Litter Production and Nutrient Return in Eucalyptus Hybrid Plantations

Studies on litter production and nutrient return in three Eucalyptus hybrid plantations of ages 5, 7 and 10 years of East Dehra Dun Division were carried out for one year. A total of 3377 kg /ha, 3801 kg/ha and 6207 kg/ha of litter were produced by these three plantations respectively. Of the total litter, leaf litter contributed between 66%;' to 76%, twigs between 16% to 24% and bark between 5% to 10%. Leaf litter, therefore, contributed the bulk of the litter fall followed by twigs and bark. Considering the nutrients in the various litter components at different ages the concentration of all the nutrients (N, P, K, Ca and Mg) was highest in the leaf followed by twigs and bark, except for Mg which showed a higher concenration in the bark than in the leaves and twigs. The concentration of nutrients in all th litter components at all the three also decreases as Ca, N, K, Mg and P; the highest being that of Ca and N and lowest that of P. The total annual return of nutrients in all the three plantations is highest for Ca (49.2, 42.8 and 73.2 kg/ha respectively for 5, 7 and 10 years ages) followed by N (29.8, 32.1 and 59.2 kg/ha), K (15.0, 17.5 and 30.6 kg/ha), Mg (5.0, 6.1 and 9.3 kg/ha), and lowest for P (1.6, 1.9 and 3.9 kg/ha). The maximum amount of all nutrients is returned through leaf litter and lowest through bark.