Soil–Nutrient Interactions and Drivers of Nutrient Availability in Semi-Arid Pomegranate Orchards of Western Maharashtra, India

Abstract

Background: Pomegranate (Punica granatum L.) is an important fruit crop in India, and Maharashtra’s Solapur district is a leading production region. Proper soil fertility management is essential for maintaining yield, quality, and resilience to environmental challenges. Aims: The present study aimed to assess variability in soil chemical properties and to examine interrelationships among major nutrients, secondary nutrients, and micronutrients in pomegranate-growing soils of Solapur district, Maharashtra, India, to support site-specific nutrient management strategies. Study Design: A field survey-based analytical study was conducted using descriptive statistical analysis and correlation analysis to evaluate soil fertility variability and nutrient interactions. Place and Duration of Study: The study was conducted in the major pomegranate-growing tahsils of Solapur district, Maharashtra, namely Madha, Pandharpur, Sangola, Malshiras, and Mohol. Surface soil samples were collected from representative orchards during the cropping season. Methodology: A total of 150 surface soil samples (0–15 cm depth) were collected from pomegranate orchards across the selected five tahsils. Soil samples were analysed for pH, electrical conductivity (EC), organic carbon (OC), macronutrients (N, P, K, and S), secondary nutrients (Ca, Mg, and Na), and micronutrients (Cu, Fe, Mn, Zn, and B) using standard laboratory procedures. Descriptive statistics, including mean, range, standard deviation, and coefficient of variation (CV), were calculated. Pearson’s correlation analysis was performed to determine relationships among soil properties and nutrients. Results: The soils were slightly alkaline, with a mean pH of 8.09 and low variability (CV = 4.12%). Electrical conductivity exhibited high variability (CV = 50.20%), indicating differences in soil salinity across locations. Organic carbon showed a moderate positive correlation with nitrogen (r = 0.39). Available nitrogen varied from 97.80 to 338.45 kg ha⁻¹ (CV = 26.81%), while phosphorus ranged from 7.64 to 30.87 kg ha⁻¹ (CV = 27.07%) and potassium ranged from 162.28 to 660.20 kg ha⁻¹ (CV = 36.26%), occurring predominantly in medium to high fertility classes. Sulphur was high in 87% of samples, ranging from 12.04 to 67.20 mg kg⁻¹ (CV = 39.40%). Iron showed substantial variability (CV = 55.62%). Correlation analysis indicated a moderate positive association between OC and N (r = 0.39), whereas negative correlations involving EC may indicate that increasing salinity affects the availability or mobility of certain nutrients. Conclusion: The study demonstrated considerable spatial variability in soil fertility parameters across pomegranate-growing regions of Solapur district. Organic carbon had an important role in nutrient availability, while localised salinity variation influenced nutrient distribution. The findings emphasise the need for site-specific nutrient management practices to improve soil health, nutrient use efficiency, and sustainable pomegranate production.