Biomass and nutrient distribution and their return of Casuarina equisetifolia inoculated with biofertilizers in farm land

An experiment was conducted to study the productivity, nutrient distribution and nutrient cycling of Casuarina equisetifolia Forst in farm forestry. Seedlings inoculated with different biofertilizers such as Azospirillum, Phosphobacterium, AM fungi and Frankia along with their combinations were planted in farmland. Growth, biomass, nutrient distribution, nutrient uptake and nutrient-return through litter were estimated 24 months after planting by harvesting the plant. The height of the tree is ranged from 9.87 to 11.90 m and the girth at breast height (gbh) is ranged from 16.8 to 23.2 cm. The maximum height, gbh and total biomass were obtained in the combined application of Azospirillum, Phosphobacterium, AM and Frankia. The combination of AM + Frankia among double inoculation, and in combination of Azospirillum, AM and Frankia in triple inoculation also proved to be the best treatment in promoting the significant total height, gbh and total biomass production. Better nutrient uptake was estimated in combined inoculation of Azospirillum + Phosphobacterium + AM + Frankia followed by Azospirillum + AM + Frankia in respect of the nutrients such as N, P, K, Ca and Mg. The nutrient concentration was distributed in the order of needle > branch > root nodule > twig > stem > root. Nutrient return in field condition showed the maximum nutrient-return through litter in combination with Azospirillum + Phosphobacterium + AM + Frankia inoculated trees.