氮肥运筹对超级杂交粳稻产量、品质及氮素利用率的影响

在高产施氮量条件下(225 kg hm-2),按基蘖肥、穗肥不同施氮比例且穗肥依不同叶龄期追氮共设计了20种施氮模式,研究了其对超级杂交粳稻常优1号产量、氮素利用率及主要米质性状的影响。结果表明:氮肥运筹对常优1号产量影响极大,基蘖肥与穗肥施氮比例为58.34∶41.66,穗肥以叶龄余数4、2叶等量施氮时,产量最高;产量与总吸氮量、氮肥农学利用率、氮肥表观利用率、生理利用率呈极显著正相关关系,氮收获指数和百千克籽粒需氮量与产量呈二次曲线关系;随着穗肥施氮比例的下降,稻米整精米率、蛋白质含量、垩白率、垩白度逐渐下降;胶稠度、直链淀粉含量呈直线上升趋势;穗肥随追肥叶龄期推迟,整精米率、蛋白质含量提高,而直链淀粉含量下降。胶稠度、外观品质因基蘖肥施氮比例的不同而异。综合来看,基蘖肥、穗肥施氮比例为6∶4,穗肥以倒4、2叶期追肥可使该品种超高产、优质、高效得到较好的协调统一。

Effects of Nitrogen Application Regimes on Yield, Quality, and Nitrogen Use Efficiency of Super Japonica Hybrid Rice

Effects of nitrogen application regimes,based on the proportion of base-tillering fertilizer to panicle fertilizer and leaf age of panicle fertilizer supply,were studied on yield,nitrogen use efficiency and quality in supper japonica hybrid rice,cv.Changyou 1,under the high grain yield at 225 kg ha-1 of N condition during a whole growth stage.The result indicated that the yield was influenced significantly by nitrogen application regimes.The regime for highest yield was that the ratio of base-tillering fertilizer to panicle fertilizer was 58.34:41.66,and the split panicle fertilizers were equally applicated at fourth and second leaf age from top.There were highly significantly positive correlations between yield and total N uptake,agronomic N use efficiency,apparent N recovery efficiency,physiological N use efficiency,and significantly quadratic relationships between yield and kg N 100 kg-1 grain yield,N harvest index. With the decreasing of N rate of panicle fertilizer,head milled rice,protein content,chalky ratio and chalkiness were decreased;gel consistency and amylose content increased gradually.With postponing the time of N-applying leaf age,head milled rice and protein content were raised,and amylose content dropped.The gel consistency and apparent features were varied by different application proportions. On the whole,the proportion of N-application at 6:4 and the top dressing of panicle N-fertilizers with equal amount at fourth and second leaf age from top might realize the coordination of supper high-yield,good quality,and high N use efficiency.