Effects of different organic apple production systems on seasonal variation of soil and foliar nutrient concentration

Ground cover management system (GCS) on mature apple trees had small effects for the leaf nutrient statuses and tree performances but more affected soil nutrient. Wood chip treatment increased organic matter (OM), [NO 3], [Mg], and [B] in soil compared to the shredded paper, mowing understory vegetation, or black fabric cloth treated plots. Shredded paper treatment increased soil pH in the orchard soil that was previously acidic, which prevented leaf [Mn] toxicity.;Overall, seasonal nutrient concentrations in leaves grown under some of the GCS in mature and young apple trees followed the nutrient concentration patterns in conventional apple orchards.;In the greenhouse study, leachate from grass clipping mulch provided as an alternative organic nutrient source for improving plant growth and nitrogen use efficiency as well as reducing nitrate leaching potential in the field if vegetation is controlled.;All variables were more affected by GCS rather than interaction effect or nutrient source effect in an established organic orchard. Green compost treatment increased soil pH, electrical conductivity, OM, and most soil macro nutrient concentrations. Green compost and wood chip treated trees showed competitive return on investment because the systems filled the allotted space as quickly as possible with a canopy that provided early and sustainable yield of fruits in year 3. However, green compost treatment plot had high soil nitrate leaching potential.