不同氮钾肥施用方法对水稻产量及抗倒伏性的影响

摘要

Rice lodging usual y occurs in the middle and the end of grain fil ing, and it is one of the major elements to affect high and stable yield and good quality. The experiment took Songjing9, a super kind of rice in cold region, as a sample to test the results of different usages of nitrogen and potassium fertilizer towards rice yield and its lodging resistance. The results showed that it was effective to increase the panicles and the grain weight per plant and the number of grains per ear when more nitrogen was used in the early stage of rice growth with the nitrogen application amount 90 kg·hm-2. And it was more effective when less nitrogen was used in the same stage with the amount 135 kg·hm-2. Internode length of the first and the second stems noticeably increased and the flexural strength of stem decreased when more nitrogen was applied in the early stage of rice growth. The influence would be more effective when the nitrogen amount adds up. However, it would be beneficial to strengthen the flexural strength of stems when more potassium and less nitrogen were used in the early planting stage. The nitrogen content of stems obviously increased when more nitrogen were used in the late stage of rice growth;the potassium content thus increased when nitrogen were applied in the early stage, which helped the rice to absorb and accumulate more potassium. The nitrogen content of stems was passively correlated to the internode length, and negatively to the flexural strength. On the contrary, the potassium content of stems was negatively and positively correlated to the internode length, and passively to the flexural strength.%水稻倒伏常发生于籽粒灌浆中后期，是高产、稳产、优质生产的主要限制因素之一。试验选用寒地超级稻品种松粳9号，研究不同氮钾肥施用方法对水稻产量性状及茎秆抗倒特性的影响，为寒地水稻超高产抗倒栽培技术的建立提供理论依据。结果表明，施氮量为90 kg·hm-2时，增加生育前期氮肥施用量有利于提高单株穗数、每穗粒数和单株粒重，但施氮量为135 kg·hm-2时，减少生育前期氮肥施用量，而提高生育后期氮肥施用量更有利于提高单株穗数、每穗粒数和单株粒重；在同等施氮量条件下，增加生育前期氮肥施用量可极显著增加第1和第2节间长度，并降低茎秆抗折力，尤其是施氮量高时这种影响更大；增加氮肥施用量时，相应增加钾肥施用量和减少生育前期氮肥施用量将有利于提高茎秆抗倒特性；增加生育后期氮肥施用量明显提高茎秆全氮含量，而增加生育前期氮肥施用量有利于促进水稻植株钾的吸收和积累，提高茎秆钾含量；茎秆氮含量与节间长度呈显著或极显著正相关，与抗折力呈负相关；茎秆钾含量与节间长度呈显著负相关，与抗折力呈极显著正相关。