摘要： 3种供试水稻品种的营养需求存在差异，生育期间吸收氮、磷、钾的绝对量以郑稻6号最多，黄金晴最少；郑稻6号对氮的吸收积累在生育中前期相对较低，在抽穗至成熟阶段相对较高。因此，施肥时应充分考虑品种需肥特点，以保证高产高效。水稻叶色与施氮量相关，低氮时水稻倒二叶叶色值（SPAD）变幅为41.8~22.1，中等施氮量时为44.3~26.4，而高氮量时为44.6~32.3。采用中等施氮量（N225.0）时，水稻齐穗前叶色值一直保持在37以上，且后期叶色绿而不浓。因此认为，水稻齐穗前倒二叶SPAD值37可作为是否追施氮肥的参考指标。

关键词: 沿黄地区, 水稻, 需肥规律, 叶色

Abstract: The nutrition characters, leaf colour of 3 rice varieties and their nitrogen fertilization techniques were studied in the area along the Yellow river. The results indicated that the amount of N, P and K absorbed by the tried varieties of rice was different during the period of growth. The absolute absorption amount of N, P and K was the most for Zhengdao 6, and the least for Huangjinqing. The N accumulation amount of Zhengdao 6 was less at the early middle stage and more from earing stage to mature stage, compared to the other tried varieties. Therefore, the nutrition characters of rice should be considered when applying nitrogen for ensuring the high yield of rice and high nitrogen efficiency. There was closely relationship between the second-top leaf color of rice and the application rate of nitrogen fertilizer. The SPAD value changed from 41.8 to 22.1 as the low amount of nitrogen fertilizer (112.5 kg/ha)was used, and it changed from 44.3 to 26.4 in the middle amount of N(225.0 kg/ha)application and from 44.1 to 32.3 in the high amount of N (450.0 kg/ha)application. The SPAD value of rice second-top leaf could maintain 37 and above before the ear-filling stage, especially the leaves maintained green and not too rich at the later stage when the middle amount of N (225.0 kg/ha)was applicated. So, 37, the SPAD value of the second-top leaf before the ear-filling stage could be a reference index of the nitrogen fertilizer application.

Key words: The area along the Yellow River, Nutrition character, Leaf color