Fertilizer use plays an important role in crop production to ensure food security in China. At the same time, the relatively low nutrient use efficiency resulted in negative impact on environment quality. Therefore, scientific use of nutrient resources and improvement in fertilizer use efficiency is an important scientific issue rated to national food security and environment quality. This review paper discussed China’s basic situation with large population, limited arable land, relatively low land productivity and fragile ecosystem, analyzed fertilizer demand to meet the rapid increase in crop production, overviewed current use of organic and inorganic nutrient resources, and revealed N loss from chemical fertilizer application and its impact on environment. Based on deep understanding of the existing problems and great challenge China is facing, the authors proposed a new fertilizer recommendation strategy-“regional fertilizer rate control with adjustment at field level”, developed regionalized nutrient management for small size farm operation system and precision fertilization for large scale farm operation. The current situation and existing problems in slow/controlled release fertilizers and in organic nutrient resources were also discussed. For sustained increase in crop production to support food security and to protect the environment, the technic strategy was proposed, including increase of land productivity, improvement of all nutrient resources using advanced science and technology, realization of regionalized fertilizer recommendation based on land productivity. Favorable policies and continuous financial support to fertilizer related science and technology development was also suggested.

肥料在保障我国粮食安全中起着不可替代的支撑作用，同时化肥养分利用率低又产生了对环境的不良影响。因此用好肥料资源、提高肥料利用效率是关系到国家粮食安全和环境质量的重大科技问题。本文实事求是地分析了我国人多、地少、耕地质量差、农田生态环境脆弱的基本国情和肥料领域面临的严重挑战；对国家种植业发展对肥料的需求，有机养分和化肥利用现状和问题、农田中化学氮肥的损失及其对环境的影响等问题进行了较为全面地综述；提出了“区域用量控制与田块微调相结合”的推荐施肥的理念和技术路线；形成和发展了适合分散经营和规模经营的分区养分管理和精准施肥技术体系；同时对新型肥料和有机养分资源在我国研究应用的现状和存在的问题进行了分析评述。在此基础上，提出了提高耕地综合生产能力、依靠科技进步高效利用肥料资源、按照增产潜力做好施肥区域布局等技术政策，建议针对肥料科学技术的发展形成稳定的政策支持和保障。

【Objective】Rice is one of the most important food crops in China. Continuous realization of high yield has a great significance in ensuring food security and society stability. Meanwhile, low nutrient use efficiency is a serious problem in rice production in China. The objective of this study was to investigate if a cultivation technique could coordinately increase both grain yield and nutrient use efficiency of rice. 【Method】 The japonica hybrid rice cultivar Changyou 3 was used and six cultivation patterns were conducted. No nitrogen application (0N)，local high-yielding cultivation (control), high-yielding and high efficiency cultivation (HHC), super high-yielding cultivation (SHC), super high efficiency cultivation (SHE) and stable yield and high efficiency cultivation (SYHE) were designed. The characteristics of grain yield formation under different cultivation patterns and their nutrient absorption and utilization efficiencies were analyzed. 【Result】 The results showed that the average yields of HHC, SHC,SHE and SYHE were 9.5, 11.5, 10.7 and 9.0 t?hm-2, respectively, and 14.5%, 38.6%, 28.9% and 8.4% higher than the control. Nitrogen recovery efficiency was increased by 39.5%, 93.9%, 86.1%, and 31.0%, and nitrogen agronomic efficiency was increased by 66.5%, 84.4%, 98.2% and 70.1% under HHC, SHC, SHE and SYHE, respectively, when compared with the control. The accumulations of nitrogen (N), phosphorus (P) and potassium (K) from panicle initiation to heading were very significantly and positively correlated with the yields. 【Conclusion】 The results indicated that higher grain yield and higher nutrient use efficiency can be coordinately achieved through integrating and optimizing cultivation techniques in rice production.

【目的】旨在探讨水稻高产与养分高效利用协调的栽培技术。【方法】以杂交粳稻常优3号为材料，设置未施氮处理（0N）、当地高产栽培（对照）、增产增效栽培、再高产栽培、再高效栽培和保产增效栽培等6种栽培模式，比较分析不同栽培模式下水稻产量的形成特点和养分吸收利用特征。【结果】增产增效栽培、再高产栽培、再高效栽培和保产增效栽培两年的平均产量分别为9.5、11.5、10.7和9.0 t•hm-2，较对照分别提高了14.5%、38.6%、28.9%和8.4%。与对照相比，上述各处理的氮肥吸收利用率分别提高了39.5%、93.9%、86.1%和31.0%（相对值），氮肥农学利用率分别提高了66.5%、84.4%、98.2%和70.1%。不同栽培模式下水稻穗分化至抽穗期的氮、磷、钾的吸收量与产量呈显著正相关。【结论】通过栽培技术的集成优化，可以大幅度同步提高水稻的产量和养分利用效率。

【Objectives】The objective of this study is to screen and evaluate the nitrogen efficiency of rice cultivars widely grown in South China, and investigate the different phsiology mechanisms between the high and low nitrogen efficient cultivars.【Methods】Thirty four rice cultivars were tested in field trials and pot experiments under both normal and low nitrogen supplies. The high and low nitrogen efficient cultivars were identified by analyzing parameters related to yield and its components, the leaf SPAD value and the aboveground nitrogen accumulation rate of rice. 【Results】 1)Field trials results in 2011 showed that the yields under normal nitrogen treatment were higher than those under low nitrogen treatment for most of the 34 cultivars. Huiliangyou 6, Guangliangyou 35 and Tianyouhuazhan had higher nitrogen efficiencies with 111, 102 and 100, respectively; Xiushui 134, Fudao 2 and Wufengyou 7025 had lower nitrogen efficiencies with 055, 061 and 061, respectively. Similarly, the yield components under the normal nitrogen treatment were higher than those under the low nitrogen treatment for most of the 34 cultivars. The cultivars with higher nitrogen efficiencies have higher panicle number, spikelet number per panicle, as well as thousand grain weight under low nitrogen condition. As a consequence, Huiliangyou 6, Guangliangyou 35 and Tianyouhuazhan were screened as the high nitrogen efficient rice cultivars, and Xiushui 134, Fudao 2 and Wufengyou 7025 as the low nitrogen efficient ones. 2) Field and pot experiments in 2012 showed similar results. Both the actual and theoretical yields and nitrogen efficiencies of Huiliangyou 6 and Guangliangyou 35 are in the high ranking of the tested 34 cultivars, while Xiushui 134, Wufengyou 7025 and Fudao 2 in low ranking. In field trial, both the panicle number and thousand grain weight of high nitrogen efficient cultivar, Guangliangyou 35, were significantly higher than those of low nitrogen efficient ones under normal nitrogen treatment. Under low nitrogen condition, the high N efficient cultivars performed higher or significantly higher SPAD values than the low nitrogen efficient ones. Under normal nitrogen supply in the pot experiment, the SPAD values of the high nitrogen efficient cultivars were slightly higher than the low ones.Under the normal nitrogen condition, there were no significant differences in aboveground N accumulation between the high and low N efficient cultivars at each growth stage, except for Xiushui 134 Under the low N condition, no significant differences at tillering stage, except high N efficient cultivar Huiliangyou 6, in which the N accumulation even lower than N low efficient cultivars. At the heading stage and mature stage, the N accumulation in two high N efficient cultivars were significantly higher than those in low ones. 【Conclusion】Guangliangyou 35 is identified as the highest nitrogen efficient cultivar and Xiushui 134 as the lowest nitrogen efficient cultivar. The high nitrogen efficient cultivar has higher panicle number and spikelet number per panicle under low nitrogen supply condition, which led to the higher yields than the low nitrogen efficient cultivar. Compared with that in the low nitrogen efficient cultivars, the more nitrogen was accumulated in the high nitrogen efficient cultivars at the late growth stage, which enhanced photosynthesis, the carbon and nitrogen assimilation, and then improved yields.

【目的】评价我国南方地区主推水稻品种氮效率，筛选氮高效和氮低效品种，并探索其高效和低效的原因及其生理机制。【方法】选用34份我国南方主推水稻品种，采用大田小区试验和盆栽试验，进行正常氮和低氮处理，利用产量法并结合产量构成因子、叶片SPAD值以及水稻地上部氮素累积量，筛选出氮高效和氮低效品种。【结果】 1）在2011年大田试验中，34个品种正常氮处理产量大多高于低氮处理的产量。通过对氮效率的分析发现，徽两优6号、广两优35和天优华占3个品种具有较高的氮效率，分别达到111、102和100，而秀水134、富稻2号和五丰优7025的氮效率较低，分别为055、061和 061。通过对各品种的产量构成因子分析发现，正常氮处理下，各品种产量构成因子大多高于低氮处理。在低氮条件下，氮高效品种的穗数和穗粒数以及千粒重均较高。通过筛选发现徽两优6号、广两优35和天优华占3个水稻品种表现为氮高效；秀水134、富稻2号和五丰优7025 3个品种表现为氮低效。2）通过2012年大田和盆栽试验的复筛，发现大田与盆栽试验结果基本一致。实际产量和理论产量均表现出徽两优6号和广两优35的产量和氮效率较高，秀水134、五丰优7025和富稻2号的氮效率较低。通过对各品种的产量构成因子分析发现，2012年大田试验中，在正常氮条件下，高效品种广两优35的穗数、千粒重均显著高于低效品种。在对SPAD值的分析中发现，2012年大田试验中，低氮处理下氮高效品种在同一生育时期其SPAD值普遍高于或者显著高于低效品种。2012年盆栽试验中，正常氮处理下，高效品种叶片SPAD值略高于低效品种。在对水稻地上部氮累积量的研究中发现，在正常氮处理下，不同生育期高效品种与低效品种间普遍没有显著性差异，仅低效品种秀水134显著低于其它几个品种；而在低氮处理下，在分蘖期高效品种与低效品种并无显著性差异，甚至高效品种徽两优6号氮素累积量还要低于低效品种；但在灌浆期和成熟期，两个高效品种的氮素累积量高于或显著高于低效品种。【结论】确定广两优35为高效品种，秀水134为低效品种。氮高效品种在低氮胁迫下，能够获得较高的穗数和穗粒数，从而获得较高产量。特别在生育后期，高效品种地上部能够积累更多的氮素，从而可促进光合作用，提高碳、氮同化效率，并获得较高产量。

The difference of root morphological and physiological characteristics of low-yielding and low N-efficiency, high-yielding and medium N-efficiency, high-yielding and high N-efficiency rice cultivars was investigated using six representative japonica varieties under their optimum N levels, respectively. The results showed that the high-yielding genotypes showed distinct advantages over the low-yielding ones in root dry weight, root volume, total and active absorbing surface areas of root system, root oxidation ability of α-NA and root bleeding intensity at each growth stage, indicating that the increase of productivity was accompanied by the improvement of root morphological traits and the enhancement of root physiological activities. Cultivars with different N-efficiency displayed diverse root morphological and physiological characteristics, even though they were all on a high-yielding level. Comparing with medium N-efficiency genotypes, the high N-efficiency ones showed lower root dry weight, root volume, root bleeding intensity and root total absorbing surface area for populations, but for single plants, the root dry weight, root volume, root bleeding intensity, active absorbing surface area and α-NA oxidation amount were superior in a significant or extremely significant degree. The results above suggest that the coordination of high-yielding with high N-efficiency could be achieved through controlling population growth properly, facilitating the concordant development of plant population and individuals, and endeavoring to improve the single stem root quality after heading.

选用低产氮低效型、高产氮中效型和高产氮高效型具有代表性的6个粳稻品种，在各自最适氮素水平下，研究了根系形态生理特征的差异。结果表明，较之低产类型品种，高产类型品种在根干重、根体积、根系总吸收表面积、活跃吸收表面积、根系α-NA氧化量及根系伤流强度等方面在各个生育时期均存在着明显的优势，说明生产力的提高伴随着根系形态特征的改善和生理活性的加强。同为高生产力类型品种，因氮利用率的差异根系形态生理特征表现不同。较之高产氮中效类型，高产氮高效型水稻的群体根干重、群体根体积、群体根系伤流强度和根系总吸收表面积均有所降低，而单茎根干重、单茎根体积、单茎根系伤流强度、活跃吸收表面积比及根系α-NA氧化量却有显著或极显著提高。表明适当控制高生产力水稻的群体生长量，促进群体和个体协调发展，着力提高抽穗后单茎根系质量，将是水稻高产和氮高效协调统一的可靠途径。

The morphological and physiological characteristics of low-yielding and low N-efficiency, high-yielding and medium N-efficiency, high-yielding and high N-efficiency of rice cultivars were investigated using six representative japonica varieties under their respective optimal N application levels. The results showed that compared with low-yielding varieties, high-yielding varieties showed shorter basal 1st internodes, longer basal 6th internodes, increased plant height, larger culm diameter and wall thickness, significantly higher dry weight of stem and sheath, obviously increased K and Si content in culm and sheath, and a higher ratio of Si to N. As a result of their improved stalk physical characteristics and the different chemical compositions, the comprehensive breaking resistance of the culm of high-yielding cultivars was improved evidently, and the lodging index reduced as well. The cultivars with different N-efficiencies displayed diverse culm morphological and physiological characteristics even though they were all in one high-yielding level. Comparing with medium N-efficiency genotypes, the high N-efficiency ones had longer 4th and 5th internode lengths, increased culm wall thickness, in spite of slightly decreased culm diameter, resulted in higher dry weight and strengthened plumpness status of culm, significantly decreased content of Si in stem and sheath, decreased N content, and remarkably unchanged K content. Given these results, for the purpose of further increasing the nitrogen fertilizer use efficiency of the high-yielding varieties, it would be favorable to properly increase 4th and 5th internode length, thus improving top three leaves configuration, to appropriately reduce the culm diameter while increasing wall thickness and filling degree for the sake of stalk breaking resistance and transporting capability, and to properly reduce the content of Si in culm and sheath to facilitate the translocation of nitrogen.

选用低产氮低效型、高产氮中效型和高产氮高效型具有代表性的6个粳稻品种，在各基因型各自最适氮素水平下，研究了茎秆力学特性、物理特性和化学成分含量的差异及其与氮效率的关系。结果表明：(1)较之低产类型品种，高产类型品种茎秆基部N 1 节间变短、N 6 节间变长，株高有所增加；茎粗、茎壁厚、茎鞘干重均极显著增加；茎鞘的K、Si含量极显著增加，N含量显著降低。由于茎秆物理性状的改善及化学成分的差异导致茎秆综合抗折力明显提高，倒伏指数降低。(2)同为高生产力类型品种，因氮效率的差异茎秆形态生理特征表现不同。较之高产氮中效类型，高产氮高效类型水稻品种茎秆N 4 、N 5 节间变长；茎秆粗度略有降低，但茎壁厚增加，表现茎秆干重增加，充实度加强；茎鞘的K含量无明显变化，但Si含量显著降低，N含量也呈降低趋势。对于高产品种，适当增加N 4 、N 5 节间长度以改善叶片配置，适当降低茎粗而提高壁厚和充实度以保证茎秆抗折力和输导能力，适当降低茎鞘Si含量以促进氮素的转移，有利于进一步提高氮肥利用率。

Roots are an integral part of plant organs and involved in acquisition of nutrients and water, synthesis of plant hormones, organic acids and amino acids, and anchorage of plants. Root morphology and physiology are closely associated with the growth and development of above-ground part of plant. In this review, the relationships of root morpho-physiological traits with the formation of grain yield and the absorbtion of water and nutrients in rice were summerized. Recent advances in research on the role of the root chemical signals, such as hormones and organic acids, in the formation of grain quality of rice and the relation of ultra-structure of root tip cells with the growth and development of above-ground part of plant were intruduced. The existing problems and futher studies on rice roots were discussed.

植物根系既是水分和养分吸收的主要器官,又是多种激素、有机酸和氨基酸合成的重要场所,其形态和生理特性与地上部的生长发育有密切联系。本文综述了水稻根系形态生理与产量形成及水分养分吸收利用的关系,介绍了根系化学信号(激素、有机酸等)对稻米品质形成的作用及根尖细胞超微结构与地上部生长发育关系的最新研究进展,讨论了水稻根系研究存在的问题和今后研究的重点。

The difference of dry matter production and translocation characteristics in low-yielding and low N-efficiency, high-yielding and medium N-efficiency, high-yielding and high N-efficiency rice cultivars was investigated using six representative japonica varieties under their optimum N supply levels, respectively. The results indicated that: with the increase of rice productivity, the total dry matter production amount significantly increased by 20.29% on average, and the dry matter accumulation amount and population growth rate increased on average by 15.05%, 27.04%, 24.75% and 15.05%, 28.38%, 23.00%, during the period before N-n (critical stage of productive tillering) , from jointing to heading, and from heading to maturing, respectively, and decreased during the period from N-n to the jointing. Among the high-yielding varieties, with the nitrogen use efficiency increased, the tiller number per unit area at each growth stage showed a downward trend, and significantly reduced on average by 5.76%, 11.61%, 7.01%, and 5.70% at N-n, jointing, heading and maturing, respectively, but ratio of productive tillers to total tillers significantly increased. At each growth stage, the dry matter accumulation amount showed a declined tendency, and reduced on average by 12.18%, 10.54%, 8.29%, and 5.01% at N-n, jointing, heading and maturity, respectively, but harvest index significantly increased. During the period from heading to maturing, dry matter accumulation rate increased on average by 5.40%, the population growth rate increased on average by 5.19%. The results above showed that proper control for population growth before heading, maintaining a high growth rate after heading and a higher harvest index were the important dry matter accumulation characteristics of the cultivars with high-yielding and high nitrogen use efficiency.

选用低产氮低效型、高产氮中效型和高产氮高效型具有代表性的 6 个粳稻品种，在各自最适氮素水平下，研究了干物质积累与转运特性的差异及其与氮效率的关系。结果表明，较之低产类型品种，高产类型品种物质生产总量提高 20.29% ，差异达显著水平。其中在够苗前、拔节至抽穗、抽穗至成熟阶段的干物质积累量和群体生长率分别提高 15.05% 、 27.04% 、 24.75% 和 15.05% 、 28.38% 、 23.00% ，够苗至拔节阶段则互有高低。同为高产类型品种，因氮利用率的差异物质积累与转运特性不同。较之高产氮中效型，高产氮高效型品种各生育时期的单位面积茎蘖数均呈下降趋势，其中够苗、拔节、抽穗和成熟期平均分别降低 5.76% 、 11.61% 、 7.01% 和 5.70% ，差异均达显著水平，而成穗率显著提高。各生育时期的干物质积累量均有所下降，其中，够苗、拔节、抽穗和成熟期分别降低 12.18% 、 10.54% 、 8.29% 和 5.01% ，收获指数却显著提高。抽穗至成熟阶段的干物质积累率提高 5.40% ，群体生长率提高 5.19% 。说明抽穗前适当控制群体生长，抽穗后保持较高的群体生长水平及较高的收获指数是高产氮高效型品种的重要物质生产特性。

The leaf carbon and nitrogen metabolism characteristics and their relationships with  nitrogen utilization efficiency(NUE) at  jointing stage were investigated with Xiuhui 2 (low NUE), R8312 (medium NUE) and Wuyou 244 (high NUE) as materials  under the lower nitrogen level (58 mg/kg). The results showed that the contents of sucrose and soluble sugar  in the leaves of different rice genotypes    were Wuyou 244 > R8312 > Xiuhui 2, the ratio  of starch content to soluble sugar content and  the ratio of starch  content to sucrose  content  were Xiuhui 2>R8312>Wuyou 244, significantily differed among genotypes. The  starch content and the  ratio of sucrose content to soluble sugar content were not genotypically specific. The  total nitrogen content (TNC), protein nitrogen content (PNC), PNC/TNC, RC(Rubisco content)/PNC  and RC/TNC in the leaves of different rice genotypes exhibited significant differences,  showing an increasing trend of Wuyou 244 R8312>Wuyou 244 for the latter  three; RC was not genotypicallyspecific. The contents of chlorophyll and carotenoid, activity of PSⅡ, carboxylation efficiency, activities of carbonic anhydrase, acid invertase and sucrose phosphate synthase in the leaves of Wuyou 244 with high NUE were significantly higher than those of the other genotypes. The activities of nitrate reductase, glutamine synthetase and glutamate synthase and glutamate dehydrogenase in the leaves of Wuyou 244 with high NUE were also significantly higher than those of the other genotypes. Statistical analyses indicated that the leaves of rice genotype with high NUE had the distinguished characteristics of higher soluble sugar content, sucrose content, RC/TNC and RC/PNC, their physiological base were higher   glutamine synthetase activity and primary PSⅡ activity.

采用土培盆栽试验，以3个氮素利用效率(NUE)有显著差异的水稻基因型秀恢2号(低NUE)、R8312(中NUE)和五优244(高NUE)为材料，研究了拔节期叶片碳氮代谢的基因型差异及其与氮素高效利用的关系。结果表明，拔节期不同基因型水稻的叶片蔗糖和可溶性糖含量、淀粉/可溶性糖含量比和淀粉/蔗糖含量比存在极显著差异，前两者为五优244 > R8312 >秀恢2号，后两者则相反；而淀粉和蔗糖/可溶性糖含量比各基因型差异不显著。不同基因型水稻的叶片全氮含量(TNC)、蛋白氮含量(PNC)、 PNC/TNC、Rubisco含量(RC)/PNC和RC/TNC存在极显著或显著差异，前两者为五优244 < R8312 <秀恢2号， 后三者则相反；RC无基因型差异。五优244叶片的叶绿素a含量、类胡萝卜素含量、PSⅡ潜在活性、羧化效率、碳酸酐酶、酸性转化酶和蔗糖磷酸合成酶活性极显著或显著高于其他基因型；其叶片的硝酸还原酶、谷氨酰胺合成酶、谷氨酸合成酶和谷氨酸脱氢酶活性也极显著高于其他基因型。统计分析表明，高NUE水稻叶片具有较高的可溶性糖和蔗糖含量及较大的RC/TNC和RC/PNC，其生理基础是其叶片的高谷氨酰胺合成酶活性和PSⅡ潜在活性。

To investigate the effect of nitrogen management practices on root traits, the amount of nitrogen absorption at grain maturity, nitrogen fertilizer use efficiency, and to analysis the main root traits of rice responsible for high nitrogen absorption efficiency, a total of 15 conventional Indica rice varieties with marked differences in nitrogen absorption efficiency were pot-cultured in 2011 and 2012. (1) The amount of nitrogen absorption (ANA) at grain maturity was differed significantly among rice varieties and nitrogen fertilizer treatments. Among varieties, nitrogen absorption efficiency was positively correlated with ANA at grain maturity in all nitrogen treatments. In rice varieties with high nitrogen absorption efficiency ANA was greater than that in rice varieties with intermediate and low nitrogen absorption efficiency. In rice varieties with high nitrogen efficiency ANA was increased by increasing nitrogen fertilizer application rates or by using the base+ promoting-spikelet fertilizer treatment. (2) Rice varieties with high nitrogen absorption efficiency showed higher adventitious root numbers, root dry weight, total adventitious root length, and also had relative higher root activity at conventional and high rates of nitrogen supply. Rice varieties with high nitrogen absorption efficiency had higher adventitious root numbers, total adventitious root length, root dry weight, root total absorption area and active absorption, as well as crown:root ratio. Increasing the nitrogen application rate increased total adventitious root length and root activity. The appropriate rate of nitrogen application increased adventitious root number and root dry weight. Nitrogen application at the early growth stage promoted the occurrence and extension of adventitious roots, while at the late growth stage nitrogen addition enriched adventitious roots and improved root physiological activity. In addition, increased nitrogen supply improved the crown:root ratio of rice varieties with different nitrogen absorption efficiencies. (3) Rice varieties with high nitrogen absorption efficiencies had higher nitrogen absorption and use efficiencies than those with middle and low nitrogen absorption efficiencies at the conventional and high rates of nitrogen supply. (4) Increasing adventitious root number, total adventitious root length, root activity and crown:root ratio at heading stage improved ANA in all rice varieties. Increasing root dry weight also had a significant and positive effect on ANA in all rice. Correlation analysis and path analysis indicated that crown:root ratio at heading stage, adventitious roots number, root activity, total adventitious root length and adventitious root dry weight were the main root traits that affected nitrogen absorption in the rice varieties with high nitrogen absorption efficiencies.

2011-2012年在土培条件下,以氮素吸收效率差异较大的15个常规籼稻为供试材料,研究氮肥运筹对不同氮效率品种根系性状、成熟期吸氮量及氮肥利用率的影响,分析影响氮高效水稻氮素吸收的主要根系性状。结果表明:(1)各氮肥处理下,成熟期吸氮量均表现为氮高效品种 > 氮中效品种 > 氮低效品种。适量增施氮肥及基肥+促花肥处理有利于氮高效品种吸氮量的增加,氮素吸收受品种、氮肥处理的显著影响。(2)在施氮量处理下,氮高效品种单株不定根数、单株根干重、单株不定根总长大或较大,单株根活力在常氮(N2)、高氮(N3)处理下有一定的优势;在施氮时期处理下,氮高效品种单株不定根数、单株不定根总长、单株根干重、单株根系总吸收面积、单株根系活跃吸收面积、抽穗期冠根比多数处理有优势;增施氮肥有利于促进氮高效品种单株不定根总长和单株根活力的提高,适量施氮有利于单株不定根数、单株根干重增加,前期施氮可促进不定根的发生和伸长,后期施氮有利于不定根的充实和根系生理性状的提高。此外,增施氮肥可提高各类品种冠根比;(3)在常氮、高氮处理下,氮高效品种氮肥利用率大于氮中效、氮低效品种。(4)提高单株不定根数、单株不定根总长、单株根活力及抽穗期冠根比有利于各类品种吸氮量的提高,增加根干重对氮高效品种吸氮量的提高也有显著的促进作用。结合相关分析与通径分析结果,抽穗期冠根比及单株不定根数、单株根活力、单株不定根总长、单株根干重是影响氮高效品种吸氮能力的主要根系性状。

The optimal water-nitrogen (N) managements and the selection of genotypes with high nitrogen utilization efficiency (NUE) play a vital note in rice production aiming at high yield, high NUE and water-saving irrigation. In order to elucidate effects of water-nitrogen management patterns on N utilization characteristics, grain yield and its physiological basis in rice cultivars with different NUEs. Two different NUE rice cultivars with high-yield and high N-efficiency (Dexiang 4103) as well as medium-yield and low N-efficiency (Yixiang 3724), were used with three water-nitrogen management patterns, including standing irrigation and optimized N application (W1N1), alternate irrigation and optimized N application (W2N1), and dry cultivation and optimized N application (W3N2). The relationship between yield or N utilization characteristics and glutamine synthetase (GS) activity, photosynthetic rate ( P n ) and root activity was investigated. The results showed that rice cultivars with different NUEs and water-nitrogen management patterns significantly affected N utilization characteristics, irrigation water use efficiency, physiological characteristics and grain yield. The regulation effects of water-nitrogen management patterns on NUE indexes (physiological efficiency, agronomy efficiency, and N recovery efficiency) were lower than those of rice cultivars with different NUEs, while the effects of water-nitrogen management on irrigation water use efficiency, total N accumulation, N dry matter production efficiency, and N production efficiency were significant. Compared with W1N1 and W3N2, W2N1 could promote the N uptake from elongation to maturing stages, enhance activity of GS, P n , and root activity, and then improve grain yield and NUE of two different NUE rice cultivars, being the best model in this experiment. Moreover, the regulation effects of water-nitrogen management patterns on the cultivar with medium-yield and low N-efficiency were significantly higher than these with high-yield and high N-efficiency rice cultivars. The results also showed that average total spikelet number, N accumulation from elongation to heading stages, GS activity and P n of leaves, and root activity of high N-efficiency rice cultivar were higher than those of low N-efficiency rice cultivar . Especially, during filling stage compared with medium-yielding and low N-efficiency cultivar, the high-yielding and high N-efficiency rice cultivar was more beneficial to higher metabolism and assimilation capacity of leaves and roots, which is the important reason for high-yielding and high N-efficiency rice cultivar further to increase yield and NUE. Correlation analysis indicated that there existed significantly positive correlations of GS activity and P n of leaves, and root activity in the two N-efficiency rice cultivars with indices of N uptake and utilization and yield, furthermore, the maximum correlation coefficients of GS activity of leaves and root activity with yield or NUE were observed at heading stage.

以高产氮高效品种(德香4103)和中产氮低效品种(宜香3724)为材料，通过“淹水灌溉+氮肥优化运筹(W1N1)”、“控制性交替灌溉+氮肥优化运筹(W2N1)”、“旱种+氮肥优化运筹(W3N2)” 3种水氮管理模式处理，研究其对氮素利用及产量的影响及其生理特性，并探讨氮素利用及产量与生理响应间的关系。结果表明，氮效率品种间的差异与水氮管理模式对水稻氮素利用特征、灌溉水生产效率、生理特性及产量均存在显著影响；不同氮效率品种间在氮肥利用效率方面的差异明显高于水氮管理模式的调控效应；而水氮管理模式对灌溉水生产效率、总吸氮量、氮素干物质生产效率及稻谷生产效率的调控作用显著。W2N1相对于W1N1及W3N2水氮管理模式能促进不同氮效率水稻拔节至抽穗期、抽穗至成熟期氮素的累积，提高功能叶谷氨酰胺合成酶(GS)活性、光合速率( P n )及根系活力，进而提高稻谷产量及氮肥利用率，且对中产氮低效品种的调控效应显著高于对 高产氮高效品种，为本试验最佳的水氮管理模式。高产氮高效品种的平均总颖花数、拔节至抽穗期稻株氮累积量、功能叶 GS活性、 P n 及根系活力均显著高于氮低效品种，尤其结实期高产氮高效品种更有利于维持叶片及根系的代谢同化能力，利于氮素转运、再分配到籽粒中提高稻谷生产效率及氮肥利用效率，是氮高效品种相对于氮低效品种高产、氮高效利用的重要原因。相关分析表明，水氮管理模式下不同氮效率水稻主要生育时期功能叶GS活性、 P n 及根系活力与氮素利用及稻谷产量均存在显著或极显著的正相关；尤其以水稻抽穗期剑叶GS活性及根系活力与氮素利用及稻谷产量的正相关性最高。

介绍了中国水稻生产氮肥使用及利用率概况。中国氮肥消费量占世界氮肥总量的 30 %,水稻生产所消耗的氮肥占世界水稻氮肥总消耗量的 37%。与主要产稻国相比 ,中国水稻生产氮肥施用量较高而利用率较低 ;介绍了国际上公认的氮肥利用率的概念和相应的定量方法 ;总结了国内外水稻氮肥的施用方法 ,肥料种类 ,计算机推荐施肥以及实时施氮管理模式等对降低氮素损失 ,提高氮肥利用率的研究概况和研究进展 ;从水稻品种耐肥性、土壤供肥能力、施肥技术及水分管理等多方面分析了中国水稻氮肥利用率低的可能原因 ;提出了通过改善水稻品种对氮肥的敏感反应 ,以作物氮素状况为指导适时和适量施用氮肥 ,以及合理调节土壤背景氮来降低氮素损失 ,提高水稻的氮肥利用率的研究策略。

Three standard indica test varieties,three standard japonica test varieties and other thirteen rice accessions,which are Yongyou series hybrid rice combinations and their parents,were analyzed by using 22 simple sequence repeat(SSR)primer pairs.Totally 87 alleles were detected.These primers revealed polymorphism with a range of 2-8 alleles per primer pair.Fingerprintings of Yongyou series hybrid rice combinations and their parents were set up.The cluster analysis showed that the tested materials were grouped into two clusters in accordance with the indica/japonica classification based on the Cheng’s index.It was confirmed that Yongyou 4 and Yongyou 6 are inter-subspecific hybrid rice combinations between indica and japonica at molecular levels.

用22个SSR分子标记对13份甬优系列杂交水稻组合及其亲本材料和6份籼粳对照种进行分析，共获得87个等位基因，每对引物扩增的等位基因数为2~8个。所有供试材料间均检测到了差异，从而建立起甬优1号~甬优6号杂交水稻组合及其亲本的DNA指纹图谱。聚类分析结果表明，9份供试材料与3份粳稻对照种聚于一类，属粳稻；4份供试材料与籼稻对照种IR36聚于一类，属籼稻。这与形态分类结果基本一致。从分子水平确认了杂交水稻甬优6号和甬优4号为籼粳亚种间杂交稻。

Using indica-japonica super rice Yongyou 12, by transplanting seedlings with tillers at the age of four leaves with one leaf bud and applying super sparse cultivation technology, we compared and studied grain yield and its components, tiller dynamic, leaf area dynamic and accumulation dynamic of dry matter in three types of populations (High yield: 10.5–12.0 t ha -1 ; Higher yield: 12.0–13.5 t ha -1 ; Super-high yield: >13.5 t ha -1 ). The results showed that super-high yielding rice had more population spikelets, and slightly lower seed-setting rate and 1000-grain weight than high yielding and higher yielding rice. Compared with high yielding and higher yielding rice, super-high yielding rice showed more number of stems and tillers at transplanting stage and achieved the expected number of stems and tillers at the critical leaf-age for productive tillers. During jointing stage the number of stems and tillers increased steadily and up to the maximum with a panicle rate of nearly 60%. The leaf area index of super-high yielding rice was relatively smaller at the early stage and the maximum of 9.17 at booting stage, and then slowly declined to more than 4.0 at maturity; The dry matter weight was relatively smaller at jointing stage and then the highest at each phase of the super-high yielding rice, which was 14.38 t ha -1 at heading stage, 9.73 t ha -1 from heading to maturity stage, and 24.11 t ha -1 at maturity stage. The root dry weight, ratio of root to shoot and root bleeding intensity per stem of the super-high yielding rice population were all the highest from heading to maturity stages.

以籼粳交超级稻甬优12为试材、四叶一心期带蘖小苗移栽，超稀植(12.45×104穴 hm -2 )栽培，对高产(10.5~12.0 t hm -2 )、更高产(12.0~13.5 t hm -2 )、超高产(>13.5 t hm -2 ) 3个产量群体的产量及其结构、茎蘖动态、叶面积动态及干物质的积累与运转等进行了系统比较研究。结果表明，产量由高产(10.5~12.0 t hm -2 )到更高产(12.0~13.5 t hm -2 )再到超高产(>13.5 t hm -2 )，群体的颖花量不断提高，结实率和千粒重略微下降。与高产和更高产群体相比，超高产群体茎蘖数起点较高，在有效分蘖临界叶龄期及时够苗，至拔节期群体茎蘖数稳步增长，达高峰苗，此后群体茎蘖数平缓下降，成穗率近60%；群体叶面积指数生育前期较小，最大值出现在孕穗期，为9.17，此后平缓下降，成熟期在4.0以上；群体干物质积累量在拔节期略低，此后各生育时期均升高，抽穗期为14.38 t hm -2 ，抽穗至成熟期为9.73 t hm -2 ，成熟期为24.11 t hm -2 ；群体根系干重、根冠比及单茎伤流强度在后期(抽穗至成熟期)均较高。

In order to determine the absorption and accumulation of phosphorus (P) in super high yielding rice population of Yongyou 12, the field experiments were conducted with these populations of high yield (HY, 10.5–12.0 t ha -1 ), higher yield (HRY, 12.0–13.5 t ha -1 ), and super high yield (SHY, >13.5 t ha -1 ) in 2013 and 2014. Results indicated that there was no significant difference in P content of plant at each growth stage among three yield groups. HY showed the highest P plant uptake while SHY the lowest at jointing among three yield groups. Opposite trends were observed at heading and maturity stages. There existed a significant ( P P -1 , respectively for SHY, higher than thosefor HRY (37.9, 7.6, 8.1 kg ha -1 ) and HY (32.3, 6.8, 7.0 kg ha -1 ). There existed significant ( P -1 , respectively, higher than those of HRY (13.6, 3.3, 55.9 kg ha -1 ) and HY (11.2, 2.7, 48.7 kg ha -1 ). There existed significant and positive linear correlation of grain yield with P accumulation in the stem and sheath, leaf, and panicle at maturity and with P translocation from stem and sheath to grain after heading. When values were averaged across two years,internal nutrient efficiency (kg grain kg -1 ) and partial factor productivity (kg kg -1 ) of SHY were 171.5 and 92.7, respectively, less than those of HRY (173.2, 99.6) and HY (173.5, 100.4). Harvest index of P of SHY was 0.768, significantly higher than that of HRY (0.761) and HY (0.758). SHY showed lower P accumulation before jointing, while higher P accumulation from jointing to heading, and from heading to maturity, when compared with check. There existed significant ( P P

为探明甬优12超高产群体的磷素吸收与积累特征，2013—2014年，对 高产 (10.5~12.0 t hm -2 )、更高产(12.0~13.5 t hm -2 )、超高产(>13.5 t hm -2 )3个产量群体的磷素吸收与积累特征等进行了系统比较研究。结果表明：(1)生育期植株含磷量，不同产量水平群体间无显著差异；拔节期磷素吸收量呈高产群体>更高产群体>超高产群体；而抽穗期和成熟期磷素吸收量则呈超高产群体>更高产群体>高产群体。播种至拔节期的磷素积累量与产量呈极显著负相关；拔节至抽穗期、抽穗至成熟期的磷素积累量与产量呈极显著正相关。(2)甬优12超高产群体抽穗期茎鞘、叶片和穗部磷素积累量分别为41.4、8.5和8.9 kg hm -2 ，高于更高产群体(37.9、7.6和8.1 kg hm -2 )和高产群体(32.3、6.8和7.0 kg hm -2 )。抽穗期植株叶片、茎鞘和穗部磷素积累量与产量呈极显著正相关；甬优12超高产群体成熟期茎鞘、叶片和穗部磷素积累量分别为14.5、4.4和62.3 kg hm -2 ，高于更高产群体(13.6、3.3和55.9 kg hm -2 )和高产群体(11.2、2.7和48.7 kg hm -2 )。成熟期植株叶片、茎鞘和穗部磷素积累量与实产呈极显著正相关。此外，花后茎鞘磷素转运量亦与产量呈极显著正相关。(3)两年中，甬优12超高产群体磷素籽粒生产率(kg grain kg -1 )和偏生产力(kg kg -1 )分别为171.5、92.7，低于更高产(173.2、99.6)和高产群体(173.5、100.4)；超高产群体磷收获指数为0.768，显著高于更高产(0.761)和高产(0.758)群体。与对照相比，甬优12超高产群体磷素吸收具有拔节前较低、拔节至抽穗期和抽穗至成熟期高的特点。播种至拔节期磷素积累量与产量呈极显著负相关；拔节至抽穗期、抽穗至成熟期磷素积累量与产量呈极显著正相关。甬优12超高产群体磷素利用效率较低，在其超高产栽培管理中应重视磷素的高效利用。在本研究基础上探讨了提高甬优12超高产群体磷素利用效率的措施。

A field experiment was conducted using the representative varieties of four types ( indica/japonica hybrid rice, inbred japonica rice, hybrid japonica rice, and hybrid indica rice) to achieve the highest rice yield for each variety that is defined as the highest population productivity of N fertilization at six nitrogen fertilization levels (0, 187.5, 225 .0 , 262.5, 300.0, and 337.5 kg ha -1 ). On this basis, the differences in yield components, duration of main growth stages, dry matter weight, and leaf area index at main growth stages for four types were studied. The results were as follows: (1) The highest grain yield   rice was achieved under 225 .0 –262.5 kg ha -1 nitrogen application for hybrid indica , 300 kg ha -1 for inbred japonica rice, 262.5–300.0 kg ha -1 for hybrid japonica rice and 262.5–300.0 kg ha -1 for indica / japonica hybrid rice. (2) The population productivity of indica/japonica hybrid rice was the highest, followed by hybrid japonica rice, inbred japonica rice, and hybrid indica rice. Indica/japonica hybrid rice had more spikelets and spikelets per panicle, but great fluctuation was observed in number of spikelets per panicle across two years. Inbred japonica rice had more panicles and higher seed-setting rate while hybrid japonica rice had the highest 1000-grain yield weight. (3) The longest duration from sowing to heading stages was observed for hybrid japonica rice. The duration from heading to maturity of indica/japonica hybrid rice was about 60 d, which was significantly higher than that of other three variety types. Grain yield per day of japonica/indica hybrids was the highest among the four variety types in two years. (4) The dry matter weight and leaf area index at heading, 20 d after heading, and maturity stage of indica/japonica hybrid rice were higher higher than thoes of other three variety types. As for dry matter accumulation, indica/japonica hybrid rice was the highest from heading to maturity stage. Moreover, the leaf area duration from jointing to heading and from heading to maturity in indica/japonica hybrid rice was also higher than that of other three variety types. Great yield of japonica/indica hybrids of Yongyou series over other three variety types is mainly attributed to more spikelets per panicle, longer filling phase, higher grain yield per day and biomass production after heading.

以长江下游地区大面积种植的4种类型(籼粳杂交稻、常规粳稻、杂交粳稻和杂交籼稻)水稻品种中有代表性的品种为材料, 设置6个氮肥水平(0、187.5、225.0、262.5、300.0、337.5 kg hm -2 ),比较研究其氮肥群体最高生产力及其产量构成、关键生育阶段天数、主要生育时期的叶面积指数和干物重。结果表明: (1)杂交籼稻获得最高生产力对应的施氮量为225.0~262.5 kg hm -2 , 常规粳稻为300.0 kg hm -2 , 杂交粳稻和籼粳杂交稻为262.5~300 kg hm -2 。(2)氮肥群体最高生产力以籼粳杂交稻最高, 达12.2 (12.0~12.3) t hm -2 ,较杂交粳稻、常规粳稻和杂交籼稻分别高出6.6%、9.8%和19.6% (两年平均值)。群体颖花量和每穗粒数均以籼粳杂交稻最高, 但其每穗粒数年度间波动较大。穗数和结实率以常规粳稻最高。(3)播种至抽穗期天数以杂交粳稻最长, 抽穗至成熟期天数则以籼粳杂交稻最长, 达60 d左右。全生育期天数呈杂交粳稻>常规粳稻>籼粳杂交稻>杂交籼稻。两年中日产量以籼粳杂交稻最高。(4) 籼粳杂交稻在抽穗、抽穗后20 d和成熟期的叶面积指数和干物重均显著高于另外3种类型品种, 且抽穗至成熟期的干物质积累量也最高。此外, 籼粳杂交稻在拔节至抽穗期以及抽穗至成熟期的光合势显著高于另外3种类型品种。较多的每穗粒数、较长的灌浆期天数以及较高的日产量、生育后期(抽穗至成熟期)较强的光合物质生产能力是籼粳杂交稻氮肥群体最高生产力形成的重要原因和基础。

A field experiment was conducted using indica/japonica hybrid super rice Yongyou 538 as the material, conventional japonica rice Zhendao 18 and hybrid indica rice Zhongzheyou 1 as the check to study the characteristics of nitrogen accumulation after heading and compare the differences in characteristics of nitrogen accumulation after heading in different types of rice variety. Results followed that, on an average across two years, grain yield of Yongyou 538 was 12.5 t ha -1 , significantly higher than that of check varieties. Nitrogen accumulation at heading, at maturity, and from heading to maturity showed a trend of Yongyou 538>Zhendao 18>Zhongzheyou 1. Nitrogen absorption of 100 kg seeds of Zhendao 18 was the highest, followed by Zhongzheyou 1, and Yongyou 538, while opposite trends was observed for N partial factor productivity. Compared with the check, nitrogen output from stem and nitrogen increase in panicle of Yongyou 538 were consistently higher. Nitrogen accumulation in Yongyou 538 and Zhendao18 was both higher than that of Zhongzheyou 1 after heading, and Richards' equation was fit to simulate the relationship between nitrogen accumulation and days after heading for three types of rice variety ( R 2 ≥0.995). Maximum rate of nitrogen accumulation, mean rate of nitrogen accumulation, and days to maximum rate of nitrogen accumulation after heading in Zhendao 18 were the highest, while those in Yongyou 538 were the lowest. Effective nitrogen accumulation duration showed a trend of Yongyou 538> Zhendao 18>Zhongzheyou 1. Duration days, nitrogen accumulation rate, and nitrogen accumulation in early and late stage of Zhendao 18 were the highest, while those of Yongyou 538 were the lowest. Duration days and nitrogen accumulation in middle stage of Yongyou 538 was consistently higher compared with the check. Our results indicated that greater nitrogen uptake of Yongyou 538 was mainly occurred in the middle stage, which was 86.1% of the nitrogen accumulation from heading to maturity. And higher nitrogen uptake in middle stage after heading of Yongyou 538 was mainly attributed to the longer duration days in this stage.

以甬优籼粳交超级稻甬优538为试材，常规粳稻镇稻18和杂交籼稻中浙优1号为对照，研究甬优籼粳杂交稻花后氮素积累特征以及比较不同类型品种花后氮素积累特征差异。结果表明: (1)两年中，甬优538平均产量为12.5 t hm -2 ，显著高于对照。抽穗期、成熟期及抽穗-成熟期氮素积累量均呈甬优538>镇稻18>中浙优1号。百千克籽粒吸氮量以镇稻18最高，甬优538最低；氮肥偏生产力则以甬优538最高，镇稻18最低。甬优538花后茎鞘氮素转运量和转运率、穗部氮素积累量显著高于对照。(2)镇稻18和甬优538花后各时期氮素积累量均高于中浙优1号，且各品种花后氮素积累量与花后天数均以Richards方程拟合效果较好( R 2 均大于0.995)。分析特征参数，花后最大氮素积累速率、花后平均氮素积累速率及花后到达最大氮素积累速率的时间均呈镇稻18>中浙优1号>甬优538，花后氮素有效吸收时间则呈甬优538>镇稻18>中浙优1号。花后氮素积累渐增期、缓增期的持续天数、积累速率和积累量以镇稻18最高、甬优538最低，快增期的持续天数和积累量以甬优538显著高于对照。本研究结果表明，甬优538花后较强的氮素积累优势集中在快增期，此期氮素积累量占其花后氮素积累总量的86.1%(两年平均值)。且甬优538在花后快增期较强的氮素积累能力主要在于其较长的快增期持续天数。

【Objectives】A systematic analysis on the rice yield, component factors, nutrient absorption, translocation, nitrogen use efficiency and nitrogen balance in soil under different nitrogen levels was performed to provide theoretical basis for rational amount of applied nitrogen in rice field in northeast China, and the interactions relationship between nitrogen, phosphorus and potassium in soil as well as relationships between nutrient and yield were discussed.【Methods】The field experiment was carried out by using local major rice varieties (Fuyou 135 and Jijing 511) at Hongguang State Farm of Qianguo County in Songyuan City of Jilin province from 2012 to 2013, and the experiment includes five treatments with different nitrogen levels (0, 60, 120, 180and 240 kg/hm 2 ). As plant samples, stem-sheath, leaf and grain parts at returning green stage, mid-tillering stage, heading stage, filling stage and maturity stage were collected to measure the contents of nitrogen, phosphorus and potassium, respectively. Based on these data, the nutrient absorption, translocation, nitrogen use characteristics parameters, and the relationships between nutrient absorption, translocation and yields of the plant at the main growth stages of rice were calculated or evaluated. The soil samples from 0-100 cm soil depth (each layer 20 cm) were respectively collected before transplanting and after harvest of rice to measure the contents of ammonium and nitrate nitrogen. Depending on the soil bulk density of each layer, the amount of inorganic nitrogen accumulation in 0-100 cm soil layer was calculated to profile soil nitrogen balance.【Results】Data showed that when the amounts of applied N were ranged from 60 kg/hm 2 to 180 kg/hm 2 , the rice yield increased with increasing amounts of nitrogen fertilizer, and decreased when the amount of applied N was over N 180 kg/hm 2 . Based on the prices factors of rice and fertilizers in the past years, N rates for obtaining maximum yield were 212.8 kg/hm 2 and 220.6 kg/hm 2 respectively, and the range of nitrogen application was ranged from 202.2 kg/hm 2 to 231.6 kg/hm 2 . N rates for getting the optimum yield were 203.0 kg/hm 2 and 209.1 kg/hm 2 , and the range of nitrogen application was determine to be between192.9 kg/hm 2 and 219.6 kg/hm 2 by simulating between rice yield (y) and nitrogen fertilizer application (x), respectively. Nitrogen fertilizer application could significantly improve the accumulation of nitrogen, phosphorus and potassium at main growing stages, and increased the translocation of nitrogen, phosphorus and potassium to grains at heading stage. The accumulation amount of nutrients at heading stage is proportional to the amount of translocation to grain under N 180 kg/hm 2 . Nitrogen fertilizer rates over 180 kg/hm 2 had negative effects on the translocation of nitrogen, phosphorus and potassium to grain. Nitrogen agronomic efficiency and partial factor productivity were significantly decreased because of increasing nitrogen fertilizer application. The highest nitrogen recovery efficiency in current season was in the treatment of N 180 kg/hm 2 . Correlation analysis showed that the yield had significantly or extremely significantly positive correlations with absorption and translocation of nitrogen, phosphorus and potassium at the main growth periods of rice, and the highest correlation coefficient was exhibited at the filling stage. Nitrogen fertilizer application could significantly improve residual Nmin at 0-100 cm soil after harvesting, and increase in nitrogen fertilizer application apparently enhanced the losses of N.【Conclusions】Optimum nitrogen fertilizer application could significantly improve rice yield, the total nutrient accumulation at different growing stages, the translocation amount of nitrogen, phosphorus and potassium from straw to grain during the late growth period of rice, and apparently reduce losses of soil N. Comprehensively, considering on the rice yield, benefit, nitrogen recovery efficiency in season and nitrogen balance in soil, the optimum nitrogen application rate was determined to be ranged from 192.9 kg/hm 2 to 219.6 kg/hm 2 in this experiment.

【目的】为解决东北地区水稻合理施用氮肥问题,系统研究了不同施氮水平条件下,东北水稻产量及构成因素、养分吸收、转运、氮肥利用效率及土壤氮素平衡的变化,并探讨各养分间及其与产量间的关系,为东北地区水稻合理施氮提供理论基础。【方法】于2012～2013年在吉林省松原市前郭县红光农场,选用当地主栽水稻品种富优135和吉粳511为材料,设置施N 0、60、120、180和240 kg/hm 2 5个水平。于水稻返青期、分蘖期、抽穗期、灌浆期及成熟期采集植株样本,分为茎鞘、叶片和籽粒三部分,测定氮、磷、钾含量,计算水稻主要生育期植株养分吸收、转运、氮素利用特性的相关参数及各养分吸收、转运与产量间的关系。水稻移栽前和收获后采集0—100 cm土壤样品,每20 cm为一层(共5层),测定铵态氮、硝态氮含量,并根据各层土壤容重计算0—100 cm土体无机氮积累量,分析土壤氮素平衡状况。【结果】 施氮量60～180 kg/hm 2 范围内,水稻产量随着施氮水平的提高而增加,氮肥用量超过180 kg/hm 2 水稻产量下降。结合当年水稻和肥料价格,根据水稻产量(y)和施氮量(x)拟合方程,得出最高产量氮肥用量分别为212.8 kg/hm 2 和220.6 kg/hm 2 ,施氮范围在202.2～231.6 kg/hm 2 之间,最佳经济产量氮肥用量分别为203.0和209.1 kg/hm 2 ,施氮范围在192.9～219.6 kg/hm 2 之间。施用氮肥可显著提高水稻主要生育期氮、磷、钾吸收量,且能提高水稻抽穗期氮、磷、钾养分向籽粒的转运,施氮量180 kg/hm 2 处理抽穗期各养分累积量与籽粒转运量呈正比,当氮肥用量超过180 kg/hm 2 后,氮、磷、钾养分向籽粒转运出现负效应。氮素农学利用率和偏生产力随着施氮水平的提高而显著下降,氮肥当季回收率以施氮量180 kg/hm 2 处理最高。相关分析表明,水稻主要生育期氮、磷、钾的吸收、转运与产量间均存在显著或极显著的正相关性,其中灌浆期氮、磷、钾的吸收状况与产量间的相关系数最大。施用氮肥可显著提高收获后0—100 cm土壤中残留无机氮(N min ),氮素表观损失量随施氮水平的提高而增加。【结论】适宜的氮肥用量可显著提高水稻产量,各生育时期养分吸收总量,提高水稻生育后期秸秆中氮、磷、钾向籽粒的转运量,并能降低土壤氮素表观损失量。综合考虑提高水稻产量、效益、氮肥当季回收率及维持土壤氮素平衡等因素,在本试验条件下,施氮范围在192.9～219.6 kg/hm 2 。

Fertilizers can become a source of pollution when they are used in excess. Reducing application rate of fertilizer-nitrogen use and increasing efficiency of fertilizer-nitrogen use for irrigate rice is an important task for the agricultural scientists. In this paper, research advances on relationship between efficiency of fertilizer-nitrogen use and the application method of fertilizer-nitrogen use, rice genotype differences, root growth, matter accumulation, physiological metabolism, plant characteristics were reviewed. Rice variety with stronger root system was in favor of raising the absorptive capacity of soil nitrogen; Stronger tillering ability, higher grain-leaf ratio at full heading stage, dry matter accumulation after heading stage, seed-setting rate, grain weight, yield and harvest index of cultivars resulted in higher nitrogen use efficiency. Its physiology characteristics were characterized by higher activities of nitrate reductase, glutamate synthase and the activity of RuBP carboxylase. Ways of increasing fertilizer-nitrogen use efficiency (i.e. balancing between N and P, K, improving method of fertilizer-nitrogen and water management, and applying accurately fertilizer-nitrogen), were also discussed. At last, research hotspots regarding N losses reduction and N use efficiency enhancement were put forward.

本文综述了国内外有关水稻基因型、根系生长、物质积累、生理代谢、植株性状与氮素利用效率关系的研究进展。指出水稻发根力强、根系发达的品种有利于提高对土壤氮素的吸收能力；分蘖力强，齐穗期粒叶比大，抽穗后干物质积累量大，库容量大，结实率、千粒重、生物产量和收割指数高的品种对氮素的利用效率高；其生理学特征表现为硝酸还原酶、谷氨酸合成酶和RuBP羧化酶的活性高。总结了从氮肥种类与平衡施肥、施肥方法与肥水运筹、氮肥精准施用技术方面提高稻田氮肥利用率的有效途径。提出了提高水稻氮效率的研究重点，即建立水稻氮素效率间接评价的有效方法、突出水稻氮素效率的遗传规律与品种选育工作、协调氮素高效吸收与高效利用矛盾的栽培策略和深化以叶色为基础的高效定量施氮技术研究4个方面。

Abstract: To further understand characteristics of nitrogen （N） utilization efficiency in different rice genotypes with varied grain yields， which would be helpful for the breeding of rice cultivars with higher N use efficiency， field experiments were conducted in Jiaxing City， Zhejiang Province. Grain yield， N accumulation， N translocation efficiency and amount， N physiological use efficiency of 10 rice cultivars in 3 study sites were analyzed. The results showed that rice grain yield and other indexes related to N utilization properties among rice cultivars were significantly different in each study site. The same results were also found among 3 study sites for each rice genotype. Furthermore， rice cultivars had significant interaction with study sites. There were significantly（P

摘要：为了明确在产量方面有差异的不同基因型水稻的氮利用特性及其影响因子，以便为氮高效水稻品种的选育提供理论指导，本研究选取了10个基因型水稻品种和3个供试点，对水稻产量、氮累积、氮转运效率和转运量以及氮生理利用效率进行研究，并分析各指标间的相关关系。结果表明：在同一供试点不同基因型水稻间的产量和氮利用特性相关指标均存在显著差异，同一基因型水稻在不同供试点也存在明显差异，不同基因型品种水稻和供试点间的交互作用亦可对氮利用特性发挥明显作用。水稻产量与总氮累积、齐穗期氮累积、氮转运量和氮生理利用效率均呈极显著（P

Nitrogen(N) plays a key role in the formation of crop yield and quality. This paper reviews the rational N application which includes rate, time and method, and also includes combinations of manure and straw etc. It points out that the severe N loss in the applied process and after fertilization is the main problem of fertilization in Chinese cropland. Based on the farmer investigation and the rational N rate from the field experiments, the proportion of overuse N of farmers’ fields occupies about 33% of total investigated fields. However, on the basis of regional scale, comparing with average recommended N rate, the average N rate per sowing area for overuse, rational and insufficient N rate account for 20%, 70% and 10% of the total sowing area, respectively. Generally, the phenomenon of overuse is common, especially in cash crop such as vegetable and fruit tree. We further proposed a method for estimating national N fertilizer demand in this paper. By using three different kinds of estimating method and comparing with actual national total N fertilizer consumption from 1980 to 2010, the actual total N fertilizer consumption is not excessive (27.9×10 6 t N annually from 2006 to 2010) if extensive fertilization;  but if with the improved fertilization techniques, the total N fertilizer consumption should be about 19.6×10 6 t N annually from 2006 to 2010. Using five different kinds of predicting method shows that the national rational N demand for 2020, 2030 and 2050 is 21.0×10 6  t N, 21.7×10 6  t N and 23.1×10 6   t N, respectively, if we improve the fertilization technologies. On the contrast, the national rational N demand for 2020, 2030 and 2050 is 30.4×10 6  t N, 31.4×10 6   t N and 334×10 6  t N if we still use extensive fertilization. This paper further analysis the differences among China, the US and the Western Europe on the crop production and N fertilization rate. It also further analysis the importance of manure and carbon application on enhancing soil organic carbon and N pools in Chinese cropland.

氮素在作物产量和品质形成中起着关键作用。本文综述了什么是合理施氮，包括施氮量、 施氮方法和时期，也包括与有机肥和秸秆还田措施的配合等。指出我国农田氮肥施用的主要问题是施肥过程和施肥后的严重损失。依据农户调查所获得的田块尺度施氮量，与田间试验合理施氮量对比分析表明，过量施氮田块占总调查田块的大约33%。依据区域尺度单位播种面积平均施氮量，与作物平均推荐施氮量对比分析表明，全国过量施氮面积占播种面积20%、 合理面积占70%、 不足面积占10%。总体而言，过量施氮现象还相当普遍，特别是在蔬菜和果树等经济作物上。本文提出了一种估算国家尺度氮肥需求量的方法，可估算出全国合理需氮量范围，称之为氮肥需求量估算法。用三种不同方法估算的我国19802010年间的氮肥需求量与实际氮肥使用量比较表明，如仍然依照现在的粗放施肥习惯，应该为现在的实际氮肥使用量，5年平均为N 27.9×10 6 t 左右，正好处于合理需氮量范围的中线。在改善施肥技术基础上，我国2006~2010年间5年氮肥平均使用量应该在N 19.6×10 6 t 左右；用五种方法预测的我国未来氮肥需求量表明，如果改善施肥技术，我国2020、 2030、 2050年合理氮肥需求量分别为N 21.0×10 6 t、 21.7×10 6 t、  23.1×10 6 t；如施肥技术得不到实质性改善，依然粗放施氮，则氮肥需求量应处于合理使用量范围的中线，分别为N 30.4×10 6 t、 31.4×10 6 t、 33.4×10 6 t。进一步分析了我国粮食产量和氮肥施用量与美国和西欧的差异，我国农田有机肥和碳投入对增加土壤有机碳氮库的重要性。