Carbon management in diverse land- use systems of eastern Himalayan subtropics

Abstract

The north eastern region (NER) of India has ~48% degraded land of its total geographical area of 26.23 m ha. Shifting cultivation, cultivation along the slope, poor soil conservation measures, extractive farming practices like excessive disturbance of soil in sloping lands, no or very low application of organic manure and fertilizer, residue burning, deforestation, etc., are the major causes of land degradation in the NER. Improving carbon (C) status of the soil and maintaining it at critical level (1.5% or more) through Good Agricultural Practices (GAP) in subtropical hill ecosystems offers an opportunity for sustainable agriculture and environmental security. Among the NER states, Tripura has highest area (>89%) under relatively low soil organic carbon (SOC) content (1.0-1.5%) followed by Assam (62.83%) and Meghalaya (19.9%). Whereas, SOC content in mid and high attitude areas of the NER ranges from 1 to 3.5% or more with trend of increasing SOC as altitude increases. In general, soils in the tropical and subtropical ecosystems of the NER have lower SOC than those of temperate and alpine ecosystems. Practising Integrated Farming System, conservation agriculture, location-specific agroforestry system, multiple cropping, crop intensification and diversification, rehabilitation of degraded lands through appropriate amelioration measures like liming, organic amendments, etc. have the potential to restore SOC content, improve agricultural productivity and will help in the advancement of food and nutritional security in the region.