Effects of Soil Balancing Treatments on Soils, Crops and Pests in Organically Managed Farms.

Organic farmers in the Midwest use a wide variety of soil amendments as a practice to “balance” the soil. Farmers trust that balancing soils improves soil quality, producing better crops and reducing weed pressure. William Albrecht in the 1970’s concluded that if the soil saturation of the major exchangeable cations are between 65-85% for Ca, 6-12% for Mg and 2-5% for K, plant nutrition will be balanced. More recently, balancing includes amendments thought to enhance soil biology, increasing soil’s capacity to store and release minerals. Combined mineral amendments and organic/bio-active soil products can be expensive and while farmers believe they are benefiting from these expenditures, there is no objective evidence to confirm their belief. We conducted on-farm studies at six locations in Northeast Ohio, with the overall goal of determining the effect of gypsum, with or without organic/bio-active products, on the soil microbial community, crop quality, weed populations, and soil chemical and physical characteristics. The experimental design was a randomized complete block with 4 replications. Each farm had its own Fertility Program (FP) and treatments were FP only, FP+gypsum, FP+organic/bio-active products (kelp, molasses, humates, compost, liquid fish, seaweed, microbial inoculants), and FP+gypsum+organic/bio-active products. Soil health and biological properties were measured, including soil respiration, active carbon, protein content, microbial biomass, enzymatic activity and a complete mineral analysis. In addition, the weed seedbank and in-field weed pressure were evaluated during the growing season. Crop foliar samples were taken at mid-season for nutrient analysis, and fruit quality was determined after harvest. Results from 2016 showed no significant differences among treatments regarding soil mineral analysis. However, differences were found with crop quality and soil health/biology measurements. This study is being repeated for a second year using the same plots, and impacts on soil and crop quality and weeds will be further evaluated.