Increasing use of green spaces for park and golf land in Japan leads to manage large quantities of plant residues, such as grass clippings and pruning branches. Generally, these residues are transported and incinerated in large plants at the expense of a large amount of fuel and energy. Time and space-saving processes are of interest in treating the biomass. Steam-treatment (hydrolysis method using high temperature, 205^oC, and high pressure steam, 1.6 MPaG) can reduce the volume of fresh plant residues and its application to soil can be highly useful. The main objective of this study was to evaluate the effect of steam-treated grass clipping and the liquid residues deriving from the treatment plant on grass growth, drainage water quality and changes in soil bio-chemical properties after incorporation into a simulated golf course. A plastic container (L: 47.0 x W: 40.0 x D: 22.5 cm) was taken where the surface soil (10 cm) was a mixture of andosol and sand (3:2 volume) and the subsurface soil (10 cm) was andosol only. A basal dose of chemical fertilizer (25 g m^-2 of NPK: 8-8-8) and poultry manure (20 g m^-2) was applied. The main treatments were: CF (25 kg m^-2 of NPK: 8-8-8, topdressing after 1 month), LL (1 kg m^-2 of commercial leaf litter), GT (1 kg m^-2 of treated-grass), GT+BL (1 kg m^-2 of treated-grass plus 6 L of liquid residue in single application as basal only), GT+FL (1 kg m^-2 of grass-treated plus 3.2 L of liquid residue, diluted 10 times and applied six times as fetigation), and GT10 (10 kg m^-2 of treated-grass). Clipping yield was recorded twice both in 2004 and 2005. All treatments received only chemical fertilizer (25 kg m^-2 of NPK: 8-8-8, as topdressing) in 2005. At the end of this experiment, the soil was sampled to determine the chemical and biochemical properties. Dry matter yield of clipping was observed to be the highest for GT10 and the lowest for CF, in both the years. The clipping yields for other treatments were statistically identical. The liquid residue did not contribute to grass growth. A little visual damage with GT+BL was observed and GT+FL had slightly negative effect during second cutting, probably relating to the low pH (4.5) of this liquid residue. Irrespective of treatments, the pH of drainage water varied from 6.5 to 7.5. Only the EC in GT10 increased from 1.9 (first sampling) to 2.5 (third sampling) dS m^-1 and decreased from 1.5 to < 1.0 dS m^-1 for other treatments. During the first sample, the nitrate concentrations in drainage water for all treatments were above the permissible level (> 10 mg N L^-1) where GT10 had the lowest level. From second sampling onwards, all treatments had value lower than 10 mg N L^-1. Irrespective of treatments, ion phosphate was not detected probably due to the high adsorbed capacity of this element by andosol. Soil microbial biomass carbon, soil respiration, dehydrogenase and soil enzymatic activities (protease and phosphatase) were higher in GT10, followed by GT and LL, than in CF. The GT10 showed the lowest qCO₂, indicating a greater carbon use efficiency compared to other treatments. Results suggest that the steam-treatment can be an alternative method of grass clipping recycling by enhancing microbiological activities and thus, reducing the application of a large amount of chemical fertilizers. However, a long-term study is needed to make concluding remarks on the application of steam-treatment as a better and cost-effective alternative technology to incineration.