Effects of Nitrogen Nutrition on Grain Quality in Upland Rice Zhonghan 3 and Paddy Rice Yangjing 9538 Under Different Cultivation Methods

For evaluating the differences between upland and paddy rice (Oryza sativa L.) as well as interaction between cultivation methods and nitrogen (N) levels, the upland rice cultivar Zhonghan 3 (japonica) and the paddy rice cultivar Yangjing 9538 (japonica) were planted in moist cultivation (MC) and bare dry-cultivation (DC). Each cultivar had 3 N-application treatments (100 kg−1 for low N, 200 kg−1 for normal N, and 300 kg−1 for high N) in MC and DC conditions. Compared with normal N treatment, HN reduced grain yield for both cultivars under DC and for the paddy rice cultivar under MC; whereas, it promoted the yield of upland rice under MC. With the increase of N application rate, the percentage of chalky grain and the chalkiness of upland rice increased under DC, however, the 2 indices were the largest in the normal N treatment and the smallest in the high N treatment under MC; for paddy rice, the percentage of chalky grains and the chalkiness showed a declined trend under DC but an in increased trend under MC. Under both MC and DC, the protein content enhanced in both upland and paddy rice when more N was applied, whereas the amylose content declined. The highest breakdown viscosity and the lowest setback viscosity were observed in upland rice treated with normal N and in paddy rice treated with low N. Compared with MC, DC improved the appearance quality and the nutrient quality of upland rice, and there was no significant variations in other quality indices between upland and paddy rice. The upland rice had better nutrient quality but poorer appearance and cooking qualities than paddy rice. The cooking and nutrient qualities showed lower correlations to the leaf N content in upland rice than paddy rice. These results suggest that the response of upland rice to cultivation method and N level is in great difference to that of paddy rice.

摘 要以粳型陆稻中旱3号和粳型水稻扬粳9538为材料, 设置裸地旱种和水种两种方式及低氮(100 kg hm−2)、常氮(200 kg hm−2)和高氮(300 kg hm−2) 3种氮素水平, 比较了陆稻和水稻米质的差异。结果表明, 旱种高氮处理下陆稻和水稻的产量以及水种高氮处理下水稻的产量较常氮有所下降, 但水种高氮处理下陆稻的产量较常氮增加; 增加施氮量使陆稻的垩白粒率和垩白度均先增加后下降, 两品种稻米的直链淀粉含量下降, 蛋白质含量增加, 而水稻在旱种方式下垩白粒率和垩白度下降, 在水种方式下增加。陆稻以常氮处理及水稻以低氮处理的崩解值最高, 消减值最小。旱种使陆稻外观和营养品质有所改善; 陆稻和水稻旱种的其他品质指标与水种无显著差异。与水稻相比, 陆稻的营养品质较优, 外观和蒸煮品质稍差, 其蒸煮和营养品质指标与叶片含氮率的相关程度较低。表明陆稻和水稻的米质对种植方式和氮素的响应有明显差异。