多熟制是我国作物种植制度的重要特征,也是进一步提高粮食产能的重要途径。本文回顾了我国稻田复种制度的起源,简述了新中国成立以来我国稻田种植制度的演化历程,概述了当前我国主要存在的稻田复种轮作模式,并对我国稻田种植制度的发展方向作出了展望。

Multiple cropping is one of the important farming systems in China, which improves the comprehensive production capacity of arable land and ensures national food security. This paper introduced the origin of paddy multiple cropping system in China, reviewed the development status of paddy multiple cropping system in detail over the past 70 years, introduced the current main paddy-upland multiple cropping rotation system in China. Finally, the future of paddy multiple cropping system was discussed.

. Open biomass burning (OBB) has a high potential to\ntrigger local and regional severe haze with elevated fine particulate\nmatter (PM2.5) concentrations and could thus deteriorate ambient air\nquality and threaten human health. Open crop straw burning (OCSB), as a\ncritical part of OBB, emits abundant gaseous and particulate pollutants,\nespecially in fields with intensive agriculture, such as in central and eastern\nChina (CEC). This region includes nine provinces, i.e., Hubei, Anhui, Henan, Hunan,\nJiangxi, Shandong, Jiangsu, Shanghai, and Fujian. The first four ones are\nlocated inland, while the others are on the eastern coast. However,\nuncertainties in current OCSB and other types of OBB emissions in chemical\ntransport models (CTMs) lead to inaccuracies in evaluating their impacts on\nhaze formations. Satellite retrievals provide an alternative that can be\nused to simultaneously quantify emissions of OCSB and other types of OBB,\nsuch as the Fire INventory from NCAR version 1.5 (FINNv1.5), which,\nnevertheless, generally underestimates their magnitudes due to unresolved\nsmall fires. In this study, we selected June 2014 as our study period,\nwhich exhibited a complete evolution process of OBB (from 1 to 19 June) over\nCEC. During this period, OBB was dominated by OCSB in terms of the number of\nfire hotspots and associated emissions (74 %–94 %), most of\nwhich were located at Henan and Anhui (> 60 %) with intensive\nenhancements from 5 to 14 June (> 80 %). OCSB generally\nexhibits a spatiotemporal correlation with regional haze over the central part\nof CEC (Henan, Anhui, Hubei, and Hunan), while other types of OBB emissions\nhad influences on Jiangxi, Zhejiang, and Fujian. Based on these analyses, we\nestablish a constraining method that integrates ground-level PM2.5\nmeasurements with a state-of-art fully coupled regional meteorological and\nchemical transport model (the two-way coupled WRF-CMAQ) in order to derive\noptimal OBB emissions based on FINNv1.5. It is demonstrated that these\nemissions allow the model to reproduce meteorological and chemical fields\nover CEC during the study period, whereas the original FINNv1.5\nunderestimated OBB emissions by 2–7 times, depending on\nspecific spatiotemporal scales. The results show that OBB had substantial\nimpacts on surface PM2.5 concentrations over CEC. Most of the OBB\ncontributions were dominated by OCSB, especially in Henan, Anhui, Hubei, and\nHunan, while other types of OBB emissions also exerted an influence in Jiangxi,\nZhejiang, and Fujian. With the concentration-weighted trajectory (CWT)\nmethod, potential OCSB sources leading to severe haze in Henan, Anhui,\nHubei, and Hunan were pinpointed. The results show that the OCSB emissions\nin Henan and Anhui can cause haze not only locally but also regionally\nthrough regional transport. Combining with meteorological analyses, we can\nfind that surface weather patterns played a cardinal role in reshaping\nspatial and temporal characteristics of PM2.5 concentrations.\nStationary high-pressure systems over CEC enhanced local PM2.5\nconcentrations in Henan and Anhui. Then, with the evolution of\nmeteorological patterns, Hubei and Hunan in the low-pressure system were\nimpacted by areas (i.e., Henan and Anhui) enveloped in the high-pressure\nsystem. These results suggest that policymakers should strictly undertake\ninterprovincial joint enforcement actions to prohibit irregular OBB,\nespecially OCSB over CEC. Constrained OBB emissions can, to a large extent,\nsupplement estimations derived from satellite retrievals as well as reduce\noverestimates of bottom-up methods.\n

Livelihood diversification is beneficial to mitigate economic and environmental risks and to improve livelihood sustainability and regional sustainable development. Unsettled herder households (UHH), settled herder households (SHH) and farmer households (FH) are different household types in far northwestern China whose livelihood diversification has not been fully explored. By applying a framework of livelihood diversification, this paper presents a comparative analysis of the characteristics and determinants of the diversification of the three household types. The results show that livelihood assets have been unequally distributed, with FH possessing the least assets; however, FH are better than UHH and SHH in the diversification of livelihood activities. Agriculture remains the most important livelihood source. The high-income groups of the three household types have a higher number of livelihood activities but do not necessarily hold an advantage in equality of livelihood activities. Labor capacity and income are positively related to the number of livelihood activities for the three household types. Livestock size is negatively associated with the number of activities of herders. Moreover, age and subsidy have negative impacts on the number of activities for UHH. Based on the findings, we provide policy suggestions on livelihood enhancement and sustainable and effective development of pastoral regions.

Agronomic practices such as crop residue return and additional nutrient supply are recommended to increase soil organic carbon (SOC) in arable farmlands. However, changes in the priming effect (PE) on native SOC mineralization in response to integrated inputs of residue and nutrients are not fully known. This knowledge gap along with a lack of understanding of microbial mechanisms hinders the ability to constrain models and to reduce the uncertainty to predict carbon (C) sequestration potential. Using a C-labeled wheat residue, this 126-day incubation study examined the dominant microbial mechanisms that underpin the PE response to inputs of wheat residue and nutrients (nitrogen, phosphorus and sulfur) in two contrasting soils. The residue input caused positive PE through "co-metabolism," supported by increased microbial biomass, C and nitrogen (N) extracellular enzyme activities (EEAs), and gene abundance of certain microbial taxa (Eubacteria, β-Proteobacteria, Acidobacteria, and Fungi). The residue input could have induced nutrient limitation, causing an increase in the PE via "microbial nutrient mining" of native soil organic matter, as suggested by the low C-to-nutrient stoichiometry of EEAs. At the high residue, exogenous nutrient supply (cf. no-nutrient) initially decreased positive PE by alleviating nutrient mining, which was supported by the low gene abundance of Eubacteria and Fungi. However, after an initial decrease in PE at the high residue with nutrients, the PE increased to the same magnitude as without nutrients over time. This suggests the dominance of "microbial stoichiometry decomposition," supported by higher microbial biomass and EEAs, while Eubacteria and Fungi increased over time, at the high residue with nutrients cf. no-nutrient in both soils. Our study provides novel evidence that different microbial mechanisms operate simultaneously depending on organic C and nutrient availability in a residue-amended soil. Our results have consequences for SOC modeling and integrated nutrient management employed to increase SOC in arable farmlands.© 2018 John Wiley & Sons Ltd.

Soil sustainability is based on soil microbial communities’ abundance and composition. Straw returning (SR) and nitrogen (N) fertilization influence soil fertility, enzyme activities, and the soil microbial community and structure. However, it remains unclear due to heterogeneous composition and varying decomposition rates of added straw. Therefore, the current study aimed to determine the effect of SR and N fertilizer application on soil organic carbon (SOC), total nitrogen (TN), urease (S-UE) activity, sucrase (S-SC) activity, cellulose (S-CL) activity, and bacterial, fungal, and nematode community composition from March to December 2020 at Guangxi University, China. Treatments included two planting patterns, that is, SR and traditional planting (TP) and six N fertilizer with 0, 100, 150, 200, 250, and 300 kg N ha–1. Straw returning significantly increased soil fertility, enzymatic activities, community diversity, and composition of bacterial and fungal communities compared to TP. Nitrogen fertilizer application increased soil fertility and enzymes and decreased the richness of bacterial and fungal communities. In SR added plots, the dominated bacterial phyla were Proteobacteria, Acidobacterioia, Nitrospirae, Chloroflexi, and Actinobacteriota; whereas fungal phyla were Ascomycota and Mortierellomycota and nematode genera were Pratylenchus and Acrobeloides. Co-occurrence network and redundancy analysis (RDA) showed that TN, SOC, and S-SC were closely correlated with bacterial community composition. It was concluded that the continuous SR and N fertilizer improved soil fertility and improved soil bacterial, fungal, and nematode community composition.

【目的】研究麦秆还田下不同水氮耦合对麦茬杂交籼稻氮素吸收利用及产量的影响。【方法】以杂交稻F优498为材料，设置不同水分处理方式(干湿交替灌溉、淹水灌溉)、氮肥运筹 [总氮150 kg/hm²，基肥∶蘖肥∶穗肥分别为3∶3∶4(N1)、7∶3∶0(N2)、不施氮(N0)]和秸秆还田(秸秆全量翻埋还田、秸秆不还田)，测定还田秸秆氮素腐解率、水稻籽粒产量及主要生育时期各器官氮素吸收利用特征。【结果】干湿交替灌溉促进了秸秆氮素释放，使水稻在拔节期后的地上部氮素积累量提高4.85%~33.92%，提高成熟期茎鞘氮素转运能力，穗部氮素吸收量提高了10.73%~16.42%，最终提高有效穗数并增产2.51%~3.77%。秸秆还田释放氮素营养，提高拔节期后的水稻地上部氮素积累量5.15%~53.21%和成熟期叶片氮素转运能力，提高穗部氮素吸收量4.93%~ 43.91%，最终增产9.62%~18.33%。施氮促进了秸秆养分释放，提高了水稻植株氮素吸收与转运能力，增加了有效穗数并显著增产16.21%~28.31%。对比干湿交替灌溉耦合优化施氮(N1)模式与淹水灌溉耦合传统施氮(N2)模式，前者促进了各时期的秸秆养分释放，提高了地上部氮素积累能力和茎鞘及叶片的氮素转运能力，并显著提高了氮肥回收利用率7.27%~26.06%。【结论】麦秆全量翻埋还田条件下，干湿交替灌溉耦合优化施氮的水氮耦合模式可促进秸秆氮素释放，有效提高水稻氮素积累及利用能力，提高氮肥回收利用率与水分利用率，为本研究中最适水肥耦合模式。

【Objective】It is of significance to study the effects of different water and nitrogen coupling on nitrogen absorption, utilization and yield of indica hybrid rice with wheat straw returning.【Method】The nitrogen decomposition rate, nitrogen absorption and utilization were analyzed under two water treatments, three N treatments and two straw returning treatments with F You 498 as material with wheat straw returning at main growth stages. The two water treatments were alternative dry-wet irrigation and submerged irrigation and the straw returning treatments were full-burying returning and no straw returning and the N treatments were 150 kg/hm2 of N application rates with three N regimes—the ratio of the basal fertilizer, tillering fertilizer and panicle fertilizer were 3∶3∶4 (N1), 7∶3∶0 (N2) and 0 (N0), respectively.【Result】The results showed that the alternative dry-wet irrigation promoted the release of straw nitrogen, increased the aboveground nitrogen accumulation of rice after jointing by 4.85%－33.92%, improved the nitrogen transport capacity of stem and sheath at maturity, increased the nitrogen absorption of panicle by 10.73%－16.42%, finally leading to an increase in the number of effective panicles and grain yield by 2.51%－3.77%. Straw returning (S1) released nitrogen nutrition, increased the aboveground nitrogen accumulation of rice by 5.15%－53.21% and the nitrogen transport capacity of leaves at maturity, increased the nitrogen absorption of panicle by 4.93%－43.91%, and finally increased the yield by 9.62%－18.33%. Nitrogen application promoted the release of straw nutrients and improved the nitrogen absorption and transport capacity of rice plants, increased the number of effective panicles and significantly increased the yield by 16.21%－28.31%. Compared with the alternative dry-wet irrigation coupled with optimized nitrogen application (N1) mode, the flooding irrigation coupled with traditional nitrogen application (N2) mode promoted the release of straw nutrients, increased the aboveground nitrogen accumulation of rice by 1.17%－11.89%. It improved the aboveground nitrogen accumulation capacity and nitrogen transport capacity of stems, sheaths and leaves, and significantly improved the nitrogen recovery and utilization rate by 7.27%－26.06%.【Conclusion】Under the conditions of full burying of wheat straw and returning to the field, the alternative dry-wet irrigation coupled with optimized nitrogen application can promote the release of straw nitrogen, effectively improve the nitrogen accumulation and utilization capacity of rice, and improve the nitrogen recovery and utilization rate and water use efficiency. It is the most suitable water-fertilizer coupling model in this experiment.

This study is based on the Stanford equation and aims at getting high yield and high quality rice. With the aid of stage and monomial method of quantitative determination, the three parameters of the precise and quantitative N application theory and technology were measured and validated. In the process of study new, methods and route were found preliminarily, such as a new method for determination of the amount of N requirement by grading the yield of a field, a new route to study by demarcating the N supplied by organic fertilizer to the N supply ability of a field and the great effect of the ratio of N applied as basal fertilizer and that as panicle fertilizer on the NUE was proposed. The research has solved the technology of precise and quantitative N application of total amount of N and its splitting application, thus enabling the application of this technology and supporting the application of "3S" technology.

在田间定位试验条件下,研究了4个秸秆还田量水平[0 kg/hm²(S0)、4000 kg/hm²(S4)、6000 kg/hm²(S6)、8000 kg/hm²(S8) ]耦合4个施氮水平[0 kg/hm²(N0)、90 kg/hm²(N90)、180 kg/hm²(N180)、270 kg/hm²(N270) ]对水稻茎蘖动态、生育后期光合特性、干物质积累特征、氮素吸收和产量形成的影响。结果表明:1) 不施氮条件下,秸秆还田明显抑制水稻生育前期茎蘖的发生和茎蘖高峰的形成,促进水稻后期的干物质积累、氮素吸收,提高剑叶光合速率,稻谷产量增加2.22%~4.44%。2)氮肥单施条件下,随着施氮量的增加水稻茎蘖数和最高苗数显著增加,分蘖高峰提前7~14d;施氮显著增加水稻各生育期干物质积累量、氮素吸收量和稻谷产量,明显延缓水稻生育后期剑叶光合速率的下降。3) 同等施氮条件下,与S0相比,秸秆还田S4、S6处理促进水稻茎蘖发生,成熟期植株吸氮量显著增加,以S6处理增幅最大,平均增加36.58%,生育后期剑叶光合速率维持在较高水平;S8处理则对水稻茎蘖发生、光合作用和氮素吸收表现出负面影响。4) 秸秆还田耦合施氮量显著影响单位面积有效穗数和稻谷产量,与N0S0相比,两者配施水稻显著增产9.59%~23.51%,以N180S6处理产量最高,达10.56 t/hm²。适宜的秸秆还田量耦合施氮量可促进水稻茎蘖发生和有效穗形成,增加氮素和光合同化物积累,从而增加稻谷产量。

【目的】研究秸秆还田与水氮配施的理论与技术,探讨对水稻群体质量和产量形成的影响。【方法】选用宜香优2115为试验材料,三因素裂裂区设计,主区为油菜秸秆堆腐还田和直接还田两种秸秆还田方式,裂区为淹水灌溉和控制性交替灌溉两种水分管理方式,裂裂区为4种施氮量,分析对水稻群体质量及产量的影响,并探讨秸秆还田与水氮管理模式下群体质量和产量形成的关系。【结果】秸秆还田与水氮管理对主要生育时期水稻干物质积累量、叶面积指数(LAI)及产量均存在显著或极显著的调控效应,互作效应显著;且群体质量指标与产量呈显著或极显著正相关。秸秆堆腐还田对水稻群体质量指标的调控显著高于秸秆直接还田,齐穗期高效叶面积指数提高了4.71%~6.50%,群体干物质显著增加了9.22%~13.30%;并对水稻产量及其构成因素影响显著,有效穗数及每穗粒数分别提高了5.9%~9.8%和1.5%~5.2%,从而使产量提高了9.5%~13.4%。控制性交替灌溉相对于淹灌能保证足够的穗数,提高干物质积累量,减缓拔节至齐穗期叶面积衰减,加快结实期群体生长率,利于穗粒数及产量的提高;且随着氮肥用量的增加,分蘖数、干物质积累量、有效叶面积率和高效叶面积率均呈先增后降的趋势。【结论】从三因素间的互作效应来看,秸秆堆腐还田处理下,控制性交替灌溉与施氮量150 kg/hm²,可有效提高齐穂期高效叶面积指数(4.80~5.32),具有较高的结实期干物质积累量(6.94~7.36 t/hm²),显著提高了有效穗(181.6万~220.9万/hm²)及每穗粒数(180~200粒),从而显著提高产量达到10328.1~12464.1 kg/hm²,为本研究节水减氮增效最佳的处理。

【Objective】It has great significance to investigate the interaction mode between straw returning and water-nitrogen (N) management on rice population quality and yield.【Method】Hybrid rice (Yixiangyou 2115) was used as experimental materials with two straw retention ways as main plot (crop straw composting and direct straw returning) and conventional irrigation and alternate irrigation as split plot and four N rates as split-split plot. The relationship between population quality and yield of hybrid rice were also analyzed.【Results】Straw returning and water-nitrogen (N) management exert significant or extremely significant effects on biomass accumulation of hybrid rice, LAI and grain yield. Correlation analysis indicated that there existed significantly or highly significantly positive correlations between population quality index and yield. The straw composting had a highly significant effect on population growth rate and grain yield compared with direct straw returning, the high valid leaf area index at the full heading stage increased by 4.71%-6.50%, Dry matter weight of population during maturity increased by 9.22%-13.30%, and the effective panicle number increased by 5.9%-9.8%, the spikelet number by 1.5%-5.2%, the yield by 9.5%-13.4%. Compared with conventional irrigation, controlled alternative irrigation could ensure sufficient panicle number, increase dry matter accumulation, slow down leaf area attenuation rate from jointing stage to full heading stage, accelerate population growth rate at seed-setting stage, and increase grain number per panicle and yield significantly. With the increase of nitrogen rate, the number of tillers, dry matter accumulation, effective leaf area ratio and effective leaf area rate all increased at first and then decreased. 【Conclusion】 From the perspective of the effect of the three factors, straw composting, alternative irrigation, 150 kg/hm2 nitrogen level were the optimum treatment of water saving and N reduction in this experiment. It can significantly improve efficient LAI of full heading (4.80-5.32), enhance the high dry matter accumulation rate during filling stage (6.94-7.36 t/hm2), notely increase effective panicle number (181.6×104-220.9×104/hm2) and grain number per panicle(180-200), achieving grain yield of hybrid rice of 10328.1-12464.1 kg/hm2.

轻简化栽培和优质稻是当前我国水稻生产的主要方向,气象因子是对水稻生长发育和产量形成影响最大的环境因素,但在不同轻简化栽植方式下水稻产量与其田间小气候的关系鲜有研究。为探究西南地区不同前作下杂交稻各生育阶段温、光和水等气候因子与水稻产量形成的关系,在2019—2020年,以杂交籼稻‘宜香优2115'为试验材料,采用两因素裂区设计,主区为青菜和油菜2种前作,副区为机直播、毯苗机插和人工移栽3种栽植方式,研究杂交稻产量对气候因子的响应及水稻植株对温光资源的利用。结果表明: 与油菜-水稻模式相比,青菜-水稻模式下杂交稻积温生产效率和降水生产效率显著提高,进而提高了有效穗数、结实率和千粒重,2年产量分别提高了12.7%和8.3%。与人工移栽相比,机插稻提高了单位面积有效穗数、全生育期光能生产效率、积温生产效率、籽粒光能利用效率和降水生产效率,2年平均产量提高了4.6%;而机直播全生育期降水生产效率、光能生产效率、积温生产效率、籽粒光能利用效率、每穗粒数和千粒重都显著降低,导致2年平均产量下降了8.7%。与2019年相比,2020年机插稻和人工移栽稻在同一茬口下提前一个月播种造成花后生育期缩短、气温降低和降雨量增多,导致有效积温和光辐射量大幅减少,积温生产效率、光能生产效率、降水生产效率和籽粒光能利用效率以及每穗粒数、结实率和千粒重均大幅降低,进而导致产量严重降低。用偏最小二乘法回归分析建立的气象因子产量预报方程标准化回归系数显示,水稻产量与阶段生育期或全生育期内有效积温和总辐射量呈正相关关系,与全生育期内降水量呈显著负相关关系。综上,青菜-水稻模式下机插秧与西南地区稻季光温资源匹配度最高,更有利于温光资源的充分利用和获得高产,但不宜过早播种或移栽。

本研究旨在阐明干湿交替灌溉影响水稻产量的生理机制。大田种植3个当地高产水稻品种武运粳24 (粳稻)、扬两优6号(两系杂交籼稻)与甬优2640 (三系籼/粳杂交粳稻)。自移栽后7 d设置：常规灌溉(CI，保持水层)和干湿交替灌溉(AWD)，观察这2种灌溉模式对水稻根系与地上部生长发育的影响。结果表明，与CI相比，AWD可以显著提高水稻产量与水分利用效率，3个供试品种产量分别提高了5.34%、5.85%和6.62%，水分利用效率分别提高了28.9%、25.3%和27.6%。产量与水分利用效率的提高主要得益于水稻根系和地上部植株的生理功能的改善，表现出灌浆期较高的根系氧化力、根系伤流液强度、根系与叶片中玉米素与玉米素核苷的含量、剑叶净光合速率、籽粒中较高的蔗糖合酶、腺苷二磷酸葡萄糖焦磷酸化酶和淀粉合酶活性、较大的深层(10~20 cm)根系、较高的分蘖成穗率与叶面积指数。

Alternate wetting and drying (AWD) irrigation has been widely adopted to replace conventional irrigation (CI) for saving water and increasing water use efficiency (WUE) in irrigated rice systems in China. However, there is limited information about how AWD affects yield, WUE, and root and shoot growth and development. To fill this knowledge gap, we conducted the experiment using three local high-yielding rice cultivars, Wuyunjing 24 (japonica), Yangliangyou 6 (two-line indica hybrid rice) and Yongyou 2640 (three-line indica/japonica hybrid rice) under the two water managements, CI and AWD, during the whole growing season. The results showed that, when compared with CI, AWD increased grain yield by 5.34%, 5.85%, and 6.62% and WUE by 28.9%, 25.3%, and 27.6%, respectively which mainly attributed to greater root oxidation activity, amount of root bleeding sap, content of cytokinins (zeatin + zeatin riboside) in roots and leaves, highten photosynthetic rate of flag leaf, deeper root distribution, increased productive tillers and leaf area, and enhanced activities of enzymes involved in sucrose-to-starch conversion in grains during grain filling. The results demonstrate that AWD is an effective practice to increase grain yield and water use efficiency through enhancing root and shoot growth and development.

为明确双季稻区不同冬季覆盖作物秸秆还田对后茬水稻植株干物质和养分积累与分配的影响，选择不同冬季覆盖作物-双季稻种植模式为研究对象，采取田间小区定位试验，以冬闲-双季稻种植模式为对照(CK)，开展了黑麦草-双季稻(Ry-R-R)、紫云英-双季稻(Mv-R-R)、油菜-双季稻(Ra-R-R)和马铃薯-双季稻(Po-R-R)种植模式下不同冬季覆盖作物秸秆还田后对后茬水稻各部位干物质和氮、磷、钾积累与分配影响的研究。结果表明：早稻成熟期，Po-R-R处理茎、叶物质贡献率均高于其他处理；晚稻成熟期，Ra-R-R处理的茎、叶物质转运率和物质贡献率均高于其他处理。早稻成熟期，Mv-R-R处理水稻植株穗和地上部分的氮素和磷素积累量均显著高于CK处理（P<0.05）；各秸秆还田处理水稻植株茎和地上部分的钾素积累量均显著高于CK处理（P<0.05）。晚稻成熟期，Po-R-R处理叶、穗和地上部分的氮素和磷素积累量均显著高于CK处理（P<0.05）。Mv-R-R处理穗和地上部分的钾素积累量均显著高于Ry-R-R、Ra-R-R和CK处理（P<0.05）。总的来说，各冬季覆盖作物秸秆还田措施均促进了水稻各部位干物质积累和转运；其中以紫云英秸秆还田处理有利于水稻群体养分的积累与转运。

为了探讨不同类型高产水稻水氮高效利用特性,以大穗型杂交粳稻甬优8号和穗粒兼顾型常规粳稻品种(系)苏10-100为材料,进行实地氮肥管理和全生育期轻干-湿交替灌溉技术联合运用,研究水稻干物质和茎鞘非结构性碳水化合物(NSC)积累与运转特性及其与籽粒产量形成的关系。结果表明,与常规水肥管理相比,实地氮肥管理和轻干-湿交替灌溉联合运用显著增加了幼穗分化期至成熟期的干物质积累量和抽穗期茎鞘中NSC含量,提高了茎鞘干物质和NSC运转率和对籽粒的贡献率,大穗型杂交粳稻甬优8号的运转率和贡献率明显大于常规粳稻苏10-100;水氮处理降低了穗数,但显著或极显著地提高了每穗粒数、结实率、充实度和千粒重,苏10-100和甬优8号分别增加了6.21%、2.53%,1.68%、13.63%,3.3%、8.1%和9.06%、10.35%,其中2个弱势籽粒千粒重的增幅分别达到了16.3%和15.9%,显著大于强势粒。因此,采用实地氮肥管理和轻干-湿交替灌溉水稻具有中后期单位面积干物质积累量大,物质运转率高,穗大且多,结实率高、充实度好的特点,有利于促进弱势籽粒灌浆充实,提高籽粒产量。本研究为水稻超高产栽培和不同类型水稻养分水份高效管理提供理论依据和实践指导。

在高产施氮量180 kg hm^-2条件下，以杂交稻冈优527为材料，通过“淹水灌溉”(W₁)、“湿润灌溉(前期)+浅水灌溉(孕穗期)+干湿交替灌溉(抽穗至成熟期)”(W₂)和“旱种”(W₃) 3种灌水及不同的氮肥运筹处理，研究水分管理和氮肥运筹对水稻养分吸收、转运、分配及产量的影响，并探讨各养分间及其与产量的相互关系。结果表明，水分管理和氮肥运筹对水稻主要生育期氮、磷、钾的累积、转运、分配及产量的影响均存在显著的互作效应，水氮互作条件下各生育期氮、磷、钾间的吸收存在显著的协同效应；抽穗期氮、磷、钾的累积与各养分在结实期转运总量间，以及结实期各养分转运间均呈极显著正相关，且氮、钾在抽穗前期的累积对促进结实期各养分向籽粒的转运和提高产量影响显著，但氮肥后移比例过重(N₄处理)及W₃处理均会导致结实期叶片和茎鞘各养分转运总量的显著降低，氮、磷、钾降幅分别达2.73%~18.00%、8.03%~19.70%、6.52%~17.02%。据产量及其与养分吸收、转运间关系的表现，W₁模式下氮肥后移量以占总施氮量的40%~60%为宜，W₂模式与氮肥运筹方式为基肥:蘖肥:孕穗肥(倒四、二叶龄期分2次等量施入)=3∶3∶4组合是本试验最佳的水氮耦合运筹模式，W₃模式下，应减少氮肥的后移量，氮肥后移量占总施氮量的20%~40%为宜。