本文对我国油菜生产区域布局的演变和成因进行了分析。结果表明，目前我国以长江流域冬油菜区、北方春油菜区为优势发展区域布局格局的形成，除了气候、耕作制度、种植习惯和与粮食作物的关系等原因，科技创新和国家优势区域布局的双重推动起到了至关重要的作用。根据优势区的发展特点和趋势，提出了相关政策建议。

国家政策扶持力度的强弱会直接影响一个产业的发展,对于油菜籽产业来说,更是如此.前不久,国家出台了油菜籽最低收购价等政策,以确保农民种植油菜的利益.在国家政策的支持下,产区农民种植油菜的积极性大幅提高.据农业部预计,2009年我国冬油菜播种面积将突破660万公顷,比上年增长80万公顷.随着国家支农惠农政策的不断加强,我国油菜籽产业将迎来新的发展契机.

介绍了油菜矮杆抗倒新品系的来源、特征特性、遗传组成和利用价值.该品系来自于油菜芥甘种间杂交后代,具有矮杆抗倒、早熟高产高油分、超低硫苷、较高油酸含量等优良特性.随机扩增多态性DNA标记分析表明,其具有10%以上的芥菜型油菜遗传物质.该品系有望直接作为新品种推广应用,也可作为杂交亲本转育成矮杆抗倒品种或杂种亲本,从而开创矮杆油菜新时代,推动油菜机械化生产向前发展.

【Objectives】 The reasonable nitrogen fertilizer management strategies in rapeseed(Brassica napus L.) with high planting density(36×10 4 plant/hm 2 )and direct-sown conditions were studied. 【Methods】 Two field experiments were conducted in Chengdu Plain under a rice-rapeseed rotation system. The effects of different N rates(0, 90, 180, 270, 360 kg/hm 2 ) in the same N application mode(a basal fertilizer and a top dressing) and different N application modes(single application of basal fertilizer, twice application of a basal fertilizer and a top dressing, three times of application as a basal fertilizer and two top dressings) in the same N rate(225 kg/hm 2 ) on yield, quality and nitrogen fertilizer use efficiency in rapeseed were studied.【Results】 The results indicated that the increase of N application rates demonstrated an enhancement trend in agronomic traits in direct-sown rapeseed. However, the effects of N application modes on plant height, branch number and pods per plant were not significant. With the increase in N application rates,the seed yield and oil yield of rapeseed were increased significantly and the oil content percent was decreased to some extent, and the increase of N application rates led to an enhancementtrend in erucic acid content, and resulted in a slight decrease in glucosinolate content. But no significant differences in the contents of oil, erucic acid and glucosinolate were observed between the different application modes of N.Yield and N fertilizer contribution rate(NCR) increased with the increase of N application rates(90-270 kg/hm 2 ), but apparently decreased when the N application rate reached to 360 kg/hm 2 . Agronomic efficiency of applied N(AEN),partial factor productivity of applied N(PFPN) and apparent recovery efficiency of applied N(REN) obviously decreased with the increase of N application rates. No significant differences were observed in yield,N fertilizer contribution rate(NCR) and apparent recovery efficiency of applied N(REN) between the rates of N 180 kg /hm 2 and N 270 kg /hm 2 . Agronomic efficiency of applied N(AEN),partial factor productivity of applied N(PFPN) and apparent recovery efficiency of applied N(REN) significantly decreased when the N application rate was more than 270 kg/hm 2 compared with the 90 kg/hm 2 rate. The split nitrogen fertilizer application modes enhanced seed yield or oil yield and the twice of application mode as a basal fertilizer with a top dressing have a higher value under the same N application rate(225 kg/hm 2 ). The values of nitrogen fertilizer use efficiency(AEN,PFPN,NCR,REN) in the treatment with the twice of application mode as a basal fertilizer and a top dressing were relatively higher than those in other N application modes. 【Conclusion】 The rate of N 180 kg/hm 2 and the twice of application mode as a basal with a top dressing are suitable nitrogen fertilization mode under high planting density(36×10 4 plant/hm 2 )and direct-sown rapeseed in moderate soil fertility.

【目的】探讨高密度直播油菜(36×10 4 plant/hm 2 )的合理氮肥管理措施。【方法】2011-2012年油菜季选用甘蓝型油菜品种德油6号,在成都平原稻-油轮作区开展了氮肥施用量、施氮方式对油菜产量、品质和氮肥利用率影响的大田试验。氮肥施用量试验在相同施氮方式(底肥+1次苗期追肥)下设置5个施氮水平(N 0、90、180、270和360 kg/hm 2 ); 施氮方式试验在同等施氮量(N 225 kg/hm 2 )条件下,设置3种施氮方式(一次性底施、底肥+1次苗期追肥、底肥+2次苗期追肥)。【结果】直播油菜农艺性状都随施氮量增多而呈增加趋势,而施氮方式对株高、一次分枝数和单株角果数无显著影响。增施氮肥可显著提高油菜籽粒产量和菜油产量,含油率则有所下降。随施氮量增加,油菜籽芥酸含量呈上升趋势,而硫甙含量略呈降低趋势。施氮方式对油菜籽含油率、芥酸和硫甙含量均无显著影响。油菜产量和氮肥贡献率(NCR)都随施氮量(90~270 kg/hm 2 )加大而提高,当施氮量继续增加(360 kg/hm 2 )时却出现明显下降。但180与270 kg/hm 2 两施氮量处理间的油菜产量、氮肥贡献率(NCR)和氮肥表观利用率(REN)均无显著差异。随施氮量增加,氮肥农学利用率(AEN)、氮肥偏生产力(PFPN)和氮肥表观利用率(REN)表现出明显降低趋势。当施氮量≥270 kg/hm 2 时,氮肥农学利用率(AEN)、氮肥偏生产力(PFPN)和氮肥表观利用率(REN)均显著低于90 kg/hm 2 处理。同等施氮量下,氮肥分期施用可以提高直播油菜籽粒产量和菜油产量,并以底追两次施氮相对较高。底追两次施氮方式的氮肥利用率(AEN、PFPN、NCR、REN)均相对高于其他施氮方式。【结论】在本试验中等肥力条件下,高密度直播油菜(36×10 4 plant/hm 2 )的合理氮肥施用模式为施氮量180 kg/hm 2 和底追两次施氮方式。

Soil organic carbon (SOC) is a key index of soil quality, and it is the basis for the appraisal of role transition of the terrestrial carbon pool between atmospheric carbon dioxide source and sink. The dynamics of bulk density, porosity, silt content, water-holding capacity, soil organic carbon content, light fraction carbon (LF-C) content, heavy fraction carbon (HF-C) content as well as microbial biomass carbon (MBC) content with the restoration of vegetation were investigated, the results showed that: bulk density exponentially decreased with the time extended after being exclosed, while porosity, silt content and water-holding capacity increased with vegetation restoration. Content of SOC, MBC, LF-C, HF-C showed a significant increase with the prolongation of time. The proportion of LF-C increased while the proportion of HF-C deceased gradually after the exclosure. SOC was negatively correlated with bulk density, while positive correlations were found between SOC and other parameters, which suggest the dynamics of SOC is affected by multiple factors.

土壤有机碳是土壤质量的关键指标,也是评估陆地生态系统碳库对大气CO2源、汇效应转变的基础。本文分析了腾格里沙漠南缘植被恢复过程中土壤物理性质、有机碳含量及其组分特征。结果表明:在围封后,土壤容重随着植被恢复年限的延长呈指数级减小,孔隙度、黏粒含量和田间持水量则表现出随年限延长而显著增大的趋势;土壤有机碳、微生物量碳、轻组有机碳和重组有机碳含量随着围封抚育年限的延长而显著增加,轻组有机碳占总有机碳的比例随植被恢复年限的延长而增大,而重组碳所占比例则随时间变化显著下降。土壤有机碳与容重呈显著负相关,而与其他参数呈显著正相关,说明其变化受多种因素影响,且对土壤物理性质的变化有重要意义。

本文分析了1961-1965年、1981-1985年及2004-2006年3个时期我国冬油菜种植区的土壤肥力状况，氮、磷、钾及硼肥的施用效果，氮、磷、钾肥的农学效率及肥料贡献率。结果表明，与20世纪60年代相比，近期油菜主产区耕地土壤有机质、全氮、碱解氮、速效磷及有效硼含量大幅度上升；土壤有机质、速效磷及有效硼含量较80年代也略有增加。但由于土壤养分临界值水平的提高，近期土壤有效氮、磷、钾、硼的缺乏范围存在扩大趋势。田间肥效试验结果表明，以增产量为标准，近期油菜施用氮、磷、钾、硼油菜籽增产高于其它两个时期。施肥在油菜籽产量中的贡献率从1961-1965年间的23.8%和1981-1985年间的54.5%增长到2004-2006年间的55.1%。总体上，我国冬油菜种植区土壤养分肥力稳中有升，但速效养分相对缺乏面积扩大；施肥对油菜籽单产的贡献率增大，油菜丰产必须建立在科学施肥的基础上。

 Rapeseed yield from main inflorescence under direct-seeding (high density) pattern makes great contribution to all plant yield. To promote main inflorescence yield, field experiment was conducted to research nitrogen (N) application effects, source-sink relationship and grain-filling process. The main infloresence of Brassica napus cv Huayouza 9 was divided into 3 parts (up, middle and bottom) according to 3 flowering periods (final flowering, nourishing flowering and early blooming). Results showed that N application improved seed yield significantly in these 3 parts. The corresponding increases were 73.3%, 138.3% and 108.6% respectively. Yield improvement was mainly resulted from more siliques in all 3 parts (53.4%, 37.9% and 25.2% more siliques respectively). 1 000-seed weight of middle part was improved, and seeds per silique on upper part was increased. On up and bottom parts, N treatment resulted in higher dry matters of silique shell and larger seed-to-shell ratio, which indicated that N accelerated material and energy transport from silique wall to seeds. N application also resulted in longer periods and more rapid dry matters and N accumulation in seeds. Duration of grain-fulling was important to silique numbers and seeds per silique. 1 000-seed weight was closely related to dry matter accumulation rate. Therefore, under direct-seeding high density pattern, N fertilization could improve source-sink relationship, accelerate grain-filling process, and further increase rapeseed yield.

直播（密植）油菜主序籽粒对全田产量贡献率大。为充分发挥主序增产潜力，通过对大田直播油菜（甘蓝型油菜品种华油杂9号）进行施氮处理，将主序角果按形成时期（终花期、盛花期和始花期）分为上部、中部和下部角果，从产量构成因子、库源关系以及籽粒充实过程三个方面分析施氮对油菜主序不同部位的增产效果。结果表明，施氮可显著提升主序各部位的籽粒产量，与不施氮处理相比，施氮处理油菜主序上部、中部和下部角果籽粒的产量分别增加了73.3%、138.3%和108.6%。角果数的增多是增产的主要原因，主序各部位角果数分别增加了53.4%、37.9%和25.2%，同时氮肥施用提高了中部角果的千粒重和上部角果的每角粒数。氮肥的投入增大了上部和下部角果皮的干物质重和粒壳比，促进了角果皮干物质向籽粒的转移。与不施氮处理相比，籽粒干物质和氮素积累的持续时间和速率明显提高。籽粒干物质充实的持续时间是决定油菜角果数和每角粒数重要因素，而籽粒的千粒重则和干物质积累速率密切相关。因此可通过氮肥施用改善油菜后期各部位的源库关系，促进籽粒的充实进程，进而增加油菜的籽粒产量。

To enhance the research of mechanized operation for rapeseed, and understand the Yangyou NO. 6 suitable for mechanized operation, Field experiment were conducted on the sowing-date research of different varieties and density research of Yangyou No.6 under the different sowing-dates. Results showed that Yangyou No.6 had a higher output level and stronger ability to tolerate later sowing, and they all could have higher yield sowing before Oct.23. Under the condition of the different sowing-dates, the density had greater influence on Yangyou No.6's output. With the postponement of sowing-date, higher density (60×104plants/hm2、75×104plants/hm2)had better compensation function to output level of Yangyou No.6. Meanwhile, with improvement of density, some properties as shoot height, stem thickness were too obviously dropping, and more benefit to harvest by machine. From the experiments, Yangyou No.6 have better suitable for mechanized operation.

为了促进油菜生产的全程机械化作业研究，明确扬油6号对机械化作业的适应性，组织了不同品种的播期试验和扬油6号不同播期下的密度试验，结果表明扬油6号具有较高的产量水平和较强的耐迟播能力，在10月23日以前播种均能获得较高的产量水平。在不同播期条件下，密度对扬油6号产量有较大的影响。随着播期的推迟，较高的密度（60万株/hm2、75万株/hm2）对扬油6号的产量水平较好的补偿作用。同时，随着的密度的提高，株高、茎粗等性状也明显下降，更利于机械收割。说明扬油6号对机械化作业有较好的适应性。

For rapeseed mechanization production, effects of rape density and nitrogen (N) application rate on growth and N use efficiency were investigated under field condition. Two planting density (15?104 and 45?104 plant per hectare) and four N rates (0, 90, 180 and 270kg per hectare) were applied to study the interaction between N and density on agronomic characteristics, yield, N use efficiency and N fertilizer requirements for Zhongshuang 11. Results showed that plant height, branch number, effective siliques per plant and seeds per pod significantly decreased at higher density, but branch height and 1 000-seeds weight increased significantly. Under higher density, the plant-type was uniform and ideal for mechanized harvesting. Yield of high density rape was higher. Both yields on high and low density increased at 0 to 180kg/hm2 N rates. But when N rates were up to 270kg/hm2, both yields decreased. N use efficiency decreased at higher N rates and lower density. It indicated that higher density could promote seed N accumulation, decrease N fertilizer requirement and improve the N use efficiency. For the same targets yield (compared to the top economic yield at low density, the average yield of Hubei Province and that of China), the N fertilizer requirement significantly decreased by 22.9% to 30.6% after increasing planting density. Key words: Rapeseed (Brassica napus L.); Planting density; Nitrogen fertilizer; Yield; Nitrogen use efficiency

 为机械化种植油菜，研究不同施氮水平下密度对直播油菜生长发育和氮肥利用效率的影响。以甘蓝型油菜品种中双11号为材料，在低密（15万株/hm2）和高密（45万株/hm2）两种密度下，设施氮0、90、180和270kg/hm2处理，分析施氮量与密度对油菜农学性状、产量、氮肥利用效率的影响，并对比分析了密度与油菜需氮量之间的关系。结果表明，增密后油菜的株高、分枝数、单株角果数和每角粒数显著降低，分枝高度和千粒重显著增加。高密油菜群体株型结构整齐均一，更能满足机械化收获需要。高密处理油菜籽粒产量高于低密处理。施氮0～180kg/hm2时，两个密度下的籽粒产量均随施氮量增加而显著提高，但在270kg/hm2时两密度下油菜产量均有所下降。油菜氮肥表观利用率随着施氮量的增加而下降，但是又随种植密度的增加而增加。说明增加密度能促进氮素向油菜籽粒转移，降低每生产100kg籽粒油菜需氮量，提高氮肥表观利用率。在相同的目标产量（低密下的经济产量、湖北省油菜平均单产和全国油菜平均单产）下，油菜增密后可以节约氮肥用量22.9%~30.6%，增密减氮效果明显。  

【Objective】This study investigated the effects of different dosage of special controlled release urea (CRU) on the yield and nitrogen (N) uptake of winter oilseed rape in different areas. Our aim was to evaluate the suitable rate of the special CRU for oilseed rape and provide the basis for guiding light simplification of oilseed rape production.【Method】Field experiments were conducted in Hengyang (Hunan Province), Jiujiang (Jiangxi Province), and Wuxue (Hubei Province) during the period of 2015-2016, investigating nutrient release and fertilization effects of the special CRU. Each site included 5 nitrogen application rates being 0, 60, 120, 180 and 240 kg N·hm -2 , respectively.【Result】Field bagging experiment showed that the release time of special CRU was about 150 days, with the accumulative release amount of 83.4%, which coincided with the N demand of oilseed rape. The application of special CRU could control the harvest density of winter rapeseed, increasing the number of pods per plant and seed number per pod. Compared with no N treatment, the number of pods per plant and seed number per pod increased 15.0-81.5 pods per plant and 0.2-2.4 seeds per pod, respectively. Harvest density changed the coordination group and individual with N fertilizer variation. Oilseed rape production performed the highest grain yield when applying 180 kg N·hm -2 among the sites, which increased by 1 118 and 1 088 and 2 049 kg·hm -2 , Compared with the without N treatment, respectively. By fitted with linear and platform model, optimal special CRU dosages were 174, 180 and 192 kg N·hm -2 in Hengyang, Jiujiang and Wuxue, respectively. The biomass, N concentration and N accumulation of aboveground biomass were significantly increased with the application of the special CRU. With the increase of N application rate, the proportion of N in the stem was raised gradually, and the proportion and distribution of N in the seed decreased, while the ratio of N distribution in the shell kept about 10%. The nitrogen use efficiency (NUE) was different in different periods. The NUE was 50.69%-56.89% at flowering period, 39.39%-46.71% at harvested period, and only 9.20%-23.45% at seedling stage, respectively. At seedling and flowering stages, the NUE showed increase first and then decrease with N application rate increase, reaching the maximum when the amount of the special CRU dosage was 180 kg N·hm -2 . However, at harvest stage, the NUE reduced with the increase amount of nitrogen application. 【Conclusion】The special CRU for winter oilseed rape could improve N uptake and promote the growth and development of rape in each growth period, especially in regulating the harvesting density, increasing the pod number per plant and seed number per pod, and eventually enhancing the rapeseed yield. The recommended amount of special CRU was 180 kg N·hm -2 among the sites.

【目的】明确不同冬油菜种植区域油菜专用控释尿素用量对冬油菜产量和氮素吸收的影响,验证油菜专用控释尿素一次性施用的可行性和适宜用量,为指导冬油菜轻简化生产提供依据。【方法】于2015—2016年分别开展油菜专用控释尿素静水释放试验和田间埋袋养分释放以及控释尿素用量施用效果田间试验。油菜专用控释尿素用量试验布置于冬油菜3个主产地区——湖南衡阳、江西九江和湖北武穴。试验共设5个氮肥用量梯度,分别为0、60、120、180和240 kg N·hm -2 ,探究油菜专用控释尿素对不同区域冬油菜产量和氮素吸收的影响。【结果】田间埋袋试验结果表明,油菜专用控释尿素的缓释期在150 d左右,累积释放量为83.4%,与冬油菜氮素需求吻合。施用油菜专用控释尿素可以调控收获密度,增加冬油菜的单株角果数和每角粒数。与不施氮处理相比,单株角果数、每角粒数分别增加15.0—81.5角/株和0.2—2.4粒/角,收获密度随氮肥用量增加或降低协调群体与个体。3个产地的籽粒产量均在施氮量达到180 kg N·hm -2 时最高,分别较不施氮增产1 118、1 088和2 049 kg·hm -2 。用线性加平台模型拟合的最佳控释尿素用量,湖南衡阳、江西九江和湖北武穴分别为174、180和192 kg N·hm -2 。油菜专用控释尿素施用显著增加地上部生物量、氮素含量和氮素积累量。在收获期时,随氮肥用量增加,茎秆中的氮素分配比例逐渐增加,籽粒中氮素积累分配比例减小,而角壳的氮素分配比例保持在10%左右。不同时期氮肥利用率存在差异,苗期最小,花期最大,收获期居中,分别为19.20%—23.45%、50.69%—56.89%和39.39%—46.71%。苗期和花期的氮肥利用率随着施氮量的增加,出现先增加后降低的趋势,在控释尿素用量为180 kg N·hm -2 时达到最大；收获期的氮肥利用率随着施氮量的增加呈降低趋势。【结论】油菜专用控释尿素一次性施用可以增加油菜各生育时期的氮素吸收、促进油菜生长发育,提高收获密度、单株角果数和每角粒数,增加油菜产量。不同冬油菜主产区所需专用控释尿素推荐用量差异不大,平均为180 kg N·hm -2 。

The directsowing cultivation has played an important role in increasing planting areas and total production of oilseed rape in China. However, the lagging cultivation and fertilization techniques restrict greatly rapeseed yield and fertilizer use efficiency. Two field experiments were therefore conducted in the main oilseed rape planting areas of Hubei province during 2009/2010. The objective of this study is to investigate the effects of different cultivation patterns on growth, seed yield, economic benefit, nutrient uptake and fertilizer use efficiency of direct sowing oilseed rape, and thereby to summarize the key techniques of high yield and high efficiency cultivation under current production conditions. The results show that the optimized cultivation pattern (OCP) has higher rapeseed yield than that of the farmer’s practice pattern (FFP), and the best performance is observed in the OCP Ⅲ treatment. With this cultivation pattern, reasonable fertilization measures (N 195 kg/ha, P 2 O 5 90 kg/ha, K 2 O 90 kg/ha and Broax 15 kg/ha were applied, and N and K fertilizers were applied in splits) are implemented on the basis of increasing appropriately plant density (30×10 4 plant/ha), using straw returning and enhancing plant protection to pest, disease and weed. The rapeseed yield and net benefit are increased by 35.9 % and 1632 Yuan/ha in the OCP Ⅲ treatment compared with the FFP treatment. In addition, the aboveground dry matter and nutrient accumulation amounts in the OCP Ⅲ are also significantly improved, and the mean N and K fertilizer efficiencies (PFP) are N 13.7 kg/kg and K 2 O 29.8 kg/kg, respectively. Hence, the OCP Ⅲ is considered as a better practice to achieve high yield and high efficiency of directsowing oilseed rape in present research. The results from this study indicate that cultivation management should be accord with the growth process and nutrient uptake regulation of directsowing oilseed rape. With this principle, we should increase appropriately planting density to enlarge source and sink of oilseed rape, whilst enhance plant protection to control pest, disease and weed. And more importantly, optimal fertilization measures should be used, including balanced fertilization, applying inorganic fertilizer combined with organic manure, and reasonably arranged fertilization time and ratio.

发展直播油菜对增加我国油菜种植面积和总产有重要意义，但栽培措施尤其是施肥技术的滞后极大地影响了油菜的产量及施肥效果。2009/2010年度在湖北省油菜主产区设置田间试验，研究栽培模式对直播油菜生长、产量、经济效益和养分吸收利用的影响，探讨适合当前生产的高产高效栽培技术。结果表明，各优化模式比农民习惯栽培模式均有增产增收效果，其中在30×10 4 plant/hm 2 种植密度、秸秆还田和加强病虫草害防治的基础上进行优化施肥（氮、磷、钾肥用量分别为N 195 kg/hm 2 、 P 2 O 5 90 kg/hm 2 、K 2 O 90 kg/hm 2 ，硼砂用量15 kg/hm 2 ，氮肥和钾肥分次施用）的模式Ⅲ表现最好，比农民习惯施肥增产35.9 %、增收1632 Yuan/hm 2 ，地上部干物质量和养分累积也均较高，氮、钾肥偏生产力分别为N 13.7 kg/kg和K 2 O 29.8 kg/kg，实现高产高效目标。说明当前直播油菜的栽培模式应结合其生长发育进程和养分吸收规律，适当密植以增库促源，加强植保防治病虫草害，更重要的是积极推行平衡施肥和有机、无机配施，并合理安排施肥时期及比例。

【Objective】 To optimize fertilization strategy further in the rice-oilseed rape rotation system, the effects of N fertilizer application on crop yield, N uptake, N use efficiency and the residual effects of N fertilizer applied in rice season were studied in the annual rotation system. Meanwhile, the economical benefit with different N fertilizer treatments in the rice-oilseed rape rotation system were estimated. 【Method】A field experiment, to study crop yield, N uptake, N use efficiency, the residual effects of N fertilizer and economical benefit in the rice-oilseed rape rotation system were conducted in Honghu county, Hubei province from May 2010 to May 2011. Different N application rate treatments was included in the rice season. While in the oilseed rape season the original treatment in the rice season was split into with and without N application sub-treatments. 【Result】 Due to the different application rate and allocations of N fertilizer, the differences among the yield, N use efficiency and economical benefit were significant. In rice season, the yield and N use efficiency were the highest when N application rate was 165 kg N•hm-2. The residual effects of N fertilizer applied in rice season were significant, which could improve the yield of oilseed rape, ranging from 107 to 644 kg•hm-2. The N uptake of oilseed rape also increased significantly, from 3.9 to 35.2 kg N•hm-2. The residual effects of N fertilizer were equivalent to 5-33 kg N•hm-2 N fertilizer applied in the oilseed rape season. The residual effects were positively correlated with N application rate. Nevertheless, in the rice season excessive N fertilizer application rate would decrease the rice yield, N use efficiency and economical benefit. Overall the economical benefit was the largest when both N application rate in rice and oilseed rape season were 165 kg•hm-2. 【Conclusion】Reasonable N fertilization could significantly increase yield of rice and oilseed rape. N application in rice season had a significant residual effect. Therefore, optimum N fertilization management in oilseed rape season should consider the residual effect of N application in rice season.

【目的】从周年轮作的角度分析了氮肥施用对水稻-油菜轮作体系中作物产量、氮素吸收量、肥料利用率的影响以及水稻季施用氮肥在油菜季的后效特点，比较和明确不同施肥处理下水稻-油菜轮作体系经济效益的差异。【方法】2010—2011年在湖北省洪湖市布置前茬水稻不同氮肥用量以及后茬油菜裂区施氮和不施氮两个副区的田间试验，研究了不同施氮条件下水稻和油菜的产量、氮素吸收量和氮肥利用率。根据试验结果分析稻油轮作系统氮肥后效及经济效应。【结果】由于氮肥用量和分配的不同，作物产量、氮肥利用率和经济效应表现出明显地差异，水稻季施氮165 kgN•hm-2产量最高，氮肥利用率最大；水稻季施用的氮肥具有明显的后效，显著增加油菜产量107—644 kg•hm-2，氮素吸收量增加3.9—35.2 kg•hm-2，相当于油菜季施氮5—33 kgN•hm-2的增产效果。氮肥的后效与施氮量成正比，虽然水稻季高氮处理增加氮肥后效，但是降低了水稻产量、当季氮肥利用率以及经济效益。本试验条件下，水稻季和油菜季施氮量均为165 kgN•hm-2时，经济效益最高。【结论】合理的氮肥施用能明显提高水稻和油菜的产量，在整个周年水旱轮作中水稻季氮肥具有一定的后效，油菜生长季应该在充分考虑前茬水稻氮肥后效的基础上进行优化推荐施用。

The effects of application amounts of nitrogen, phosphate and potassium and planting density on yield and quality of rape cultivar, Huayouza 9, under the fixed N: P2O5: K2O ratio (1: 0.55: 0.8) conditions of different nitrogen levels (135, 225 and 315 kg/ha) and planting densities (15×104, 45×104 and 75×104 plant/ha). The results show that yields of rapeseed are increased with the increases of fertilizer and density, and the influences of fertilizer levels on the increased yield rates are more effective than those of the densities. The increases of densities under the low fertilizer level have significant effect on the increased yields. There are great differences on main economic characters and yield when the fertilizer level and density are changed. However, the density has more influence on the number of the effective branches and pods. When the increased density by 30×104 plant/ha, the number of effective branches is reduced 1.7–3.8 per plant. The oil content of rapeseed of main stem is higher than that of branches, while the contents of protein and glucosinolate are lower in the main stems. There would be a fall in the content of oil and an increase of protein and glucosinolate in rapeseed when the amount of fertilizer is raised, while when the density is increased, there would be an increase in oil content and falls in the contents of protein and glucosinolate of main stem and branches, and a fall in the glucosinolate content of the whole plant. Considering reducing fertilizer application, saving cost and increase efficiency, the optimum levels of N, P2O5 and K2O application for Huayouza 9 are 135–225 kg/ha, 75–124 kg/ha and 108–180 kg/ha respectively, and density is increased appropriately in the range of 45×104–75×104 plant/ha in order to obtain seed yield more than 3000kg/ha.