Litter Mass, Deposition Rate, and Chemical Composition in Bahiagrass Pastures Managed at Different Intensities

Abstract

ABSTRACTPlant litter is an important pathway of nutrient return to the soil in grazed swards, but the effects of pasture management on litter mass and composition are not well understood. This research evaluated the effect of management intensity, defined in terms of N fertilization and stocking rate (SR), on litter mass, deposition rate, and chemical composition in continuously stocked ‘Pensacola’ bahiagrass (Paspalum notatum Flügge) pastures growing on Pomona and Smyrna sands. Treatments were three management intensities: Low (40 kg N ha−1 yr−1 and 1.3 animal units [AU, one AU = 500 kg live weight] ha−1 SR), Moderate (120 kg N ha−1 yr−1 and 2.7 AU ha−1 SR), and High (360 kg N ha−1 yr−1 and 4.0 AU ha−1 SR). Greater management intensity resulted in less litter mass on the pasture early in the growing season and more litter mass later in the season. Rate of litter deposition was generally greatest for High and ranged between 23 and 40 kg organic matter (OM) ha−1 d−1 compared with 13 to 30 kg OM ha−1 d−1 for Low and Moderate management intensities. Increasing management intensity from Low to High resulted in greater litter N (14.1 vs. 22.9 g kg−1) and P (0.8 vs. 1.3 g kg−1) concentrations and lesser C:N (∼40 vs. 22), C:P (649 vs. 433), and lignin:N (5.8 vs. 4.4) ratios. More intensive pasture management was associated with greater litter deposition rate and litter quality than less intensive management, suggesting a larger nutrient contribution from litter in intensively managed swards.