减氮控磷稳钾施肥对水稻产量及养分积累的影响

氮、 磷用量偏大，钾肥用量不足不仅影响水稻的正常生长发育，而且导致养分利用率偏低。本文通过田间试验，研究减量施用氮、 磷肥，稳定钾肥投入对水稻产量、 养分积累量和肥料利用率的影响。试验设14个处理，每个处理重复2次。结果表明，氮钾、 磷钾、 氮磷钾配施处理的水稻秸秆生物量和籽粒产量均显著高于不施肥处理（P0.05）; 减氮控磷稳钾处理（N 225 kg/hm2、 P2O5 60 kg/hm2、 K2O 90 kg/hm2）与常规施肥处理相比（N 300 kg/hm2、 P2O5 150 kg/hm2、 K2O 60 kg/hm2）能显著增加水稻秸秆生物量（P0.05），明显提高千粒重和籽粒产量; 试验还得出，减氮控磷稳钾处理分蘖期地上部氮、 钾含量和秸秆氮、 钾含量显著高于常规施肥处理（P0.05）; 收获期地上部氮、 钾的积累量和氮、 磷的表观利用率显著大于常规施肥处理（P0.05）。适当减少氮、 磷用量， 增加钾肥用量能改善氮、 钾营养状况，促进地上部干物质的积累，提高籽粒产量和氮、 磷表观利用率。N 196.2 kg/hm2、 P2O5 46.5 kg/hm2、 K2O 90 kg/hm2的配施方案具有实际推广应用价值。

Effects of fertilization with reducing nitrogen, controlling phosphorus and stabilizing potassium on rice yield and nutrient accumulation

Excessive application of nitrogen and phosphorus and lower potassium supply not only limit rice growth, but also reduce nutrient use efficiency. In this paper, a field experiment was conducted to study the effects of reducing nitrogen and phosphorus dosages and stabilizing potassium supply on rice yield, nutrient accumulation and fertilizer use efficiency. There were fourteen treatments with two replications. The results indicate that the straw biomass and grain yields of the treatments with integrated N-K, P-K, or N-P-K applications are significantly (P0.05) higher than those of the no fertilizer treatment. The straw biomass of the treatment with less nitrogen and phosphorus and more potassium application (T11, modified treatment, N 225 kg/ha，P2O5 60 kg/ha and K2O 90 kg/ha) is significantly (P0.05) higher than that of the conventional fertilization treatment (CFA, N 300 kg/ha， P2O5 150 kg/ha，K2O 60 kg/ha ) and the differences of kernel weight and grain yield between the two treatments are obvious. The nitrogen and potassium contents in shoots at the tillering stage and in straw at the harvest stage, the accumulated nitrogen and potassium amounts in above ground organs at the harvest stage, as well as apparent nitrogen and phosphorus use efficiencies of the modified treatment are significantly (P0.05) higher than those of CFA. These results imply that properly reducing nitrogen and phosphorus dosages, and increasing potassium dosages could catch nitrogen and potassium need of rice plants, increase dry matter accumulation and grain yield, and improve apparent nitrogen and phosphorus use efficiencies. The fertilization scheme of N 196.2 kg/ha, P2O5 46.5 kg/ha and K2O 90 kg/ha should be recommended for practical rice production under local conditions.