Long-Term Integrated Nutrient Management Improves Carbon Stock and Fruit Yield in a Subtropical Mango (Mangifera indica L.) Orchard

Perennial trees especially fruit trees are considered to be the most competent biological system where atmospheric carbon dioxide is transformed into long-lived soil carbon despite their nutritional and export value. Higher carbon stock helps to sustain production and soil ecosystem services. Better crop nutrition promotes carbon stock. Feasibility of integrated nutrient management in carbon sequestration needs to be evaluated under a subtropical humid condition. An experiment was carried out in randomized block design to study the feasibility of integrated nutrient management for improving soil properties, nutrient availability, fruit yield, and carbon stock in a mango (Mangifera indica L.) (cv. Langra) orchard under a subtropical condition. Various combinations of integrated (farmyard manure, vermicompost, straw mulch, biofertilizers) nutrient management practices were evaluated in two consecutive years in a 30-year-old mango orchard. The results revealed that the organic mulching with straw and conjoint application of farmyard manure and vermicompost improve nutrient availability, microbial activeness (29-44%), and carbon stock (40%) in soil at 0-60 cm soil depth which ultimately improves fruit yield (26-34%). Hence, adoption of integrated nutrient management practices through the application of farmyard manure, vermicompost, and organic mulching with straw would uphold the fruit yield and carbon stock in soil and also promote CO2 sequestration in soil and less greenhouse gas emission, which paved viable economic options to mitigate climate change.