 67, 134, and 269 kg K2O/ha each year. Each rate was applied in full each spring at green-up, and rates other than zero were also split to study effect of application timing. The 67 kg K2O/ha split treatment received half of its K2O at green-up and half after the first harvest. The 134 and 269 kg K2O/ha split treatments broke the K2O requirement into four applications, at green-up and after each harvest. Alfalfa was harvested four times per year, at about 30 day intervals. Yield and tissue K content were measured. The results of this research will help refine UT recommendations to alfalfa growers across the state.
See more from this Division: SubmissionsSee more from this Session: Graduate Student Oral Competiton – Soils