Evaluation of soil fertility status and nutrient return from the important indigenous Agroforestry tree species in Himachal Pradesh with special reference to Hamirpur district.

Principal Investigator: Dr.V.P Panwar, Scientist-D
Duration: 5 Years (1st April, 2006 to 31st March, 2011)

Six important agroforestry species namely Grewia optiva, Mours alba, Celtis australis, Bauhinia variegata, Albizia chinensis, Toona ciliata were studied under the project. Quantitative analysis of existing plant species in farm land in district Hamirpur of Himachal Pradesh showed composition of twenty two (22) agroforestry tree species. The tree density of G. optiva was highest (0.220 trees/100 m2) with basal cover of 4.80 cm2/100 m2. Highest basal cover of (9.40 cm2/100 m2) and IVI (57.44) have been recorded for T. ciliata as compared to other associates. Monthly litter-fall have been worked out for all the species and nutrient contents in litter for all the species has been analyzed. The average production of annual litter-fall was highest in A. chinensis (314.98 g/m2/yr) and the least was recorded from C. australis (146.01 g/m2/yr). Nutrient concentration in leaf litter varied as: Ca > N > K > Mg > P. On an average about 35 per cent in A. chinensis and T. ciliata; 40 per cent in C. australis and G. optiva; 47 per cent in B. variegata; 60 per cent in M. alba; of nitrogen, phosphorus and potassium contents were translocated out of the leaves before their fall. Relative abundance of the total return of nutrients (annual) was in the order of: Ca > N > K > Mg > P. The annual average nutrient return nutrient return was noticed highest (13.27 g/m2/yr) in case of A. chinensis and 6.39 g/m2/yr (lowest) for C. australis. The N, Ca & P contents returned about 87 to 91 per cent of the total nutrients. Overall, soil reaction was nearly neutral under all the vegetations with lesser variability which showed pH stability. Bulk density was observed lower in the soils under different vegetations as compared to control in all the depths. Under the vegetations higher organic matter was recorded. Organic carbon and organic matter was higher in the soils under different vegetation as compared to control. Overall soil quality was found to be good under agroforestry species.