Ecosystem-level Impacts of Chickpea Intercropping and Nutrient Management on Phenology, Land Equivalent Ratio and Microbial Populations

A two-year field investigation (2023–2024) was conducted at the Agronomy Research Farm, G.D. Goenka University, Haryana, to evaluate the effects of integrated and sole organic nutrient management on the phenology, productivity, and land-use efficiency of chickpea (Cicer arietinum L.) under different intercropping systems. The experiment was laid out in a split-plot design comprising three nutrient management regimes—sole inorganic (NM₀₀), integrated (50% RDF + 50% vermicompost; NM₀₁), and sole organic (NM₀₂)—and four intercropping combinations: sole chickpea (IC₀₀), chickpea + oats (IC₀₁), chickpea + mustard (IC₀₂), and chickpea + barley (IC₀₃). Results indicated that mustard-based intercropping (IC₀₂) significantly advanced flowering, whereas oats intercropping (IC₀₁) delayed phenological development due to competitive stress. Integrated nutrient management (NM₀₁) enhanced early flowering and improved overall crop performance through balanced nutrient availability and improved soil microbial activity. The highest chickpea equivalent yield (CEY) was recorded in sole chickpea (21.46 q ha⁻¹), followed by IC₀₂ (19.16 q ha⁻¹), while IC₀₃ recorded the lowest yield (9.42 q ha⁻¹). Among nutrient regimes, NM₀₁ achieved the highest CEY (17.64 q ha⁻¹), confirming the synergistic advantage of combining organic and inorganic sources. Land equivalent ratio (LER) was highest under sole chickpea (1.00), with IC₀₂ outperforming cereal-based intercrops. Although nutrient effects on LER were statistically non-significant, the NM₀₁ × IC₀₂ interaction recorded optimal resource utilization. The study concludes that integrating mustard intercropping with balanced nutrient management enhances phenological efficiency, yield stability, and land-use optimization and soil microbial load. These results highlight the potential of integrated organic–inorganic nutrient strategies in developing climate-resilient, resource-efficient, and sustainable chickpea-based cropping systems suitable for semi-arid regions.