Optimized application of phosphate fertilizer is needed for appropriate growth of zoysiagrass in the soil conditions such as its insolubility and less availability because of soil acidification by repeated cultivation and excessive fertilization. This study was conducted to find out the optimum phosphate fertilization for Zoysia japonica with good quality depending on the growth and chemical changes of the soil in pot and field experiments treated with different levels of phosphate fertilizer. In the pot experiment, the dry weight of shoots and stolons increased as phosphate fertilizer levels increased, and showed no significant difference between 18 and 24 kg N 10a-1. In the field experiment, plant height, fresh and dry weight of shoots, roots, and stolons increased with increasing phosphate fertilizer application, and 12 and 18 kg 10a-1 treated with phosphate fertilizer showed similar growth to 24 kg 10a-1. There was no significant difference in the number of shoots and total of stolons length between phosphate fertilizers 12, 18, and 24 kg 10a-1. The phosphoric acid content in the inorganic nutrient of the zoysiagrass was highest at phosphoric acid 24 kg 10a-1, but potassium, magnesium, and calcium contents were similar at phosphate fertilizer 12, 18, and 24 kg 10a-1. However, as a result of soil investigation, nutrients such as total nitrogen, exchangeable Ca2+ and Mg2+ decreased in phosphate fertilizer 24 kg 10a-1, and excessive phosphate fertilization displayed a tendency to aggravate the soil chemical properties. As a result of considering the growth of the zoysiagrass and the soil environment, the optimum amount of phosphate fertilizer was determined to be 12 kg 10a-1 in
Figures & Tables
Fig. 1.Growth characteristics of zoysiagrass (Zoysia japonica Steud.) depending on phosphate fertilizer application rates in the Wagner pot experiment. Fused superphosphate and potassium chloride were applied at 0, 6, 12, 18 and 24 kg 10a levels each in plots. Urea was applied at 0 and 28 kg 10a levels.