Temperate fruit farming in fragile lands of the Northwestern Himalayan region: Implications for subsoil nutrient availability, nutrient stock and soil quality

In recent years, soil fertility in the Northwestern Himalayan (NWH) region has deteriorated partly due to accelerated soil erosion but mainly due to ineffective nutrient management for field crops. However, it is largely unknown whether long-term temperate fruit farming has adverse effects on the soil fertility in NWH or not. Therefore, we conducted a study with the purpose of evaluating the impact of different land uses in the NWH ecosystem, namely: peach orchard (PO), apple orchard (AO), fertile-fallow land (FL), and barren land (BL) on soil physico-chemical characters, nutrient storage capacity, and soil quality index (SQI), along a soil-depth gradient. A total of 116 composite soil samples [four treatments (i.e., land uses), 4- soil depths (0-0.2, 0.2-0.4, 0.4-0.6, and 0.6-0.8 m) and 5, 9, 9, and 6 replications for PO, AO, FL, and BL systems, respectively] were collected for laboratory analyses. Across depths, the soils under temperate fruit plantations had better soil physical conditions (i.e., lower bulk density and higher porosity) over FL and BL lands. The soils in this study can be categorized as slightly acidic to near neutral in soil reaction. Soils under temperate fruit plantations (PO and AO), averaged over depths, had significantly (p < 0.05) less quantity of soil organic C, available nutrients (i.e., primary-, secondary-, and micro-nutrients), nutrient storage capacity, and indices of soil quality, as compared to FL lands. These unfavourable effects were augmented in subsoils (0.2-0.8 m) than topsoils (0.0-0.2 m) affecting secondary- and micro-nutrients more than primary-nutrients. Results further revealed that these lands display a less favourable (i.e., very high) C:N ratio that could easily be degraded if brought under intensive farming. Restoration of depleted soil fertility in temperate fruit-tree-based ecosystems of NWH could be achieved through incentive-based building-up of soil organic matter and adoption of a soil-test-based nutrient management regime.

Automated summary

The study demonstrates that soil fertility in temperate fruit plantations in the Northwestern Himalayan region is lower compared to fallow fertile lands, with poorer soil physico-chemical characteristics and nutrient storage capacity. Soil organic carbon and various nutrients are less in temperate fruit plantations than in fallow lands.