Mitigation of Fungicide-altered Soil Physicochemical Properties and Nutrient Dynamics through Organic Ameliorants in Temperate Apple Orchard Soil

Abstract

Repeated fungicide application in apple orchards may influence soil physicochemical properties and nutrient cycling. This study evaluated four organic amendments—vermicompost (VC), farmyard manure (FYM), spent mushroom compost (SMC), and Trichoderma-fortified compost (CFT)—alone and in combination with captan, propanib, flusilazole and difenoconazole during a 60-day laboratory incubation of temperate apple orchard soil collected from Shalimar, Kashmir, India. Twenty-five treatments were arranged in a completely randomised design with three replications. Soil pH, electrical conductivity (EC), organic carbon (OC), and available nitrogen (N), phosphorus (P) and potassium (K) were measured at 0, 30, 45 and 60 days after treatment. At 60 days, vermicompost recorded a pH of 6.11, OC of 1.238%, available N of 484.7 kg ha⁻¹, P of 31.0 kg ha⁻¹ and K of 177.8 kg ha⁻¹, compared with 6.85, 1.000%, 449.5 kg ha⁻¹, 24.6 kg ha⁻¹ and 146.7 kg ha⁻¹, respectively, in the control. The other organic amendments also increased OC and available macronutrients over the incubation period, whereas fungicide-only treatments generally showed smaller changes. Fungicide–amendment combinations generally maintained higher nutrient and OC values than the corresponding fungicide-only treatments. Among the amendments, vermicompost produced the most pronounced numerical response in the measured soil properties. These findings support further field evaluation of organic amendments as components of integrated soil-fertility and disease-management strategies in temperate apple orchards.