Abstract

The present study was conducted under 3 developed agroforestry systems that is, Khasi mandarin (Citrus reticulata), Alder (Alnus nepalensis) and Khasi pine (Pinus kesiya) in the state of Meghalaya, northeast India to study the litter dynamics and physico-chemical properties of soil. The findings of our investigation revealed that the soil texture in 3 systems varied from sandy to loamy sand and water holding capacity varied significantly (P < 0.05) between plots and depths. Porosity and soil temperature was higher at surface layer than into the subsurface layer. Soil was acidic in all the plots. Soil organic carbon as well as organic matter content was high in Khasi mandarin-based system than the other systems. Total Kjeldahl nitrogen concentration was low in all the soils. It was lowest in Khasi pine based system and a similar trend was observed in concentrations of available phosphorus and potassium. Monthly variation in litter mass varied markedly between different agroforestry systems. The leaf litter constituted 65 - 76% of total litter mass. The rate of weight loss of Alder leaf litter was much faster than other 2 species. Litter decomposition was fast during rainy season and slow during winter season. Rate of release of nitrogen and phosphorus from the decaying leaf litter of Alder occurred at much faster rate compared to Khasi mandarin and Khasi pine, however, potassium release was faster from Khasi mandarin. Total input of N, P and K through litter was higher in Khasi than other 2 species due to greater litter production.

Key words: Agroforestry systems, litter accumulation, nutrient release, soil properties, northeast India.