Laboratory of Crop Science, Division of Agricultural Botany, Department of Plant resource, Graduate school of Bioresource and Bioenvironmental Sciences, Kyushu University
The objective of this study was to determine the effects of thermophile sewage sludge compost used thermophilic bacteria (Bacillus spp.) on the growth of Manilagrass(Zoysia matrella (L.)Merr.) and on the nutrient leaching losses from the soil by comparison with chemical fertilizer. Thermophile sewage sludge compost (TSSC)/pellet (TSSP) or chemical fertilizer (CF) was aplied to the pots with the soil. TSSC used in this trial were made from sewage sludge at Sanyu Co.,Ltd. in Kagishima, and CF contains 16% of N, P2O5 and K2O respectively. Pellets were made from the compost materials (5mm in diameter). The compost and CF applied were adjusted to the amount of containing 1 or 0.5 g-N per pot. Manilagrass sod was planted on the surface of the pots (1/5000a) in greenhouse snd the sod was harvested repertedly from February to June. Nutrient leaching was determined by measuring its content og solution leached from the soil. The summary of the results is shown below. 1. The biomass above the ground of manilagrass in TSSP and TSSC were less than in CF at early stage, whereas were equivalent with those in CF at last stage. The responces of tiller density to TSSC and CF were simular, but the root biomass in TSSP was larger than that in CF. 2. The total N,NO3-N and K leached from the soil in TSSC were only 1/4 of those in CF treatment. Futhermore, in TSSP, this reoerssive effect of leaching became stronger. The extremely low NO3-N leaching in the compost and its pellets suggested that unfavorable load to the groundwater is negligible when using compost and its pellets as efrtilizer. From these results, it was considered that application of the thermophile sawage sludeg comopst and its pellets were suitable for Manilagrass-sod management as environment-friendly organic fertilizer.