Abstract:

To provide evidence for optimized N fertilizer application of sugarcane production, the influences of N fertilizer rate on nitrogen absorption and utilization of sugarcane were studied in early growth stage. In this micro-plot experiment, sugarcane varieties ‘ROC22’ was used as experimental materials, and three nitrogen amount were designed with 5.0 g, 2.5 g and 1.5 g 15N-labeled urea/pot at sowing time respectively. The results were as follows: with increase the amount of N fertilizer, nitrogen content, dry matter weight and the N from nitrogen fertilizer in sugarcane and alkali hydrolysis nitrogen and nitrate nitrogen content of soil were significantly increased, while nitrogen utilization rate in sugarcane was significantly decreased. The nitrogen fertilizer application had obviously influenced on fertilizer-nitrogen distribution in sugarcane and soil. In seedling stage, the nitrogen in soil of 20~40 cm depth，especially in 20~30 cm depth was most uptake by sugarcane. At sowing time, the appropriate amount and soil depth of nitrogen fertilizer application should be considered to increase nitrogen utilization efficiency in sugarcane.