冬小麦贮墒旱作产量形成与水氮利用特征

发布时间：2017-12-30 20:06

本文关键词：冬小麦贮墒旱作产量形成与水氮利用特征　出处：《中国农业大学》2017年博士论文　论文类型：学位论文

【摘要】：在华北水资源限制地区,减少冬小麦灌溉对降低地下水超采具有重要意义。现行推广的小麦节水栽培技术春季灌溉1-2次(春灌量75-150 mm),为进一步减少灌溉量,我们提出了"贮墒旱作"栽培模式,即播前贮足底墒、生育期内不再灌溉。目前这一模式的技术已开始示范应用,但对其产量形成和水氮利用特点及机理尚需要深入探明。本研究在河北地下水超采区冬小麦-夏玉米两熟种植体系下,通过设置冬小麦贮墒旱作和节水灌溉(春灌2水)两种模式的比较试验以及不同播前贮墒量、施氮量和不同品种对贮墒旱作的影响等试验,系统考察了贮墒旱作栽培的群体动态、源库性能、产量构成、耗水规律、氮素利用等特征,综合分析了其产量、效率和效益潜力。主要结果如下:(1)贮墒旱作模式的冬小麦产量低于春灌2水模式,主要是降低了群体总粒数和生物产量,但花前贮藏物质转运及其对籽粒贡献率明显增加、千粒重提高,仍可获得6500 kg hm-2以上产量水平,冬小麦-夏玉米全年贮墒旱作产量达17000 kg hm-2以上。连续3年贮墒旱作冬小麦产量为6694-7432 kg·hm-2,平均产量比春灌2水模式减少16.6%。春季不灌溉降低了茎蘖成穗率,导致穗数减少;降低了开花期生物量,导致穗粒数减少;缩小了个体株型,降低了群体叶面积指数。但提高了群体穗叶比和粒叶比,库/源比值增大,促进了花前营养器官中存储物质向籽粒的转运,提高了籽粒灌浆速度,使千粒重明显增加。在周年冬小麦-夏玉米两熟种植体系中,冬小麦贮墒旱作的开花和成熟期提早,让出5-7天光温资源给夏玉米,有利于玉米稳产增产,使全年产量维持丰产水平。通过增加基本苗以增加穗数,贮墒旱作小麦的产量可进一步增加。(2)贮墒旱作冬小麦免去了生育期灌溉,显著降低总耗水量,麦收后腾出了较大土壤库容存储夏季降水,提高了周年水分利用效率。贮墒旱作冬小麦耗水来源是生育期降水和土壤贮水,播前贮足墒,常年播后至拔节前不会出现严重水分亏缺,耗水土层主要在中上层,拔节后下层耗水增加,到成熟期2米土体通体耗水。3年平均对土壤贮水的消耗量占总耗水量67%,显著高于春灌2水处理(35%)。与春灌处理相比,贮墒旱作小麦对土壤贮水的消耗量增加了 99 mm,总耗水量减少了 52 mm,水分利用效率无显著差异,均达到1.8 kg·m-3以上。在周年冬小麦-夏玉米两熟种植体系中,贮墒旱作冬小麦收获后2 m 土体水分库容多增加了 99 mm,夏季多存储降水63 mm,使全年蒸散量减少了 115 mm,并使夏玉米水分利用效率提高15.8%,全年水分利用效率提高5.2%。(3)贮墒旱作冬小麦降低了拔节后对氮素的吸收强度,降低了植株总吸氮量,但提高了氮素收获指数和氮素利用效率。与春灌2水相比,在同样的施氮量下,贮墒旱作小麦平均总吸氮量降低25.7%,拔节后的吸氮量及其所占总吸氮比例显著降低,但氮素的物质生产效率显著提高;籽粒氮素来自花后吸收的比例减小,但来自花前贮藏氮素转运的比例增加,使植株氮收获指数显著提高,籽粒氮浓度维持稳定。贮墒旱作小麦的氮肥偏生产力较低,但氮素利用效率显著较高。在周年冬小麦-夏玉米两熟种植体系中,冬小麦贮墒旱作降低了后茬夏玉米的氮素吸收,也提高了夏玉米氮收获指数和氮素利用效率,使全年氮利用效率显著提高。(4)贮墒旱作冬小麦在中等施氮量(225 kg hm-2)下可获得高产和高水氮利用效率的协调。贮墒旱作冬小麦实行一次性施肥(底肥),在180-270 kg hm-2施氮范围内,增施氮肥,提高了生物产量,但收获指数稳定;增加了总粒数,但千粒重稳定;提高了籽粒产量,但中氮(225 kg hm-2)和高氮(270kghm-2)处理差异不显著;增加了氮素吸收量,但氮利用效率稳定,氮收获指数下降,氮肥偏生产率显著下降;增加了总耗水量,但水分利用效率稳定。综合协调产量和水氮利用效率,以中等施氮量(225 kg hm-2)为佳。(5)贮墒旱作栽培播前2m土体最适贮墒量为田间持水量的85-90%,此贮墒量可获得最高产量和水分利用效率。黑龙江低平原区中壤土 2 m 土体最大贮水量可达700 mm,有效贮水量可达445 mm,播前不同贮墒量试验表明,随2m 土体土壤相对含水量增加,小麦产量和总耗水量均增加,在土壤相对含水量达90%时小麦产量已达最大,在土壤相对含水量达85%时小麦水分利用效率达最高。土壤相对含水量低于80%时不能获得6000 kg hm-2以上产量,但土壤相对含水量超过90%时无效耗水量增加,水分利用效率降低。(6)适应贮墒旱作栽培的高产高水效品种,其共同特征表现为群体容穗量大、穗粒数适中、千粒重和收获指数较高。所选19个品种在贮墒旱作条件下的平均产量为6733 kg hm-2,但品种间产量和水分利用效率有显著差异,高产高水效品种特征表现为:株高中等,穗数多,穗粒数适中,群体库容量较大,单株叶面积较小,群体叶面积指数较高,非叶绿色器官面积适中,穗叶比、粒叶比高;籽粒生长前中期冠层衰老速度较慢,但后期衰老速度较快,灌浆强度较高,千粒重和收获指数明显较高。综合研究认为,贮墒旱作模式在足墒播种基础上免去了生育期灌溉(休灌),大幅度减少了灌溉用水,同时简化了作业管理,是一种适度丰产和节水高效的小麦栽培模式,在地下水严重超采地区的规模化小麦生产中具有实用推广意义,特别是将周年贮墒旱作模式(冬小麦-夏玉米贮墒旱作,小麦生育期休灌)与现行周年节水灌溉模式(冬小麦-夏玉米节水栽培,小麦春季浇1-2水)以及季节性休耕(一年一季玉米)模式合理搭配布局,建立轮作休耕、休灌节水生产体系,将能为区域农业实现减灌压采与稳粮增收的结合走出一条新路。
[Abstract]:In the restricted area of North China water resources, reduce the irrigation of winter wheat to reduce the over exploitation of groundwater has important significance. The current extension of wheat cultivation technology of spring irrigation 1-2 (75-150 mm, chunguan) to further reduce the amount of irrigation, we put forward the "dry storage moisture" cultivation mode, which is stored before sowing enough moisture, fertility during the period of no irrigation. The mode of technology has already begun demonstration applications, but its yield and water and nitrogen use characteristics and mechanisms still need to further clarify. This study over exploitation of groundwater in Hebei winter wheat summer maize cropping system in two, by setting the winter wheat storage moisture dry farming and water-saving irrigation (irrigation in spring 2 water) comparison tests of two kinds of modes and different water storage amount, nitrogen content and different varieties of effects on moisture in dry storage system, studied the population dynamics of water storage in dry cultivation, source sink properties, yield, water consumption The characteristics of nitrogen utilization, and comprehensive analysis of the production efficiency and potential benefits. The main results are as follows: (1) the yield of Winter Wheat in dry storage moisture model below 2 water spring irrigation mode is mainly to reduce the population of the total grain number and yield, but before transport and storage material of seed contribution rate increased significantly can still get 6500 kg 1000 grain weight increased, hm-2 above the level of output, the annual winter wheat summer maize storage moisture dry yield was 17000 kg hm-2 more than 3 consecutive years of storage moisture of Winter Wheat in Dryland yield was 6694-7432 kg hm-2, the average yield ratio of 2 water reducing 16.6%. spring spring irrigation mode without irrigation reduced the percentage of productive tillers, cause the spike number decreased; reduced flowering biomass, resulting in reduced grain number; reduced the individual plant type, reduced leaf area index. But the increase of panicle leaf ratio and grain leaf ratio, increased sink source ratio, promote the storage in vegetative organs before anthesis Photosynthate transport, increased grain filling rate, grain weight increased significantly. In the two anniversary of winter wheat summer maize cropping system, soil moisture storage of Winter Wheat in Dryland of flowering and early maturity, yield the 5-7 temperature of summer maize resources to the sky, is conducive to the stable production of corn, the annual output to maintain high yield level. By increasing basic seedling to increase the spike number, dry storage moisture the yield of wheat can be increased further. (2) water storage of Winter Wheat in Dryland without irrigation in growing period, significantly reduced the total water consumption of wheat harvest, after freeing up larger storage capacity of soil increased summer precipitation, the annual water use efficiency. The soil water consumption of Winter Wheat in Dryland is the source of growth period precipitation and soil water storage before sowing, storing enough moisture, perennial after sowing to jointing will not appear serious water deficit, soil water consumption is mainly in the upper and lower water consumption increased after jointing stage to mature stage, 2 meters of soil body .3 the average annual water consumption of soil water consumption to total water consumption of 67%, significantly higher than the 2 spring irrigation water treatment (35%). Compared with the spring irrigation treatment, the consumption of soil water storage of the soil moisture storage in Rainfed Wheat increased by 99 mm, the total water consumption was reduced by 52 mm, the water use efficiency had no significant difference. Are more than 1.8 kg - m-3. In the two anniversary of winter wheat summer maize cropping system, soil moisture storage of Winter Wheat in dryland were harvested after 2 m soil moisture storage capacity of more than 99 mm, summer precipitation storage is 63 mm, the annual evapotranspiration decreased by 115 mm, and the water use efficiency of summer maize increased by 15.8% the annual water use, improve the efficiency of 5.2%. (3) absorption intensity on the nitrogen storage moisture of Winter Wheat in Dryland was reduced after jointing, reduce the plant total nitrogen content, but increased the nitrogen use efficiency and nitrogen harvest index. Compared with 2 in the spring irrigation water, nitrogen fertilizer under the same moisture storage in Rainfed Wheat average The total nitrogen content decreased 25.7%, nitrogen uptake after jointing stage and total nitrogen ratio decreased significantly, but the production efficiency of nitrogen increased significantly; nitrogen absorption from after anthesis was reduced, but from before storage nitrogen translocation increased, the nitrogen harvest means significantly increased, grain nitrogen concentration to maintain a stable storage. The moisture in Rainfed wheat nitrogen partial productivity is low, but the nitrogen utilization efficiency was significantly higher. In the two anniversary of winter wheat summer maize cropping system in winter wheat dry storage moisture decreased after nitrogen uptake of summer maize crop, but also improve the maize nitrogen harvest index and nitrogen use efficiency, so that the annual the nitrogen use efficiency increased significantly. (4) water storage of Winter Wheat in Dryland under moderate nitrogen (225 kg hm-2) can be obtained with high yield and high nitrogen and water use efficiency of Winter Wheat in dryland soil moisture storage coordination. The implementation of a one-time fertilizer (fertilizer), 180-270 kg hm- 2 range of nitrogen, nitrogen fertilizer, improve the yield, but the harvest index is stable; increase the total grain number, grain weight but stable; improve the grain yield, but nitrogen (225 kg hm-2) and high nitrogen (270kghm-2) treatment had no significant difference; but increased nitrogen uptake, nitrogen use efficiency stability, decrease of nitrogen harvest index, nitrogen partial production rate decreased significantly; the increase in the total water consumption, but water use efficiency and stability. The comprehensive coordination of yield and water and nitrogen use efficiency, nitrogen in the medium (225 kg hm-2) is preferred. (5) the water dry cultivation before sowing soil optimum moisture content storage 2m for the 85-90% of field capacity, the moisture storage quantity can be obtained the highest yield and water use efficiency. Soil in Heilongjiang low plain areas and 2 m soil maximum water content of up to 700 mm, the effective water storage can reach 445 mm before sowing in different moisture storage volume showed that with the 2m phase of soil water content increased, the yield of wheat and The total water consumption increased, the relative water content in soil was 90% when wheat yield has reached the maximum, the relative water content in soil of 85% wheat water use efficiency was the highest. Kg hm-2 6000 cannot be obtained above yield relative soil water content was lower than 80%, but the relative soil water content more than 90% invalid for the increase of water consumption, water the utilization efficiency decreased. (6) to high yield and high water use efficiency in Dryland Cultivation varieties of storage, the common features of group containing large amount of grain number per panicle, 1000 grain weight and moderate, the higher harvest index. The average yield of 19 selected varieties in the soil under dry conditions was 6733 kg hm-2, but the yield among varieties and a significant difference in water use efficiency, high yield and high water use efficiency varieties characterized by medium height, panicle number, panicle moderate population sink capacity is larger, smaller leaf area, higher leaf area index groups, non leaf organs of moderate size, The ratio of panicle, grain leaf ratio; grain growth before the mid canopy senescence speed is slow, but later aging fast, high strength grouting, 1000 grain weight and harvest index was significantly higher. It is removed from the storage mode, moisture dry irrigation in growing period in the seeding foot basis (Hugh irrigation), greatly reduce the irrigation water. At the same time, simplifying the operation management, is a moderately high yield and water-saving wheat cultivation mode, has great practical significance in wheat production scale groundwater overdraft area, especially the annual storage moisture dry mode (winter wheat and summer maize in dryland wheat storage water, irrigation and water saving Hugh) current anniversary irrigation mode (winter wheat and summer maize cultivation water, spring wheat poured 1-2 water) and seasonal fallow (Year season maize) mode reasonable collocation layout, establish rotation fallow, Hugh water-saving irrigation system of production area will be able to The field agriculture realizes the combination of reducing irrigation and mining, stabilizing grain and increasing income.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S512.11

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