The Effects of Slurry and Urea Fertilization Levels Application on Productivity of Orchardgrass and NO$_3$-N Content of Soil

This experiment was conducted to investigate the productivity in permanent orchardgrass grasslandaccording to the urea fertilization levels of 0, 100, 200 kg N/ha and the animal excreta fertilizationlevels of 0, 40, 80, 160 kg N/ha on the basis of N contents respectively and -N content of thesoil.The results were obtained as follows;1. The productivity of grassland was significantly increased by the increase of the excreta fertilizationlevels until the urea-N level fertilization of 100 kg/ha but repressed and reduced by the increaseto I60 kg/ha lcvel of the animal excreta fertilization at urea-N fertilization level of 200 kg/ha.2. Averaged seasonal productivity of the animal excreta N was decreased in first and third cutting timeand was increased in second cutting time according to the increase of urea-N fertilization.3. The increase of urea-N and animal excreta N increased the content of crude protein but the fertilizationeffect of urea-N was higher than that of animal excreta N.4. The total yield of N was continuously increased at both of the urea-N and animal excreta N butthe pure yield of N was decreased according to the increase of N fertilization and showed -63.1kg/ha at the fertilization of the urea-N of 200 kg N/ha and animal excreta N of I60 kg/ha.5. -N content of the soil of orchardgrass glassland established one year previously was no differenceamong the N variety and fertilization levels but was increased to the order of summer, autumn andwinter. The highest content of -N was mcasured in winter with the value of 34.9 ppm.