Spatial variability and multivariate assessment of soil properties and nutrient availability in mango-supporting...

The comprehension of soil fertility in mango-supporting ecosystems and factors affecting it is very important, as it significantly influences the production of mango. In this study, soil characteristics were examined across ninety samples collected from eighteen orchards located at the Mango Research Sub-Centre in Rameshwar, Maharashtra. Spatial patterns and nutrient variability were analysed using GPS-based sampling, geostatistical tools, and principal component analysis (PCA). The data indicated that the silt loam soils (20.43-31.38% clay) have extremely acid (pH 4.36) to moderately acid (pH 5.99). In general, the soil samples had very high organic carbon (12.90-33.50 g kg^-1), available nitrogen (191.30-435.90 kg ha^-1), and potassium (145.49-766.53 kg ha^-1), which generally fell within low to medium categories, while phosphorus (21.80-80.79 kg ha^-1) tended to be moderate to high. Exchangeable magnesium (0.50-5.60 cmol⁺ kg^-1) and calcium (1.20-11.10 cmol⁺ kg^-1) were low owing to severe leaching. Among the micronutrient cations, iron, manganese, and copper were above their respective critical limits, whereas zinc (0.21-5.77 mg kg^-1) varied widely (deficient to adequate) across different locations. Variation among soil samples was noticeable for potassium and, to a lesser degree, nitrogen. PCA identified five major components that together accounted for nearly three-quarters of the total variability, with the first two components explaining over 74.9% of total variation. Overall, the non-saline soils of this region had sufficient quantities of available nitrogen, phosphorus, potassium, iron, copper, and zinc, barring small patches for nitrogen and zinc. These results emphasize the heterogeneous distribution of soil nutrients within mango orchards and warrant site-specific nutrient management approaches, which will undoubtedly assist in tailored nutrient regulation for higher productivity of mango in this eco-region.