Soil properties change during the transition to integrated and organic apple production in a New York orchard

We investigated soil quality in a 'Liberty' apple (Malus x domestica Borkh.) orchard on 'M.9' rootstocks, during and after transition from conventional to integrated (IFP) and organic (OFP) fruit production systems. Chemical composition, physical properties, and biological properties were measured at 0-6 and 6-12 cm soil depths over four years. Weed coverage and biomass were also measured. Terminal-restriction fragment length polymorphism analyses determined soil bacterial and fungal community compositions. Mulch with infrequent herbicide application provided effective weed control in IFP, and increased soil organic matter. pH. nutrient availability, microbial biomass C, and microbial respiration. Mechanical cultivation and chicken manure compost were used for OFP, which increased soil porosity. decreased aggregate stability, and increased potentially mineralizable and total inorganic N. Under OFP, cultivation suppressed weeds for 2-4 week intervals, but overall weed coverage was greater than under IFP. For most measurements, minimal treatment differences were found at 6-12 cm soil depth. Sampling time influenced bacterial communities more than the treatments but by the final sampling dates, fungal communities in the 0-6 cm depth segregated by treatment. Soil quality did not improve as much in OFP as in the IFP system soil. (C) 2011 Elsevier B.V. All rights reserved.