广西旱地耕作体系缓释氮肥效应试验研究

1998－2000年分别在广西的崇左县、南宁市郊区、来宾县等地进行甘蔗、龙眼、玉米施用不同缓释（或长效）氮肥的田间试验研究。试验采用常规肥料试验方法，甘蔗、玉米均设5个处理：对照（不施氮肥）、普通尿素、涂层尿素、长效碳铵、缓释尿素；龙眼除不设不施氮肥处理外，其余处理与甘蔗、玉米相同；各试验均设4次重复。结果表明，涂层尿素、缓释尿素分别比普通尿素增加原料蔗11．7％和5．3％，每公顷增糖1262kg和497kg，增糖率13．6％和5．3％；甘蔗当季对涂层尿素与缓释尿素中氮素的利用率分别此普通尿素高7．50％和2．85％（绝对值）。施用涂层尿素、缓释尿素和缓释碳铵的龙眼幼年树生长量与普通尿素处理无显著差异（F＞0．01）；施用涂层尿素的龙眼果实产量比普通尿素增产2．5％－13．6％。玉米施用缓释氮肥比施用普通尿素增产337．5－525．0kg/hm^2，增产率5．36％－7．74％；玉米施用缓释尿素、涂层尿素的氮素利用率比普通尿素分别提高5．14％、4．39％（绝对值）。缓释氮肥对甘蔗、龙眼、玉米有良好的供肥性，适用于氮素淋溶强烈的广西土壤。

Effect of Slow Releasing Fertilizers in the Upland Cropping System in Guangxi

The field trials of fertilization on sugarcane,longan and corn with different slow releasing nitrogen fertilizers are conducted in the areas of Chongzuo,Nanning outskirt,Laibin in Guangxi,south China from 1998 to 2000. The sugarcane and corn were treated with urea,the coated urea,slow releasing ammonium bicarbonate,slow releasing urea and control (without nitrogen fertilizer). Longan was treated with the same as both sugarcane and corn except for no treatment of non nitrogen fertilizer. All treatments were repeated four times. Compared with the urea,the coated urea and slow releasing urea increased sugarcane yield by 11.7% and 5.3%,and sugar by 262 kg/ha and 497 kg/ha,with increase of 13.6% and 5.3%,respectively. The utility of the coated urea and slow releasing urea by sugarcane were 7.50% and 2.85% respectively higher than the urea in the current growing season. The growth increment of longan young trees in the urea treatment has no significantly difference (F>0.01) from that in the coated urea, the slow releasing urea and slow releasing ammonium bicarbonate. But the fruit yield of longan in the coasted urea was 2.5% to 13.6% higher than the urea. The corn yield in the slow releasing urea was 337.5 to 525.0 kg/ha higher than the urea,increasing 5.36% to 7.74%. The utility of nitrogen in the slow releasing urea and the coasted urea by corn was 5.14% and 4.39% respectively higher than the urea. It suggests that the slow releasing nitrogen fertilizers could supply nitrogen continually,and improve the growth and development of suarcane,longan and corn. The slow releasing nitrogen fertilizers should be promoted to be used in the earth of Guangxi area.