我国稻田氮肥利用现状及对策

介绍了我国水稻生产中氮肥使用和利用情况,并从稻田土壤背景氮、杂交水稻和超级稻的应用、施肥时期和比例不合理、中期晒田等多方面分析了我国水稻氮肥利用率低的可能原因.初步探讨了从选育节氮高效水稻品种、研发和应用新型氮肥、改进稻田施肥时期和方法、科学使用硝化抑制剂和脲酶抑制剂及节肥新技术推广应用等方面来提高水稻氮肥利用率的研究策略.     

Mapping of QTLs for Nitrogen Use Efficiency and Related Traits in Rice( Oryza sativa L.)

Current rice production is usually guaranteed by applying large amount of chemical nitrogen fertilizers to paddy soils. The improvement of nitrogen use efficiency is of great importance not only in rice production itself but in environmental protection as well. In this study we performed a molecular marker-based genetic analysis of nitrogen use efficiency for biomass production (NUEp) and several other related traits in a recombinant inbred line (RIL) population, derived from a cross of the parents of Shanyou 63, the most widely cultivated indica hybrid in China. A total of 12 QTLs were detected using interval mapping with a LOD threshold of 2.0, among which one QTL controlling NUEp was located at the marker interval of Waxy-C1496 on chromosome 6, and the rest 11 QTLs associated nitrogen concentration and accumulation in rice plant were positioned on chromosomes 1, 2, 4 and 6, respectively. Correlation between NUEp and other traits was analyzed and the implications of the results with respect to the improvement of the hybrid rice were discussed.     

水稻高产与氮肥高效利用技术及其生物学基础

氮素是作物生产上施用量最多的肥料,氮肥施用量过多是我国水稻生产上的突出问题。介绍了氮肥施用方法对水稻产量和氮肥利用效率的影响及其生物学基础,并对实现水稻高产与氮肥高效利用提出了建议。     

减量施氮对水稻生长和肥料利用效率的影响

[目的]确定氮肥减量施用对巢湖流域水稻生长、氮肥利用效率的影响。[方法]通过田间小区试验,以施氮量180 kg/hm2为基础,设置0、60%、80%和120%N施用量5个处理。在水稻成熟期,采集25株考种样,测定产量构成性状,并且测定每个小区籽粒产量。[结果]适当减少氮肥施用量对水稻生长发育的影响不明显,2年试验水稻籽粒产量分别比对照提高-1.63%～1.92%和-2.36～2.57%,平均增产0.32%和0.34%,基本持平;氮肥偏生产力、农学效率、生理效率及表观利用率均明显提高,且随着氮肥施用量的下降而增大。[结论]在当前生产水平下,在巢湖流域水稻土区适当减少氮肥施用量对水稻生长和籽粒产量影响不大,同时可明显提高氮肥利用效率,有利于环境保护。     

平原河网区水稻养分的利用效率研究

[目的]研究潜江市平原河网区水稻的养分利用效率。[方法]通过田间试验,研究了习惯施肥和配方施肥处理对水稻产量、肥料投入、养分表观协同利用率、肥料农学效率、水稻籽粒和茎叶养分含量的影响。[结果]氮、磷、钾3者配施时肥料的表观利用率最高;与习惯施肥处理相比,配方施肥处理能提高肥料的农学效率、肥料养分利用率,并能促进氮的吸收,可增产3.45%,增收944.2元/hm~2。[结论]该研究为优化施肥结构,提高肥料养分利用率提供理论基础。     

不同氮素籽粒生产效率类型籼稻品种氮素吸收利用的差异(英文)

[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002, respectively. Dry matter weight (including root system, culm and sheath, leaves, panicle), nitrogen content of different organs, yield and its components were measured. The tested rice cultivars were classified into 6 types (i.e. A, B, C, D, E and F, A was the lowest, and F was the highest) based on their NUEg level by the MinSSw method.[Result](1)Difference of NUEg of the cultivars used in this study were very large; (2) No significant difference of N content at heading stage was observed among different NUEg types of indica rice. In the cultivars with higher NUEg, however, N content in leaf, stem-sheath and entire rice plant were lower at mature stage. (3)Cultivars with higher NUEg were characterized with lower N uptake before heading and at mature stage; (4) Cultivars with higher NUEg were characterized with higher N use efficiency in biomass production and harvest index. [Conclusion] The cultivars with higher NUEg showed lower N uptake and N content, while nitrogen use efficiency was higher.     

氮肥运筹对土壤-小麦系统氮素行为及氮素利用效率影响的研究进展

氮肥大量用于农业生产中,不仅降低了氮素利用效率,而且对生态环境产生了不良影响。根据国内外研究情况,综述了土壤中氮素的形态及其转化途径、施氮对土壤氮素含量及分布的影响、小麦植株对氮素的吸收同化及分配机理、施氮对氮素利用效率的影响。     

Effects of Nitrogen Application on Photosynthetic Characteristics and Nitrogen Use Efficiency in Wheat after Rice

In the present study,appropriate nitrogen (N) application mode in Jianghan Plain was explored by investigating the effects of different N applications on the photosynthetic characteristics of flag leaves and nitrogen use efficiency (NUE) in a wheat cultivar Zhengmai 9023.Nitrogen was top-dressed before sowing,before winter,and during the jointing stage,at different ratios:1∶1∶0 (N1),1∶0∶1 (N2),2∶1∶1 (N3),1∶1∶1 (N4),and 0∶0∶1 (N5),under the same amount of total N (180 kg/hm2) during the growing season.No nitrogen fertilizer was used in the control (NO).Results showed that the SPAD values and photosynthetic rate (Pn) of different treatments in flag leaves increased initially and then decreased around the anthesis stage.The two indices in N1 and N5 treatments decreased rapidly after flowering,whereas those in N2,N3,and N4 treatments maintained at high levels for a long period after anthesis.Thus,reasonable nitrogen application could retard the decline of SPAD and Pn after anthesis.N4 and N1 treatments showed large dry matter accumulation.In decreasing order of crop yield,the treatments were:N4＞N1 ＞ N3＞N5＞N2＞N0.The effective panicle number and grain number per spike of N2 were significantly lower than those of other treatments,and there was no significant difference among other treatments.No significant correlation was found between nitrogen application and 1 000-grain weight in this experiment.The nitrogen accumulation,agronomic efficiency of nitrogen fertilizer,nitrogen uptake and use efficiency of above-ground parts,nitrogen uptake and use efficiency of grain of N4 treatment were higher than those of other treatments,but the nitrogen harvest index of N4 was at a low level.In summary,N4 treatment is the most suitable nitrogen application mode in wheat after rice.     

水稻氮素籽粒生产效率遗传分析

[目的]了解不同氮环境中水稻氮素籽粒生产效率的遗传特点。[方法]采用Dasanbyeo×TR22183杂交,构建了163个家系组成的重组自交系群体(RILs),利用主基因+多基因混合遗传模型,研究施氮、不施氮处理的水稻氮素籽粒生产效率的遗传机制。[结果]两亲本的氮素籽粒生产效率在不同处理中均存在统计学差异,RILs群体的变幅较大,极显著差异,且呈连续变异。水稻氮素籽粒生产效率属两对主基因+多基因控制,在施氮处理下的最适模型为E-1-4模型,主基因表现为显性上位作用,遗传率为51.03%,且两对主基因的加性效应不同;在未施氮处理下的最适模型为E-1-9,主基因表现为抑制作用,遗传率为41.10%。主基因间包括加性和加性上位互作效应。[结论]水稻氮素籽粒生产效率在不同的氮环境中均属两对主基因+多基因遗传控制,主基因遗传率在施氮环境中表现相对较高。     

Advances in Research on the Approaches of Improving Water Utilization Efficiency in Rice

Water shortage is increasingly an important factor limiting the sustainable development of global economy, posing a huge threat to social security and human existence. Water usage in agriculture accounts for about 70% of total water consumption in the world, and rice cultivation is in turn the largest water user, which accounts for about 50% of total water usage in agriculture. Therefore, it is quite important to improve water utilization efficiency to reduce water consumption in rice.Water stress causes severe inhibition of plant growth and development as well as yield reduction, however the extent of inhibition or reduction varies greatly with the growth stages, duration and severity of stress, and plant genotypes. In rice,drought resistance and water utilization efficiency might be improved by developing stress resistant cultivars and conducting proper agronomic practices. It is hence imperative to determine the suitable criteria in morphological and physiological traits for drought resistance and water utilization efficiency in conventional breeding of rice. At present, leaf rolling, leaf water potential and carbon isotope discrimination are commonly used criteria for the evaluation and identification of germplasm with high drought resistance or water utilization efficiency. With rapid development of molecular biology,marker-assisted selection has been used in rice breeding against water stress. In this review, therefore, the agronomic aspect of water saving techniques such as selection of suitable rice cultivars, planting pattern, mulching, deficit irrigation and alternative drying and moist irrigation are discussed and effective approaches are also recommended.