Tree Growth and Soil Nutrient Dynamics under Mahogany (Swietenia macrophylla G. King) and Wheat (Triticum aestivum L.) based Agri-silvicultural System

The present study investigated the tree growth and soil nutrient dynamics under mahogany-based agri-silvicultural system in West Bengal. The objective was to access its role in promoting ecological functions and sustainable land use. The mahogany trees exhibited a robust and steady growth, with mean tree height increment of 8.6 m to 10.5 m, and DBH from 11.4 cm to 12.9 cm and a sustainable increase in volume (54.05%), highlighting the species' suitability to intercropping. Compared to open-field cultivation, the agroforestry system significantly improved soil health. While the open system showed a decline in key soil physico-chemical properties at both depths, the agroforestry system demonstrated a marked improvement in these parameters with organic carbon increasing from 0.76 to 0.80%, nitrogen from 176.61 to 179.76 kg ha-1, phosphorous from 11.12 to 11.34 kg ha-1 and potassium from 163.80 to 166.88 kg ha-1. A trend of soil acidification was observed in both systems, being more prominent in the agroforestry plots where pH reduced from 5.31 to 4.90. The findings indicate that a mahogany-based agri-silvicultural system provides a more sustainable soil management approach by enhancing organic matter and nutrient retention than conventional open-field cultivation.