淮北不同地力水平麦茬田上施氮量对超级稻产量形成的影响

Effects of nitrogen application rate on the yield and yield formation of super rice in rice-wheat double cropping system under different levels of soil fertility in Huaibei region

以江苏淮北稻区稻麦两熟的单季稻为对象,研究了不同地力上的施氮量对超级稻产量及物质生产的影响,为不同地力土壤合理施氮肥提供依据。以该区有代表性的超级稻中熟中粳徐稻3号为供试材料,研究了麦茬田高、中、低3种地力水平上不同施氮量对水稻产量及其构成因素、以及对水稻群体质量的影响。结果表明:施氮量与水稻产量之间呈极显著的二次曲线关系(r高=0.959**,r中=0.971**,r低=0.981**),且高地力土壤水稻产量显著高于中地力土壤,中地力土壤的水稻产量显著高于低地力土壤;不同地力水平上的最高产处理在各个生育期都有相对应较好的群体质量,包括适宜的叶面积指数、合理的茎蘖动态、较高的群体颖花量及花后干物质的积累;在不同地力水平上出现的最高产量,其对应的适宜施氮量分别为260.3、290.7、345.8kg·hm-2。可为该区不同地力下超级稻制定高产适宜施氮量提供依据,3种施氮量在该稻区不同地力示范后分别获得高产,达到了节氮的效果。

Taking the single cropping of rice in rice-wheat double cropping system in the Huaibei region of Jiangsu Province as the object,this paper studied the effects of different nitrogen appli-cation rates on the yield and matter production of super rice under different levels of soil fertility.Super rice Xudao 3,a representative middle-season and middle japonica rice variety in the region,was selected as the test material,and the soils selected had fertility levels of high,medium,and low.The grain yield,yield components,and population traits of Xudao 3 were investigated.There were extremely significant conic relationships between nitrogen application rate and grain yield under three soil fertility levels（rhigh=0.959＊＊,rmiddle=0.971＊＊,rlow=0.981＊＊）.The grain yield was the highest under high level of soil fertility,followed by under medium,and under low level soil fertility.Under different soil fertility levels,the rice population in the treat-ment achieved the highest yield showed better traits,including appropriate leaf area index,rea-sonable tiller dynamics,higher population spikelets,and post-anthesis dry matter accumulation,at different growth stages.The optimal nitrogen application rate achieving the maximum yield un-der the high,medium,and low soil fertility levels was 260.3,290.7,and 345.8 kg·hm-2,re-spectively,which could be used as the recommendation for the optimum nitrogen application rates in Huaibei region of Jiangsu.Through the demonstration experiments in the region,high grain yield and N-saving effect were obtained.