Effects of Application of Powdered Charcoal and Inorganic Fertilizer On Carbon Sequestration In Forest Soil and Growth Patterns of Quercus Serrata and Cryptomeria Japonica In Western Japan.

Although various techniques for producing woody charcoal are available, their effects on forest ecological functions need to be known for optimum application method. Charcoal has high density and chemically stable forms of carbon which can survive in soils for thousands of years. Kinki University‘s Satoyama forest comprising mainly Quercus serrata in ridge position and Cryptomeria japonica in valley bottom and used as the site for ecological engineering experiments was selected. The objective was to determine the effects of powdered charcoal, nitrogen and phosphorous application on soil physico-chemical and biological nature, carbon sequestration, tree growth patterns including sprout regeneration, litterfall phenology and stream water quality. Before starting this experiment soil physico-chemical and biological nature as well as tree growth rate, litterfall phenology, and stream water quality and hydrology were monitored during 2007-2010.

On the ridge position, two groups of 18 Quercus serrata trees with diameter at breast height (DBH) of 20-30 and 30-50 cm were selected from an area of about 0.5 ha. From the valley bottom there were 15 and 12 trees of Cryptomeria Japonica in the corresponding two groups. Powdered charcoal from coniferous tree, nitrogen as slow-release coated urea, and phosphorus as calcium superphosphate were applied and mixed 5 cm deep after removing litter layers. They were applied at 6 t/ha in carbon equivalent for charcoal, 140 kg/ha for nitrogen and 30 kg/ha for phosphorus at the forest floor surrounding tree trunk on an area of 16 and 25 m² for trees with DBH of 20-30 and 30-50 cm, respectively. The forest floors were thereafter covered with litter layers to protect the topsoil. There were four replications for Quercus serrata and three replications for Cryptomeria japonica. The set-up was established during February-March 2011. The presentation will discuss the results of the first growing season spanning April to October 2011.