龙州县河谷地区甘蔗适宜施氮量研究

The Study of Suitable Nitrogen Fertilizer Rate with Sugarcane in Valley Area of Longzhou

合理的甘蔗氮肥施用量能减少蔗田由于过量的化学肥料投入而造成的生态破坏。本文于2017~2019年通过1新1宿田间定位试验研究了不同施氮量对甘蔗农艺性状、产量、糖分等的影响。试验在崇左龙州县设置了6个不同施氮量处理,分别为施纯氮0、225、300、375、450、600(常规施氮量)kg/hm^2。甘蔗伸长期采用叶绿素仪测定叶片SPAD值和氮素含量,收获期测定甘蔗产量、锤度、株高、茎径等性状。结果表明:施用氮肥能使甘蔗产量和产糖量显著增产,施氮量为300kg/hm^2(N2)时甘蔗产量和产糖量最大,1新1宿平均产量和产糖量分别为80296、10889kg/hm^2。不同施氮处理对甘蔗糖分则无显著影响,但当施氮量低于225kg/hm^2后,宿根年的产糖量将显著下降。在甘蔗氮素利用方面,施氮能提高伸长期叶片SPAD值和氮含量;氮肥农学利用率、氮肥偏生产力、氮肥产糖力随着氮肥的增加而逐渐下降。“线性+平台”模型能完整地模拟产量与氮肥的肥效关系。龙州县河谷地区甘蔗生产上推荐的氮肥施用量为300~375kg/hm^2,这比常规施肥减少了37.5%~50%的氮肥用量,同时能稳定甘蔗的后续生产,这对节省甘蔗生产成本和减少农田面源污染有着重要意义。

Reasonable nitrogen application can reduce the ecological damage caused by excessive chemical fertilizer input in sugarcane field. An experiment was fixed in valley area of Longzhou to study the effects on agronomic characters, yield and sugar content of sugarcane by different nitrogen rates. It was set 6 treatments with different nitrogen application amounts, included 0, 225, 300, 375, 450, 600(conventional fertilizer application) kg/hm 2 in the county of Longzhou, Chongzuo by 1 new-plant 1 ratoon trial in 2017~2019. Chlorophyll value (SPAD) and nitrogen content were measured by chlorophyll meter in the stage of sugarcane elongation, and yield, hammer degree, plant height and stem diameter of sugarcane were determined at the harvest period. The results showed that the sugarcane yield and sugar yield were increased significantly by applying nitrogen fertilizer, the sugarcane yield was 80296 and sugar yield was 10889 kg/hm^2 with 1 new-plant 1 ratoon average, when the nitrogen fertilizer was 300 kg/hm^2;It had no significant promote effect on sugar content by different nitrogen treatments, but the sugar yield of second years was decreased significantly after the nitrogen application amount was belowed 225 kg/hm^2 . Nitrogen application could improve SPAD value and nitrogen content of leaves in the period of elongated. Nitrogen Agronomy Utilization Efficiency, Partial Factor Productivity, and Sugar Partial Factor Productivity decreased gradually as nitrogen fertilizer increased. The relationship between yield and nitrogen fertilizer could be simulated by “linear+platform” model. The optimum amount of fertilization was 300~375 kg/hm^2 in valley area of Longzhou, and the amount of nitrogen fertilizer was less to 37.5%~50% than conventional fertilizer application, it was ensuring normal nitrogen supply for subsequent production. It is the key to saving cost of sugarcane production and reducing agriculture non-point source pollution.