Management of Warm‐Season Annual Grass Residue on Annual Ryegrass Establishment and Production

Abstract

Early‐season forage production of annual ryegrass (Lolium multiflorum Lam.) is reduced in the southeastern USA when established no‐till rather than with conventional tillage. We hypothesized that annual warm‐season grass residue interferes with seedling establishment under no‐till. In a two‐year study, we evaluated six strategies for managing residue from warm‐season annual grass on annual ryegrass establishment, forage production, and soil moisture. Treatments were (i) no herbicide, mow, and leave residue; (ii) tillage 30 and 7 d before planting; (iii) apply glyphosate [isopropylamine salt of N‐(phosphonomethyl)glycine] 30 d before planting, mow, and leave residue; (iv) apply glyphosate 7 d before planting, mow, and leave residue; (v) apply glyphosate 7 d before planting, apply additional residue from twice the plot area (i.e., three times the other residue treatments); and (vi) apply glyphosate 7 d before planting, burn residue 1 d before planting. Better stands and more forage production at first harvest of annual ryegrass were obtained by spraying and burning residue (two‐year average of 96% stand and 0.92 Mg ha−1 yield at the first harvest) or spraying 30 d before planting (92% stand, 0.92 Mg ha−1) than when annual ryegrass was planted into a 3× residue (55% stand, 0.24 Mg ha−1). Soil moisture at planting did not cause differences in stand establishment among treatments. We conclude that managing residue during no‐till establishment by controlling warm‐season annual grasses and burning or controlling warm‐season annual grasses 30 d before planting can improve stands and forage production of annual ryegrass.