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 30year-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 CO 2 sequestration in soil and less greenhouse gas emission, which paved viable economic options to mitigate climate change.

The present investigation was carried out to study the effect of potassium and zinc on Sweet orange (Citrus sinensis Osbeck) cv. "Mosambi" during the year 2018. Eight years old uniformly grown Mosambi Sweet orange plants, grafted on Karna Khatta rootstock and planted at a distance of 3.0 x 2.5m were used in this investigation. The investigation was carried out in high density planting area of Bihar Agricultural College, Sabour, Bhagalpur, under the Department of Fruit & Fruit Technology. Twelve different treatments of K and Zn in a simple randomized block design were used. Various treatments showed significant effect on physiological, vegetative and yield parameters. The maximum leaf area (23.53cm 2 ), total chlorophyll content (3.04mg/g), leaf relative water content (75.82%), specific leaf weight (0.0164g/cm 2 ) were observed in T12 (K2O @500g +Zinc sulphate @200 g) whereas minimum in T1(control). The maximum increase in current season shoot length (13.22cm), canopy spread (64.17cm), trunk girth (1.93cm) and plant height (36.67cm) were also recorded in T12 (500g K2O and 200g ZnSO4) whereas minimum in control. The maximum number of fruits per tree was counted (92.67) in T8.