Straw harvesting, fertilization, and fertilizer type alter soil microbiological and physical properties in a loblolly pine plantation in the mid-south USA

Harvesting fallen needles (straw) in loblolly pine (Pinus taeda L.) plantations provides forest owners with a substantial source of income, but this practice and the type of fertilizer used to replenish nutrients removed with straw harvests may alter soil microbiological and physical properties. This study was conducted to explore the influence of annual straw harvesting, fertilization, and fertilizer source (inorganic vs. broiler poultry litter) in a loblolly pine plantation in the mid-south USA on: (1) soil microbial biomass C, (2) soil dehydrogenase activity, and (3) key soil physical properties (soil strength, bulk density, porosity, aeration, soil moisture content, organic matter, and available water holding capacity). All treatments that included straw harvesting increased bulk density and reduced soil porosity. Annual straw harvesting conducted with annual fertilization of inorganic nitrogen and phosphorus fertilization was associated with the most pronounced increases in soil strength and reductions in organic matter, available water holding capacity, microbial biomass C, and dehydrogenase activity.