Optimizing turmeric productivity: Integrating intercropping systems, fertilizer regimes, and normalized difference vegetation index-based remote sensing for precision agriculture

Intercropping and optimized nutrient management are critical strategies for enhancing crop productivity and resource use efficiency in tropical agroecosystems; however, their integrated effects on turmeric ( Curcuma longa L.) under precision agriculture frameworks remain insufficiently explored. This study evaluated the performance of turmeric under different intercropping systems, assessed the influence of graded fertilizer levels using Normalized Difference Vegetation Index (NDVI) as a proxy for crop vigor, and identified optimal intercropping–fertilizer combinations for maximizing productivity. A two-year field experiment (Kharif 2020–21 and 2021–22) was conducted using a split-plot design comprising four intercropping systems and three fertilizer levels (100%, 125%, and 150% RDF). Sole turmeric recorded the highest NDVI values (0.90, 0.74, 0.46 in 2020–21 and 0.86, 0.71, 0.44 in 2021–22 at 90, 150, and 210 DAS, respectively) and maximum dry rhizome yield (7.56 t ha⁻¹ pooled). However, the turmeric + sweet corn (2:1) system exhibited superior system productivity, achieving the highest turmeric equivalent yield (9.20 t ha⁻¹ pooled) and land use efficiency (LER: 1.48 and 1.41). Increasing fertilizer levels significantly enhanced NDVI and yield, with 150% RDF producing the highest NDVI (0.87–0.47) and dry rhizome yield (6.68 t ha⁻¹ pooled). The study demonstrates that NDVI effectively captures treatment-induced variations in crop vigor and resource use efficiency. Integration of NDVI-based monitoring with optimized intercropping and nutrient management provides a robust framework for precision agriculture, enabling improved productivity and sustainable turmeric cultivation.