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采用大田试验,以长江中下游地区具有代表性的50个早熟晚粳品种为材料,研究7个氮肥水平(0、150.0、187.5、225.0、262.5、300.0、337.5kghm-2纯氮)下水稻氮和磷积累量、吸收速率、利用效率的差异及其相互关系。结果表明:(1)在0～337.5kghm-2纯氮范围内,随着氮肥水平的增加,早熟晚粳的植株含氮率和氮积累量在拔节、抽穗和成熟期均显著增加;植株含磷率和磷积累量在拔节和抽穗期显著增加,成熟期呈先增后减变化。(2)播种至拔节阶段氮和磷吸收速率随施氮量的增加而提高,差异极显著;拔节至抽穗阶段氮和磷吸收速率随施氮量的增加呈现先增加后降低的变化趋势;抽穗至成熟阶段的氮和磷吸收速率规律不明显。(3)在0～337.5kghm-2纯氮范围内,随着施氮量的增加氮素籽粒生产效率和磷素籽粒生产效率均显著降低(300.0～337.5kghm-2间磷素籽粒生产效率差异不显著),随着施氮量的增加基因型之间的差异减小;随着施氮量的增加氮和磷收获指数都呈现抛物线关系,在施氮量为262.0kghm-2纯氮时出现最大值。(4)早熟晚粳对氮和磷的吸收利用具有显著的协同效应,但随生育进程的推进这种效应减弱。水稻在播种至拔节、拔节至抽穗和抽穗至成熟3个生育阶段的氮和磷吸收速率都呈二次曲线关系(r=0.892**,r=0.736**,r=0.512**)。(5)相关分析表明,产量与拔节期、抽穗期和成熟期的吸氮量和吸磷量以及播种至拔节期和拔节至成熟期的吸氮速率和吸磷速率呈极显著正相关关系。增施氮肥有利于水稻氮和磷吸收利用的提高,但氮肥过高时氮和磷吸收利用不再增加,甚至有所降低。
A field experiment was conducted to study the effects of seven nitrogen application rates (0, 150.0, 187.5, 225.0, 262.5, 300.0, 337.5 kghm-2 pure nitrogen) on rice nitrogen And phosphorus accumulation, absorption rate, utilization efficiency differences and their correlation. The results showed that: (1) In the range of 0 ~ 337.5kghm-2 of pure nitrogen, the nitrogen and nitrogen accumulation of early maturing late japonica rice increased significantly at jointing, heading and maturing stages with the increase of nitrogenous fertilizer level. The accumulation of P and P significantly increased at jointing and heading stage, but increased firstly and then decreased at maturity. (2) The nitrogen and phosphorus uptake rates increased from the sowing stage to the jointing stage with the increase of nitrogen application rate, and the difference was extremely significant. The nitrogen and phosphorus uptake rates at jointing to heading stage increased firstly and then decreased with the increase of nitrogen application rate; The law of absorption rate of nitrogen and phosphorus to the mature stage is not obvious. (3) Within the range of 0 ~ 337.5kghm-2 of pure nitrogen, the nitrogen production efficiency and the phosphorus production efficiency decreased significantly with the increase of nitrogen application rate (300.0 ~ 337.5kghm-2) The difference between the genotypes was decreased with the increase of nitrogen application rate. With the increase of nitrogen application rate, the index of nitrogen and phosphorus harvest showed a parabolic relationship, which appeared when the nitrogen application rate was 262.0 kghm-2 Maximum (4) Early-maturing late Japonica had a significant synergistic effect on the uptake and utilization of nitrogen and phosphorus, but this effect weakened with the advance of the growth process. The nitrogen and phosphorus uptake rates of rice in the three growth stages from sowing to jointing, jointing to heading and heading to maturity all showed a quadratic curve (r = 0.892 **, r = 0.736 **, r = 0.512 **). (5) Correlation analysis showed that there was a significant positive correlation between yield and N uptake and P uptake at jointing stage, heading stage and maturity stage, and N uptake rate and P uptake rate at jointing stage and jointing stage to maturity stage. Increasing nitrogen fertilization was beneficial to the absorption and utilization of nitrogen and phosphorus in rice, but nitrogen and phosphorus uptake and utilization did not increase or even decreased when the nitrogen fertilizer was too high.