施用河道污泥对水稻氮素吸收利用的影响

为了探索污染河道污泥农业资源化利用的有效途径，本研究以河道污泥为研究对象，设计施N量为120、240 kg/hm2 2 个水平，研究河道污泥农田施用对不同生育时期水稻氮素含量、氮素吸收、氮素分配和氮素利用效率的影响。结果表明：（1）施用河道污泥使不同生育时期水稻植株含氮率显著提高，使各生育时期氮素累积量显著提高；（2）使水稻抽穗后氮素在茎鞘中的分配比例显著提高，使水稻抽穗后氮素在叶片和穗中的分配比例明显下降；（3）使不同生育时期水稻氮素干物质生产效率以及氮素籽粒效率均显著或极显著降低，但对水稻氮素收获指数影响不显著；（4）河道污泥×N的互作效应对稻株氮素吸收利用无显著影响。施用河道污泥使水稻植株含氮率、氮素累积量显著增加，而水稻氮素干物质生产效率和氮素籽粒效率则显著降低。

Effects of Dredged Sludge Field Application on Nitrogen Uptake and Utilization in Rice (Oryza. sativa L.)

The paper aims to explore an effective way for agricultural resource utilization of polluted river dredged sludge. A field experiment was conducted taking the dredged sludge from polluted rivers as the research object, and two levels of nitrogen application (120 kg/hm2 and 240 kg/hm2) were arranged to study the effects of dredged sludge application on rice nitrogen (N) concentration, uptake, allocation and use efficiency at different growth stages. The results showed that: (1) dredged sludge increased N concentration and N accumulation in rice plant over the season significantly; (2) dredged sludge significantly improved nitrogen allocation proportions in stems, but obviously decreased that in leaves and spikes of rice after the heading stage; (3) dredged sludge significantly decreased nitrogen-use efficiency for biomass (NUEp) over the season and grain yield (NUEg) at grain maturity, but there had no significant effect on the nitrogen harvest index (NHI); (4) the effect of interactions between dredged sludge×N was not observed for N uptake and utilization at most growth stages of rice. Finally, dredged sludge increased N concentration and N accumulation, but decreased NUEp and NUEg at most growth stages of rice.