BHARDWAJ, D.R.CHISANGA, KAFULA2017-01-092017-01-09201247736http://krishikosh.egranth.ac.in/handle/1/95216ABSTRACT The present investigations entitled “Carbon storage potential and bio-economic appraisal of different land use systems in dry temperate north western Himalayas” were carried out through experiments at different altitudinal gradients in Kinnaur district of Himachal Pradesh. These experiments were laid out in Randomized Block Design (Factorial). The present investigations were conducted to assess the biological yield, carbon stock and economic returns from the different land use systems along an altitudinal gradient and to identify suitable land use systems with high monetary return and carbon storage potential in dry temperate north-western Himalayas. Three altitudinal gradients were considered for the study viz; 1900-2170m, 2170-2440m and 2440-2710m a.s.l. In each altitudinal gradient six land use systems i.e, agriculture, horticulture, agri-horticulture, agri-hort-silviculture, silvipastural and barren land which were common to all the three altitudinal levels were selected. The total tree biomass was the sum of stem biomass, branch biomass and leaf biomass. The plot size for trees was 50 m x 20 m. The tree biomass was converted into carbon fraction by factor of 0.5 (IPCC default value). Crop, shrubs, grass biomass and litter biomass were estimated with the help of a 1 square metre plot. Soil attributes viz; bulk density, organic carbon and available nitrogen were also analyzed. Data concerning economics of the land use systems was collected through interviews with the farmers, published literature and Krishvigyan Kendra resource person of the study area. The results have revealed that different land use systems have significant influence on the production of above, below and total biomass, carbon density (t ha-1), financial returns, expenses, net-profit and benefits-cost ratio. Maximum above ground biomass (84.65 t ha-1), below ground biomass (19.50 t ha-1) and total biomass (104.10 t ha-1) was recorded in the silvi-pasture (T5) land use system. Total biomass production of different land use systems followed the order: silvipasture > agri-horti-silviculture > agrihorticulture > horticulture > agriculture > barren land, respectively. This trend is same for carbon density (t ha-1), of different land use systems. In the effect of altitudinal ranges, the above ground biomass, below ground biomass, total biomass and carbon stock, irrespective of land use systems increased with the increase in altitudinal level. Soil physico-chemical analysis revealed that there is significant variation due to bulk density, organic carbon and available nitrogen in different soil layers of different land use systems. The value of SOC and available N decreases with increase in depth, but it increases with increase in altitudinal level. Maximum soil carbon density (155.77t ha-1) in (0-100cm) layer was in agri-horticulture land use system. Maximum total (soil+plant) ecosystem carbon density followed the trend agri-horticulture > agri-horti-silviculture > silvi-pasture > horticulture > agriculture > barren land, respectively in descending order. The maximum soil:plant carbon density ratio (23.10 t ha-1) was recorded in agriculture land use system which was found to be significantly higher than all other land use systems under investigation. Rate of gross return was maximum (Rs 18,23,000) in agri-horticulture system, which was closely followed by the land use systems of horticulture, agri-horti-silviculture, silvi-pasture system, agriculture and barren land, respectively in the descending order. Irrespective of land use systems rate of gross return increases with the increase in altitudinal levels. Maximum expenses followed the order: agri-horticulture > horticulture > agri-horti-silviculture > agriculture > silvi-pasture > barren land, respectively. Maximum net profit was attained by agri-horticulture system (Rs, 13,10,000), which was closely followed by horticulture (Rs 11,65,852), only. Net returns as achieved in other land use systems viz., agriculture, silvi-pasture and barren land were quite low in comparison to fruit based land use systems. In altitudinal ranges, the net profit obtained increased appreciably from A1 to A3. A3 altitudinal range had the highest net profit. Benefit-cost ratio was maximum (6.63) in the silvipasture based land use system, which was closely followed by the land use systems of barren land (4.73), horticulture (3.93), agri-horticulture (3.50) and agriculture (1.41), respectively, in the descending order. From this finding we can conclude that agri-horticulture systems are better land use option because not only do they provide very high returns but also increases the carbon storage potential as well as fertility status (% C and N) in comparison to other land use systems in general and agriculture in particular.enThesis