Effects of organic amendments on soil biota on a degraded rangeland

Wheat straw, bark and wood chips, and dried municipal sludge were placed on native range plots in N-central New Mexico. Organic amendments had little or no effects on decomposition of straw, litter respiration, soil respiration, biomass of soil microflora, and populations of most of the soil biota in the second year of the study. There may be long-term benefits from application of recalcitrant mulches like wood chips and bark, but the less recalcitrant mulching materials like straw and low application rates of sludge produce no measurable benefit. -from Authors