Combined effect of land use change, long-term soil management and orchard age on variability of soil quality of fruit orchards under monsoon climate

Abstract

The combined effect of land use change, long-term soil management, and orchard age (18–40 years) on soil quality of guava (Psidium guajava L. cv. Allahabad Safeda) and sapota (Manilkara achras Mill. cv. Cricket Ball) orchards was investigated. Besides, the soil quality of the orchards was compared against an adjacent forest soil (AFS, considered a baseline ecosystem). Values of pH, SOC, porosity, PHA, DHA, GSA, ExCa, ExMg, and DTPA-Cu were significantly lower in drip circle soils relative to inter-row space soils. The extent of reduction was prominent in older orchards. There was a significant building up of BD, AvP, AvK, DTPA-Fe, and DTPA-Zn in drip circle soils relative to inter-row space soils. The soil variability between drip circles and inter-row spaces across the soil depths was significant (p < 0.01). Principal component analysis (PCA) plots were generated to determine the variability of soil quality among orchards and AFS. Long-term soil management (18–40 years) induced soil spatial variability within the orchards. Analysis of similarity showed a significant difference in variability of soil quality within an orchard, among the orchard types, and between the orchards and the AFS. Except for soil AvK, all soil quality attributes maintained a significant correlation with the PC-axis-1 (p < 0.05 and 0.01) that explained maximum variability (40.2%–49.4%). The DHA and SOC contributed the maximum variability (r = 0.95 and 0.92, respectively with PC axis-1). In conclusion, the stronger factor of the variability of soil quality was in the order of land use change > soil management > orchard age.