Context The spatial interactions between agricultural intensification and soil health in upland agroecosystems, like the Eastern Ghats of India, remain poorly understood, constraining the scope of targeted interventions. Aim This research aims to delineate agricultural intensification zones across elevation gradients and to compare soil health across these zones. Method A semi-structured questionnaire survey was conducted among 372 farmers, to record data on cropping intensity, agrochemical inputs, fallow period, irrigation, and mechanization practices. Composite soil samples (n = 378) were collected through a systematic grid (5 km × 5 km) sampling approach to ensure spatial representativeness. Physico-chemical analysis of these samples was conducted (23 parameters); subsequently, the Soil Health Index (SHI) was computed. Further, the Agricultural Intensification Index (AII) was computed considering five different variables. Key results Agricultural intensification has seemingly weakened soil health, with a spatial negative correlation between AII and SHI (r = −0.64, P 0.05). The AII values varied from 0.23 to 0.91, identifying Jeypore, Borigumma, Kundra, Kotpad, and Boipariguda as high-intensity hotspots (Getis-Ord Gi*, P 0.01). The SHI ranged between 0.31 (poor) and 0.86 (very good). The highly intensified areas were distinguished by low organic carbon (0.42–0.65%), lower nitrogen availability (145–182 kg/ha), and extreme phosphorus deficiency (1 mg/kg), while the low-intensity zones were represented by higher organic carbon (1.8%), well-balanced macro-nutrient proportion, and better water holding capacity (65%). The maximum overlap/common grids were found between Poor SHI and High AII (2283; 20.6%), and the minimum was between Very Good SHI and Very High AII (25; 0.2%). The spatial variability of the AII–SHI relationship was further validated through regression analysis (ordinary least squares R2 = 0.57; geographical weighted regression R2 = 0.74) with local deviations attributed to micro-environmental conditions and management interventions. Conclusion This bi-index approach is a first-of-its-kind attempt globally, and was experimented with, through this study, in India’s heterogeneous upland agro-ecosystems, where it was anticipated that socioeconomic heterogeneity and micro-environmental heterogeneity modulate the AII–SHI interactions. Implications The study findings highlight unregulated intensification in vulnerable uplands, thereby accelerating soil health decline and providing a spatial framework to guide sustainable intensification approaches.
Prusty et al. (Tue,) studied this question.