Effect of Soil Conditioners on Soil Moisture and Growth of Manila Grass (Zoysia matrella) on Fairway of Bangpoo Golf Country Club

Abstract

The experiment was conducted on a fairway of Bangpoo Golf Country Club objectively to investigate the effects of perlite, bentonite, pumice and gypsum at the rates of 50, 100 and 200 kg/rai on the growth and quality of Manila grass (Zoysia matrella), soil moisture content and changes to soil properties. The Manila grass was approximately 20 years old prior to the experiment. The results revealed that the application of soil conditioners enhanced the growth and quality of Manila grass which can clearly be seen during the no-irrigation period. The addition of bentonite at the rate of 50 kg/rai significantly gave the highest weight of cut grass of 143 kg/rai, and also the best quality considering the steady growth, density and green color. Other soil conditioners such as perlite, gypsum and pumice similarly boosted the growth of Manila grass, but required the use of larger amounts than that of bentonite. Besides, perlite tended to induce the succulence of grass better than did other soil conditioners. In the grass and its residue layer of all treatments, the contents of organic matter, total nitrogen, available phosphorus and available potassium were not different. All had high to very high levels, ranging between 33-40 g/kg, 5.2-9.3 g/kg, 97-181 mg/kg and 213-366 mg/kg, respectively. The application of bentonite resulted in the highest acidity with the pH of 7.4 in the sand layer when compared to other soil conditioners, especially when applied at the rate of 50 kg/rai. This also tended to maintain the highest amounts of organic matter (22.6 g/kg), total nitrogen (1.2 g/kg), and avail-able phosphorus (137.5 mg/kg) in the layer. Adding pumice, especially at the rate of 200 kg/rai, tended to preserve the lowest amounts of organic matter and plant nutrients in the sand layer, but tended to maintain more soil moisture than did other soil conditioners, particularly when applied at the rate of 100 kg/rai. On the other hand, perlite and gypsum were similar in terms of the effects on organic matter and plant nutrients in the sand layer.