冬油菜氮素营养调控技术及相关机制研究

发布时间：2018-01-18 00:34

本文关键词：冬油菜氮素营养调控技术及相关机制研究　出处：《华中农业大学》2016年博士论文　论文类型：学位论文

【摘要】：油菜是我国重要的油料作物,长江流域是我国最大的冬油菜种植区,其种植面积和总产占全国90%左右,该区域油菜生产对保障我国食用油安全具有重要意义。冬油菜氮肥需求量大,实际生产中氮肥过量或不足现象同时存在、运筹不合理、种类结构单一、施用方式粗放等现象均很普遍。氮肥不合理施用造成了油菜产量潜力得不到充分发挥,氮肥利用率降低等一系列影响油菜高产高效的问题。为此本研究选取长江流域冬油菜主产区开展冬油菜氮肥多年多点田间试验,通过研究和比较不同生产场景下氮肥用量、运筹、种类、施用方式以及根层土壤氮素调控等技术措施,从冬油菜产量和产量构成因素、干物质累积和氮素吸收以及氮肥利用效率角度剖析合理氮肥施用对冬油菜产量形成和氮素吸收利用的机制,以期为建立冬油菜氮素管理策略提供科学依据。主要研究结果如下:(1)根据栽培模式、轮作方式、种植密度、生态条件等进行合理氮肥用量的精准调控。栽培模式导致冬油菜对氮肥的响应不同。移栽冬油菜产量水平明显高于直播冬油菜,平均增产15.3%,较高单位面积角果数是移栽油菜获得高产的重要保障,移栽冬油菜单位面积角果数比直播冬油菜多178.9个/m2。施氮显著提高了移栽和直播冬油菜干物质和氮素累积量,尤其是蕾薹期后增幅明显,相比不施氮处理,直播冬油菜平均增产率和氮素累积量增幅分别为255.9%和279.1%,明显高于移栽冬油菜。直播冬油菜氮肥农学利用率也高于移栽冬油菜,说明直播冬油菜对氮肥响应更为敏感。目标产量为1000~2000 kg/hm2时,移栽和直播冬油菜氮肥推荐用量分别为151.5 kg/hm2和149.0 kg/hm2;目标产量为2000~3000 kg/hm2时,移栽和直播冬油菜氮肥推荐用量分别为208.3 kg/hm2和214.7 kg/hm2。相同产量水平下,移栽冬油菜比直播冬油菜节约氮肥35.7 kg/hm2。不同轮作模式下土壤供氮能力的差异影响冬油菜施氮效果和适宜施氮水平。棉花-油菜轮作油菜产量显著高于水稻-油菜轮作,平均增产27.9%。不施氮处理下水稻-油菜轮作油菜产量显著低于棉花-油菜轮作,说明棉花-油菜轮作土壤供氮能力明显高于水稻-油菜轮作。水稻-油菜轮作平均增产率和农学效率分别为84.0%和6.0 kg/kg,显著高于棉花-油菜轮作,说明水稻-油菜轮作冬油菜产量对氮肥依赖性更大。氮肥施用在轮作体系中发挥着重要作用,适当增加氮肥可以弥补水稻-油菜轮作的供氮不足,缩小两种轮作模式的产量差。水稻-油菜冬油菜适宜氮肥用量为210.8 kg/hm2,而相同产量水平下,棉花-油菜轮作可以节约氮肥56.3 kg/hm2。栽培密度与氮肥显著影响了冬油菜产量及产量构成因素。优化栽培密度是获得高产的前提,高密度可以影响个体干物质积累并减少了单株角果数,施氮能够提高单株角果数从而增加产量。低密度条件下,冬油菜产量随着氮肥用量的增加而增加;高密度条件下,过量氮肥投入对产量并无显著影响。目标产量为3000kg/hm2时,区域移栽冬油菜常规栽培密度为9.0×104株/hm2,如果密度可以增加到10.0~12.0×104株/hm2,最佳施氮量可降低10.3%~23.7%;相反,当密度降低到7.0~8.0×104株/hm2时,适当增加氮肥供应13.9%~34.8%可以获得目标产量。苗期渍水对油菜产量形成的抑制作用以及氮肥对受渍冬油菜生长的缓解效应。苗期渍水明显抑制了冬油菜生长,叶片数、叶面积和SPAD值均有不同程度下降,渍水减少了油菜干物质累积和氮素吸收利用,对油菜生长造成了不可恢复的影响。苗期渍水处理显著降低了油菜产量,减产达23.6%,成苗密度和单株角果数下降是引起产量降低的重要原因,分别下降了7.6%和20.4%。氮肥施用促进了油菜生长发育,改善了群体质量,缓解了苗期渍水造成的产量损失,并且缓解效应与氮肥投入量存在直接关系,合理增施氮肥对苗期渍水油菜生长恢复具有很好的补偿效应。在保证产量不下降的情况下,排水处理要比渍水处理节约氮肥59.2 kg/hm2。(2)根据栽培模式和土壤供氮能力进行合理的氮肥运筹。与氮肥全部基施相比,移栽冬油菜氮肥60%基施、40%作越冬肥追施;直播冬油菜氮肥60%基施、20%作苗肥、20%作越冬肥追施效果最好,增加了油菜产量,提高了氮肥利用率。其中,产量增幅分别为14.7%和21.7%,氮素累积量增幅分别为19.8%和27.8%。各试验点氮肥运筹效果表现出的差异主要取决于土壤供氮能力。(3)控释尿素施用为氮肥一次性施用和减少氮肥施用提供了可行性,而控释尿素与普通尿素配施进一步降低了油菜生产成本。与普通尿素相比,移栽和直播冬油菜控释尿素平均增产率分别为7.4%和11.5%,控释尿素在低氮(90 kg/hm2)水平上的增产效果好于中高氮水平,说明控释尿素减量施用具有可行性。低氮水平条件下控释尿素增产原因主要是依赖于花后干物质和氮素累积量的显著增加,随着氮肥用量增加,控释尿素相比普通尿素增产率是逐渐降低的,其中,控释尿素施氮180 kg/hm2既能够获得较高产量又可进一步降低氮肥用量。控释尿素和普通尿素配施不仅可以减少生产成本,还可以通过适宜配施比例协调土壤、肥料氮素供应和冬油菜氮素需求,进而增加产量,提高氮肥利用率。基于产量和控释尿素与普通尿素配施比例存在的线性加平台关系,等氮量条件下,移栽冬油菜控释尿素与普通尿素最佳配施比例为42%控释尿素和58%普通尿素;直播冬油菜为60%控释尿素和40%普通尿素。(4)根据栽培模式和土壤供氮能力确定合理氮肥施用方式。施氮方式对油菜产量、氮素吸收和利用率产生了显著影响,施肥效果总体表现为氮肥集中施用翻施表施的趋势。与表施处理相比,移栽和直播冬油菜氮肥集中施用产量平均增幅分别为18.2%和23.8%。集中施用处理可以明显提高两种栽培模式冬油菜干物质累积,尤其是促进了花后地下部干物质和地上部干物质同步累积,从而提高油菜产量。结合冬油菜栽培模式,实际生产中移栽和直播冬油菜应该分别采取穴施或条施的氮肥集中施用技术。(5)基于土壤Nmin测试根层氮素管理可以有效匹配土壤氮素供应和冬油菜氮素吸收。基于两季研究结果,利用对数函数描述土壤氮素供应和冬油菜相对氮素吸收量之间的关系,可以得出移栽到越冬期、越冬期到蕾薹期、蕾薹期到花期、花期到成熟期的最佳氮素供应目标值分别为105~128,95~105、94~102和71~73kg N/hm2,根层氮素管理在温暖冬季或者正常气候条件下相比经验氮肥管理效果会更好。
[Abstract]:Rape is an important oil crop in China, the Yangtze River Basin is China's largest winter rapeseed planting area, its planting area and total output accounted for about 90% of the country, has important significance in the area of rapeseed production of edible oil safety to protect our country. Nitrogen fertilizer demand of winter rapeseed, the actual production of nitrogen fertilizer and the phenomenon of excessive or insufficient there is, or is not reasonable, such as single species structure, extensive application phenomena are very common. Unreasonable application of nitrogen was caused by the rape yield potential can not be brought into full play, reduce the utilization rate of nitrogen fertilizer and a series of high yield of rapeseed in question. This study selects the rapeseed zone of Yangtze River basin to carry out winter winter rapeseed n years multiple field trials, through research and comparison of different production scenarios of nitrogen fertilizer dosage, application, type, application method and root layer soil nitrogen regulation measures from winter rapeseed yield and yield. Factors, dry matter accumulation and nitrogen absorption and nitrogen utilization efficiency of nitrogen fertilizer use the perspective of reasonable mechanism of absorption and nitrogen of winter rapeseed yield, in order to provide scientific basis for the establishment of winter rape nitrogen management strategies. The main results are as follows: (1) according to the pattern of cultivation, rotation, planting density, ecological conditions etc. for accurate regulation of nitrogen fertilizer. The reasonable cultivation patterns of winter rape response to nitrogen fertilizer resulted in different transplanting. Winter rapeseed yield was significantly higher than that of direct seeding of winter rapeseed, with an average increase of 15.3%, higher pod number in unit area is an important guarantee of transplanting rape yield, pod number per unit area of transplanting winter rape 178.9 more /m2. than direct seeding of winter rape fertilizer nitrogen significantly increased the transplanting and direct sowing of winter rapeseed dry matter and nitrogen accumulation, especially after the bud period increased significantly, compared with the treatment without nitrogen application, direct sowing of Winter Rape Yield rate and nitrogen accumulation rate were 255.9% and 279.1%, significantly higher than winter transplanting rapeseed. Live nitrogen of winter rapeseed agronomic rate is also higher than that of winter rape transplanting, live winter rape was more sensitive to nitrogen response. The target yield of 1000~2000 kg/hm2, transplanting and direct sowing of winter rape nitrogen fertilizer recommended dosage were 151.5 kg/hm2 and 149 kg/hm2 2000~3000 kg/hm2; the target yield, transplanting and direct sowing of winter rape nitrogen fertilizer recommended dosage were 208.3 kg/hm2 and 214.7 kg/hm2. in the same level of yield, influence ability of nitrogen of winter rape transplanting than soil conservation of winter rape live n 35.7 kg/hm2. under different rotation systems for the winter rape nitrogen effect and suitable nitrogen level. Cotton the yield of rapeseed rotation was significantly higher than that of rape - rice rapeseed rotation, the average yield of 27.9%. treatment without nitrogen application under rice rape rotation was significantly lower than that of cotton yield of rape Flower - rape rotation, cotton canola rotation that soil nitrogen supply capacity was significantly higher than that of rice rape cropping rice rapeseed rotation. The average rate of increasing yield and agronomic efficiency were 84% and 6 kg/kg, significantly higher than that of cotton canola rotation, rice rape cropping winter rapeseed yield more dependent on nitrogen fertilizer nitrogen fertilizer plays. An important role in the rotation system, nitrogen supply increasing nitrogen can compensate for the rotation of rice and rape, reduce the two rotation mode. The yield of rice and rape winter rape appropriate nitrogen amount was 210.8 kg/hm2, and the same level of yield, cotton canola rotation can save 56.3 kg/hm2. planting density and N fertilizer significantly affected factors of winter rapeseed yield and yield. The optimum cultivation density is high yield condition, high density can dry matter accumulation and reduced the number of pods per plant nitrogen can influence the individual. Increase the number of pods per plant and increase the yield. Under the condition of low density, yield of winter rape increased with the increase of nitrogen fertilizer; high density conditions, excessive N fertilizer yield had no significant impact on the target. The yield is 3000kg/hm2, area of winter rape transplanting conventional planting density of 9 * 104 strains of /hm2, if the density can be increased to 10.0~12.0 * 104 strains of /hm2, the best nitrogen can reduce the amount of 10.3%~23.7%; on the contrary, when the density is reduced to 7.0~8.0 * 104 /hm2 strains, increasing nitrogen supply 13.9%~34.8% can obtain the target yield. Inhibition of waterlogging at Seedling Stage on Rape Yield Formation and nitrogen fertilizer on mitigating the effects of waterlogging growth of winter rapeseed. Waterlogging significantly inhibited the winter rape at seedling stage growth, leaf number, leaf area and SPAD value were decreased, waterlogging reduced dry matter accumulation and nitrogen uptake and utilization of rapeseed, rape growth caused unrecoverable The effects of waterlogging at seedling stage. Significantly decreased the yield of rapeseed, yield up to 23.6%, seedling density decreased and the number of pods per plant is an important cause of reduced production, dropped 7.6% and 20.4%. respectively. Nitrogen fertilizer promoted the growth and development of rape, improve population quality, alleviate the yield loss caused by waterlogging at seedling stage, and there are direct relief the relationship between effect and N inputs, reasonable nitrogen recovery has a good compensation effect of waterlogging at seedling stage. Rape growth in ensuring the yield decline, water treatment than saving waterlogging treatment of nitrogenous fertilizer is 59.2 kg/hm2. (2) of nitrogen fertilizer reasonably according to the cultivation mode and soil nitrogen supply capacity. Compared with the total nitrogen the base fertilizer, transplanting winter rape nitrogen 60% base fertilizer, 40% more fertilizer topdressing nitrogen fertilizer; winter rape 60% live 20% as base fertilizer, fertilizer for 20% more fertilizer topdressing increased rapeseed yield had the best effect. The amount, improve the utilization rate of nitrogen fertilizer. The yield increase by 14.7% and 21.7%, nitrogen accumulation rate were between 19.8% and 27.8%. of each test point showed nitrogen fertilizer effect mainly depends on the soil nitrogen supplying capacity. (3) controlled-release urea application provides the feasibility of nitrogen fertilizer application and nitrogen fertilizer to reduce disposable. The controlled-release urea combined with conventional urea to further reduce the rape production cost. Compared with urea, transplanting and direct sowing of winter rapeseed controlled-release urea average production rates were 7.4% and 11.5%, controlled release urea at low nitrogen level (90 kg/hm2) on the yield increasing effect was better than that in high nitrogen level, controlledrelease urea reducing the application is feasible. Under the low nitrogen level of controlled-release urea yield is the main reason depends on the significant increase after anthesis dry matter and nitrogen accumulation, the nitrogen fertilizer increased, compared with common urea controlled release urea The rate is gradually reduced, the controlled-release urea nitrogen 180 kg/hm2 can obtain higher yield and can further reduce the amount of nitrogen fertilizer, controlled release urea and common urea fertilizer can not only reduce the production cost, but also through the appropriate fertilizer proportion of soil fertilizer, nitrogen supply and winter rape nitrogen demand, and increase the yield. To improve the utilization rate of nitrogen fertilizer. The relationship between yield and linear plus platform of controlled-release urea and conventional urea fertilizer are based on the proportion of nitrogen, under the condition of transplanting rapeseed controlled-release urea and conventional urea fertilizer optimum ratio of 42% controlled-release urea and 58% urea; live winter rapeseed controlled release urea and common urea 40% 60%. (4) according to the reasonable nitrogen fertilization for determining nitrogen cultivation pattern and soil. Nitrogen application on yield, nitrogen absorption and utilization rate had a significant impact in the overall performance in nitrogen fertilization effect Application of double surface trend. Compared with the application of surface treatment, transplanting and direct sowing of winter rape nitrogen application yield average increase of 18.2% and 23.8%. concentration treatment can significantly improve the dry matter accumulation of two kinds of cultivation patterns of winter rapeseed, especially after flowering promoted root dry matter weight and shoot dry matter accumulation and synchronization. To improve the yield of rapeseed. Combined with the winter rapeseed cultivation mode, the actual production of transplanting and direct sowing of winter rapeseed should adopt when nitrogen application or banding technique. (5) soil test Nmin root zone nitrogen management can effectively match the supply of soil nitrogen and nitrogen uptake of winter rapeseed. Based on the two quarter results based on using logarithmic function description the relationship between soil nitrogen supply and winter rape relative nitrogen absorption, it can be transplanted to the winter, winter to bud stage, bud stage to flowering, flowering into The optimal nitrogen supply target value is 105~128,95~105,94~102 and 71~73kg N/hm2 respectively. The nitrogen management in root zone is better than that in normal climate.

【学位授予单位】：华中农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S565.4

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