CARBON SEQUESTRATION PRODUCTIVITY AND NUTRIENT DISTRIBUTION IN AGROFORESTRY AND FORESTRY MONOCULTURE AND POLYCULTURE LAND USE SYSTEMS OF SUB TEMPERATE MIDHILLS OF HIMACHAL PRADESH

Abstract

newline ABSTRACT newlineThe present investigation on carbon sequestration, productivity and nutrient distribution in agroforestry and forestry (monoculture and polyculture) land use systems of sub-temperate midhills of Himachal Pradesh was carried out in Solan district located at 300 50 30 to 300 52 0 N latitude and 700 8 30 to 770 11 30 E longitude. Agroforestry land use comprises of traditional system whereby trees were present along the boundaries. The trees present were Toona ciliata, Grewia optiva and Bauhinia variegata. Seven crops, namely, Zea mays, Vigna mungo, Brassica campestris, Pisum sativum, Capsicum annuum, Solanum lycopersicum and Triticum aestivum were sown during two years of study. Tree morphology and biomass was studied and it was observed that Toona ciliata, Grewia optiva and Bauhinia variegata had mean dbh of 59.24 cm, 15.36 cm and 22.76 cm and mean height of 20.0 m, 7.85 m and 4.90 m, respectively. Stem wood had the maximum carbon allocation followed by roots, branches and leaves in all the tree species present in agroforestry system. The yield of seven crops varied and in general it was found that crop productivity was less in crops under trees as compared to sole crops. The carbon allocation in the crops also varied during two years of study as the trees affected carbon allocation. Total carbon stock of agroforestry system, including crops was 1123.06 Mg/ha/year and it sequestered 4121.64 Mg/ha/year of carbon. However, since the crop is harvested out of system, the carbon sequestered by the trees is 144.67 Mg/ha/year. In another two land use systems the monoculture had Pinus roxburghii while polyculture forestry system had P. roxburghii along with Bauhinia variegata, Quercus leucotricophora and Toona ciliata. Tree height and dbh of Pinus roxburghii in monoculture was 20.58 m and 20.30 cm while in polyculture land use system average height and dbh was 13.94 m and 51.96 cm, respectively. Soil was analysed for various physico-chemical parameters in all the three land use systems. It wa