Economic and environmental benefits of integrated paddy-cum-fish farming in the smallholder systems of Meghalaya, North-east India

Abstract

The efficiency and sustainability of paddy-fish integrated farming were studied under the hill agro-climatic conditions of Meghalaya, North-east India. A five-year study (2018-19 to 2022-23) was conducted in four blocks of Ri-Bhoi District, with 20 replicate plots of 0.1 ha each per block, covering a total study area of 8 ha. Traditional paddy monoculture was compared with an integrated system combining the improved rice variety RCM-10 with a composite culture of Amur carp (40%), Mrigal (30%), and Silver barb (30%) at a stocking density of 0.5 fish m^-² (5,000 fingerlings per ha). Fish growth was assessed monthly (n=30 per species per plot), and soil and water quality were monitored quarterly and weekly, respectively. The integrated system earned higher net returns than monoculture (`108,555 vs 44,220 ha^-1), but its benefit-cost ratio (BCR) was lower (1.61 vs 2.18) because fish seed and feed raised the cost of cultivation considerably. Mean fish production was 1,050 kg ha^-1, with a stocking-weighted survival of 73.7%. Rice yield under integration (3,465 kg ha^-1) was 23% lower than in monoculture (4,500 kg ha^-1), partly because the peripheral trench and sump reduced the cropped area by about 13%. Soil organic carbon increased by 23%, pest incidence decreased by 65%, and irrigation water productivity improved by 30%. The system has potential for upscaling in Meghalaya, provided farmers can meet the higher working capital requirements and the associated yield and labour trade-offs are addressed through appropriate extension support.

Keywords: Benefit-cost ratio, Paddy-fish culture, Resource use efficiency, Smallholder farming, Sustainable agriculture