Soil carbon stock and nutrient study in different agroforestry systems at kinnaur district, himachal pradesh

The present study was undertaken at Kinnaur district of Himachal Pradesh. The study focused on Soil carbon stock and nutrient analysis under three different agroforestry systems viz, Agri-horticulture system AH, Agrisilviculture system AS and Agrihortisilviculture system AHS of North-Western Himalayas during the year of 2014-15. The laboratory tests of soil showed that the organic carbon, extractable phosphorus, calcium and magnesium decreased with an increase in soil depth. Under the physical properties, the reverse trend was observed for bulk density. Bulk density 1.34 g cm3 was higher in the AS system. Maximum bulk density 1.47 g cm3 was recorded at 15-30 cm depth whereas minimum bulk density 1.20 g cm3 observed at 0-15 cm depth. Particle density 2.49 g cm3 was significantly higher in the agrihorticulture system. The pore space percent 46.99% was significantly higher in the agrisilviculture system while the pore space percent 48.90% was significantly higher at surface soil. Particle density 2.48 g cm3 was significantly higher at 0-15 cm depth. Chemical parameters were found decreasing with increasing soil depth. Organic carbon 1.26% was significantly higher in the agrihortisilviculture system. Organic carbon 1.26% was significantly higher at 0-15 cm depth in high hills temperate dry and cold C2 climatic conditions. Similarly exchangeable Ca 5.52 mg/100g was significantly higher in the AHS system. Exchangeable calcium 6.03 mg/100g was significantly higher at 0-15cm depth. Most of the soil samples were alkaline property. Maximum soil pH 8.21 was recorded in high hills temperate dry and cold C2 climatic conditions which significantly differed with C1 climatic condition. The deep soil layer 15-30 cm showed maximum pH. N (0.25%), P (0.97 mg/100g) and K (1.69 mg/100g) was significantly higher at upper (015 cm) layer of soil. Therefore in the present study, an attempt was made to compare the soil Physico-chemical properties under two different climatic conditions dry temperate high hills C1 and High hills temperate dry and cold C2 climatic conditions and their effect on agroforestry systems. Result reveals that C density was higher in 58.75 t ha -1 AHS system followed by AH system 56.34 t ha -1 and AS system 52.04 t ha -1. Carbon density was maximum in C1 climatic condition with comparison to C2 climatic condition.