Soil–plant Nutrient Dynamics under Nano Fertilizer Application in Apple Orchards of Kashmir Valley

Abstract

Effective nutrient management is essential for sustaining soil fertility and productivity in apple orchards of the Kashmir Valley. Under the project "Demonstration, Validation and Popularization of Nano-fertilizer for Sustainable Agriculture Development in Kashmir Valley," field demonstrations comparing different fertiliser regimes integrated with Nano Urea and Nano DAP (foliar spray @ 2 ml L⁻¹, two sprays) were conducted in Budgam, Pulwama and Anantnag districts during 2024–25. Soil and leaf samples were analysed for pH, electrical conductivity (EC), organic carbon (OC), available N, P and K, and leaf N, P and K. Treatments integrating nano-fertilisers, particularly T18 (Urea 122 g + DAP 136 g + MOP 250 g + Nano Urea + Nano DAP @ 2 ml at 25-day intervals), were superior to the 100% recommended fertiliser dose (T1) across all districts. In Budgam, pH declined from 7.09 to 6.39, EC rose from 0.13 to 0.20 dS m⁻¹, OC increased from 0.69% to 0.89%, and available N, P and K increased from 360 to 465, 19.0 to 27.2, and 225 to 335 kg ha⁻¹, respectively. Similar trends were observed in Pulwama and Anantnag, with available N increasing from 365 to 501 and from 378 to 530 kg ha⁻¹, respectively. Leaf nutrient status also improved markedly, with leaf N increasing from 1.86% to 2.37% in Budgam and from 1.95% to 2.46% in Anantnag. Treatment effects were statistically significant (P ≤ 0.05), with low coefficients of variation, indicating that integrating nano-fertilisers with reduced conventional fertiliser doses enhances nutrient availability, uptake and soil organic carbon while maintaining favourable pH and EC.