Effect of indigenous land - use systems on nutrient availability in hilly terrain Alfisols of Meghalaya

Abstract

An experiment was conducted during pre- and post-monsoon seasons of 1990 to study the effect of field crops, tree crops and dairy-based land-use systems on soil-fertility status in Ri-Bhoi and Ri-War areas of Meghalaya. The exchangeable Ca²⁺ +, AI³⁺, K⁺, Bray's P₂₊-P, fulvic and humic carhon conlents in the top soil (0 20 cm depth) were greatly influenced by these systems but the magnitude differed from one land use to  another. The lowest organic carbon and the maximum AI³⁺ contents were found in cereal-based land use, whereas the maximum accumulation of organic carbon in conjunction with complete disappearancce of AI³⁺ was observed under dairy farming within 15 years of adoption, Apparently, AI³⁺ content greatly increased in subsoil due to less quantity of organic carbon and excnangeable Ca level, A positive and highly significant correlation was detected between organic carbon and Ca²⁺ (r = 0.74**), humic carbon (r= 0.75**) fulvic carbon (r = 0.74**) and Bray's P₂₊-P (r = 0.85**). The soil pH showed a positive association with Ca²⁺(r= 0.73**) but an inverse relationship with AI³⁺ (r = 0.91**). The overall sustainability in restoration and maintenance of soil ferlity followed the trend: dairy farming> tree-based land use> cereal-based cropping. Thus dairy- and tree-based land Uses showed self-sustainable systems for soil productivity through effective recycling mechanism, as these are well maintained in complete absence of chemical fertilizers and amcliorative on sloping-land conditions.