Singh, VeerMelkani, Suraj2021-01-252021-01-252020-11https://krishikosh.egranth.ac.in/handle/1/5810160589A field study was carried out during 2019-2020 at Agroforestry Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar, to study the influence of different agroforestry tree species on soil properties and their potential for carbon sequestration in tarai region. The experiment comprised of nine agroforestry tree species viz., Anthocephalus cadamb, Pterospermum acerifolium, Delonix regia, Terminalia chebula, Chukrasia tabularis, Dillenia indica, Bambusa vulgaris, Lagerstroemia indica and Pithecellobium dulce along with a control in randomize block design with three replications. Soil samples were collected prior to the commencement of the monsoon season at 0-15 and 15-30 cm depth. All soil properties were significantly affected by the tree plantations and except bulk density, pH and electrical conductivity of soil all other parameters decreased at 15-30 cm depth of soil compared to 0-15 cm. There was slight decrease in the pH of soil under tree covers, whereas no appreciable change in EC was observed. Compared with control (fallow land), all the soil properties found to be improved under different tree covers at both the depths. Among the different agroforestry tree species, Bambusa vulgaris planted soil showed the higher values of most of the soil properties however lowest values were found under other tree species. Different agroforestry tree species stored 47.18-101.77, 2.39-6.43 and 19.10-35.21 kg ha-1 more available N, P and K, respectively, over the fallow land at soil surface layer where maximum accumulation was found with Bambusa vulgaris for available N and Anthocephalus cadamba for available P and K. Very labile carbon fraction was observed about four and two times higher than less labile and labile and non labile carbon fraction, respectively, where highest amount of non labile carbon fraction was obtained under Dillenia indica plantation soil while other carbon fractions under Bambusa vulgaris plantation at both soil depths. Soil microbial biomass carbon, soil organic carbon content, SOC stock, carbon sequestration rate were higher under Bambusa vulgaris which was 45.08-149.21 μg g-1 of soil, 0.52-3.08 g kg-1 soil, 0.66-3.55 Mg C ha-1 and 0.098-0.586 Mg C ha-1 yr-1, respectively, more than other treatments. Compared to the initial level of 16 years back, available N, P and K, soil organic carbon content and SOC stock in terms of per cent were found to increase and was in the order of available P > SOC content > available N > available K > SOC stock. All the correlations between the soil properties in general were observed as significant. Highest significant positive and negative correlations were observed between SOC and SOC stock (0.991**) and soil bulk density and available N (-0.955**), respectively. Therefore, it is evident from the present study that agroforestry is a suitable land-use system in improvement of soil carbon storage, carbon sequestration as well as for the overall improvement of soil health through improvement in soil properties. The adaptation of Bambusa vulgaris in the agroforestry plantation system in tarai region may be beneficial.EnglishThesis