Soil Physico-chemical Responses to Integrated Nutrient Management in Lentil Intercropped with Bhimal (Grewia optiva) in Agroforestry vs. Open Systems

The growing concern over health risks associated with the heavy use of chemical fertilizers and pesticides in India, which have been linked to rising cancer cases, underscores the need for sustainable agricultural practices. Integrated Nutrient Management offers a promising solution to enhance soil fertility and support crop health, especially for lentil cultivation within agroforestry systems. This study, conducted at Dr. Y. S. Parmar University of Horticulture and Forestry in Nauni, Solan, Himachal Pradesh, examined the effects of INM on the soil’s physical and chemical properties when lentils were intercropped within a Grewia optiva (Bhimal) agroforestry system in the mid-hills region of Himachal Pradesh. The experiment evaluated various combinations of organic and inorganic fertilizers, including T1: Recommended Dose of Fertilizer, T2: Farmyard Manure, T3: Vermicompost, T4: Goat Manure, T5: 50% Recommended dose of fertilizer + 50% Farm yard manure, T6: 50% Recommended dose of fertilizer + 50% Vermicompost, T7: 50% Recommended dose of fertilizer + 50% Goat Manure, and T8: Control. These treatments were applied in plots both under the Bhimal-based agroforestry system (S1) and in open field conditions (S2), with three replications per treatment following a factorial randomized block design. Key physical parameters such as bulk density, particle density, porosity, and soil moisture were measured alongside chemical properties, including soil pH, electrical conductivity, organic carbon content, and the availability of nitrogen, phosphorus, and potassium. Data collected over two years was analyzed using R Statistical Software, revealing that INM significantly improved soil properties in the agroforestry system compared to the control. Notably, 100% FYM emerged as the most effective treatment, enhancing soil porosity, moisture, pH, and nutrient availability (N, P, and K). Improvements in soil structure and nutrient levels were particularly evident in the second year, positively impacting lentil growth and yield. The study highlights the potential of INM to promote sustainable, chemical-free agriculture in hilly areas, offering valuable recommendations for farmers and policymakers focused on sustainable agriculture. Specifically, 100% FYM is recommended for improving soil health and crop productivity in the mid-hill region of Himachal Pradesh, providing a model for similar agro-ecological zones aiming to reduce chemical inputs and support human health.