【作者】 冯涛；

【导师】 杨京平；

【作者基本信息】 浙江大学 ， 生态学， 2005， 硕士

【摘要】 本文通过研究2003年余杭、2004富阳不同施氮水平对水稻生长变化、器官氮含量、水稻产量、土壤氮累计、渗漏水氮素污染、氮素利用率、最佳经济施氮量影响的基础上,对水稻施氮优化模拟模型(Rice fertilizer-N OptimizationSimulation Model,RNOSM)进行了验证和应用,确定了两地较合理的施氮量和施氮时间。最后对RNOSM 模型的网络化进行探索,建立了模型参数的网络化计算。研究结果如下:1.施氮量与水稻叶面积指数、各器官干物质和植株总重有明显的相关性,随着施氮量的增加,叶面积指数、各器官干物质和植株总重相应增加。在施氮量小于225kghm~-2 时,随着施氮量的增加LAI、绿叶干重、穗重增长明显,但是施氮量高于225kghm~-2之后,增长效果迅速减弱。2.叶N、茎N、根N、穗N含量和施氮量之间都表现为极显著的正相关,相关系数分别为0.9273,0.9374,0.8278,0.9220。3.研究表明一定范围内增施氮肥能够增加水稻产量,但过多施肥会适得其反,导致产量下降。余杭试验表明,施氮量超过225kghm~-2之后水稻产量开始下降。4.通过对两地不同施氮水平下O-20cm土壤全氮含量分析发现,<75kghm~-2的施氮量对土壤氮补充是不够的,过量施肥会引起土壤中氮严重积累,导致环境污染。 从分次施氮的效果看,施肥时间对土壤氮累计影响明显,第一次施肥(基肥)后土壤中氮大量累积,而第二、三、四次间土壤的含氮量变化却不大,因此,从分次施氮的优化考虑,占总施氮量50%的基肥相对偏多,而其后的施肥量有待增加。 从渗漏水与施氮水平的关系看,施氮量大于225 kghm~-2后,地下水含氮量快速增加,从施氮时间看,第一次施肥后渗漏水含氮量很高,适当控制施氮量和减少基肥量对地下水的保护起到积极的作用。5 通过对2003年余杭植株吸氮量、氮肥吸收利用率、氮收获指数、氮盈余等氮素利用指标分析表明,225kghm~-2作为余杭合理施氮量是个较好的选择。更多还原

【Abstract】 The effects of nitrogen fertilizer on the dynamic development of weight and nitrogen of rice organs, yield, N accumulation dynamic in the soil and rice-soil-leakage water system under different N application levels in paddy rice field were conducted inYuhang in 2003 and in Fuhang, 2004. Based on former experiments and our results, a established Rice fertilizer-N Optimization Simulation Model（RNOSM） was used to optimize the nitrogen application amount and time. Furthermore, a web-based simulation module for calculating parameter of RNOSM in Internet was also developed.The experimental and simulated results are shown as follows:1. There was significant correlation between applied nitrogen amount with LAI, dry weights of rice organs. Dry weight of green leaf, panicle and LAI increased quickly with the N application up to 225 kghm^-2, but declined when N supply exceeded 225 kghm^-2 .2. There was significant correlation between nitrogen applied levels with N content in leaf, stem, root, panicle and the coefficient are 0.9273, 0.9374, 0.8278, 0.9220 respectively.3. The yield was increased with N application added among proper range. Extra N application will reduce rice yield. The result inYuhang showed that yield reduced when N application amount exceeded 225 kghm^-24. Nitrogen accumulation dynamic in soil showed that the long-term fertility for rice crop growth could not be sustained when 75 kghm^-2 N applied each year, but when N supply exceeded 225 kghm^-2, surplus nitrogen was accumulated in soil. N accumulation in soil increased quickly and the peak of N content in leakage water appeared after basal nitrogen applied, which implied that basal nitrogen fertilizer being more than 50% of the total applied amount may be the main reason leading to soil nitrogen accumulation and water pollution.5. We suggested 225kghm^-2may be better N application inYuhang considering the N use efficiency6. The optimal economic yield of rice indicated that 199 kghm^-2 , 173kghm^-2 was the reasonable N application to rice variety Bing 9363, Bing 9652 in Yuhang, while 235 kghm^-2 was better N application to Bing 9363 in Fuyang.7. RNOSM simulation showed there was significant correlation between the observed and simulated biomass biomass, N in leaf, N in plant, they accord to "y=x".8. The result of RNOSM optimization showed that at low N application level (75kghm^-2),nitrogen fertilizer should be applied within 40 days after transplanting; at moderate N application level(150 kghm^-2),it should be applied within 55 days after transplanting ;at high N application (>150 kghm^-2),it should be applied within 70 days.9. Based on optimization of 150kghm^-2 in Yuhang , 225kghm^-2in Fuyang ,wesuggested N application should be applied at 10,20,30,45 days after transplanting with the fraction of 20:30:30:20 respectively.10. We developed web-based simulation module for calculating parameter ofRNOSM in Internet, it offered calculating online.更多还原