How should I go about preparing soil for organic fruit plantings?
Answer: Important considerations in preparing a site for an organic orchard include alleviating soil compaction, enhancing fertility, adjusting soil pH, and managing weeds, pests, and diseases. Attention to the details of site preparation can help reduce weed and disease problems and assure a vital planting through soil improvement. What needs to be done depends on the previous use of the land, including crops grown, current vegetation, and the presence of pests and diseases. Many growers rip or chisel the soil to loosen layers of compaction before they plant a new orchard or vineyard because deep tillage will be disruptive once the trees are established. Before establishing an orchard or vineyard, it is important to adjust the soil pH to best suit the crop you’ve selected. Soil tests can assess current soil conditions, including pH, mineral levels, and their relative proportions. Traditionally, pH has been adjusted through applications of lime (to raise the pH) or sulfur (to lower pH). Most fruit plants perform best around pH 6.5, although they tolerate a pH range between 5.5 and 7.2. Blueberries are an exception. They require an acid soil?ideally pH 4.8 to 5.2. Soil test results help guide applications of soil amendments, such as compost, lime, gypsum, or other rock powders, to provide good soil conditions that meet the nutritional needs of the orchard. In general, fruit crops do not require highly fertile soils for good production, though this varies with the species. Highly fertile soils, rich in nitrogen, can promote too much vegetative growth at the expense of fruiting in trees such as apples. A nutritionally balanced soil, proper soil pH, and plentiful organic matter are the fundamentals of an organic fertility-management plan for fruits. Pre-plant soil improvement for organic fruit plantings usually involves some combination of cover cropping and applications of compost, natural minerals, or other organic fertilizers.The ATTRA publication Soils and Sites for Organic Orchards and Vineyards provides much more information on this topic. It discusses site selection and soil preparation for fruit plantings. It also describes cover crop and mulching options for orchards and vineyard floors, and discusses fertilization and the role of mycorrhizae in maintaining healthy fruit plants.