Traditional agroforestry systems, one of the time tested and dominant land use from tropical to sub-tropical regions, were recognized for their contributions to food production, biodiversity conservation, and atmospheric carbon sequestration. Their management often varies from region to region. However, these systems frequently mimic economically managed land uses due to increased pressure on the monetary requirement of their managers. The present study aims to evaluate (i) tree density, (ii) tree diversity indices, and (iii) identify the biomass carbon important tree species managed by different communities of the Indian Eastern Himalayan region. We found that the Mizo community harbored the highest number of tree species (35) in the traditional agroforestry system with the highest tree diversity index (3.47). Total biomass carbon of tropical agroforestry systems managed by different communities ranged between 4.72 Mg ha⁻¹ (Meitei) and 29.26 Mg ha⁻¹ (Bengali). Similarly, in the sub-tropical traditional agroforestry system, the highest and the lowest biomass carbon was observed in Mizo- (10.93 Mg ha⁻¹) and Angami- (6.05 Mg ha⁻¹) managed systems. Of the 31 biomass carbon, important species found across the traditional agroforestry systems, Artocarpus heterophyllus, had the highest occurrence (50%), followed by Parkia timoriana (37.5) and Amoora rohituka, Delonix regia, Mangifera indica, and Toona ciliata (25% for each species). Farmers’ preference to cash return of a species, trees density, and basal area were the determinant factors in the carbon stock potential of these systems. The present study suggests that the farmers’ preferred and dominant species in their agroecosystems have a limited scope of enhanced biomass carbon storage. Therefore, improvement of traditional agroforestry systems through selective incorporation of biomass carbon important tree species is recommended to enhance the carbon sink capacity of these systems.

The present study reports the potential of carbon (C) storage in traditional agroforestry systems (i.e., a set of age-old agroforestry systems) under waterlogged environmental conditions from north-eastern India. An experiment was conducted in a farmer’s field and further used CO₂FIX model, allometric equations, and destructive sampling methods to know the potential of C sequestration. In this study area, agroforestry system is dominated by woody perennials like Areca catechu, Cocos nucifera, Mangifera indica, Artocarpus heterophyllus, Melocanna baccifera, and Colocasia esculenta as annual crop component. Need-based management of the drainage system has been built-up by making broad/narrow bunds for maintaining water levels at different stages of plant growth. The total annual carbon storage potential of this traditional agroforestry system was estimated as 103.760±8.630 t ha⁻¹year⁻¹. The highest annual carbon storage potential (97.900±8.090 t ha⁻¹year⁻¹) was recorded in annual crop components (i.e., Colocasia) followed by trees and its underlaid soil (4.250±0.340 t ha⁻¹year⁻¹) and lowest for bamboos (1.610± 0. 200 t ha⁻¹ year⁻¹). However, the estimated carbon stored, annually, was 24.992±1.502 t ha⁻¹ year⁻¹ in which Colocasia share maximum contribution (19.600±1.080 t ha⁻¹ year⁻¹) followed by trees + soil (3.798±0.229 t ha⁻¹ year⁻¹) and the minimum contribution from bamboos (1.594±0.193 t ha⁻¹ year⁻¹). Moreover, total carbon loss from harvesting of this system was 78.768±7.128 t ha⁻¹ year⁻¹. The study, therefore, recommends this agroforestry system for other waterlogged ecosystems at regional and/or global scale under a warm per-humid climate for both livelihood opportunities and environmental sustainability.

The fruits and vegetable waste has become the highest compared with the production rate. These types of wastes had reached up to 70% by 2019–2020 as estimated by Food and Agriculture Organization (FAO). Improvisation of the performance of still using fibre insulation (Artocarpus heterophyllus rags and Azadirachta indica gum (AHRAIG)) has been carried out in this study. Potable water demand in arid areas is a vast problem where fresh water is very expensive. The proposed solar still (PSS) retains the basin temperature and raises the rate of evaporation. Rags are latex-like filament extracted from the waste of the jackfruit peels and an adhesive agent from Azadirachta indica tree. A comparison is made among still without insulation (SWI), still with polystyrene insulation (SPI) and still with fibre insulation (SFI) in producing the fresh water under same ambient conditions. The experiments result a promising yield of 9.3% rate of rise of potable water produced using AHRAIG insulation related to conventional still. The energy efficiency is premeditated as 26.45%, while the exergy efficiency is 4.07%. The production of the potable water reached 2.58 L/m² for still with polystyrene insulation, 3.26 L/m² for fibre insulation and 1.93 L/m² for still without insulation, respectively.