【作者】 郭红梅；

【导师】 王宏庭；

【作者基本信息】 山西大学 ， 水土保持与荒漠化防治， 2009， 硕士

【摘要】 土壤-作物体系对人类社会的生存、发展、繁荣和稳定发挥着基础性作用。肥料是粮食的“粮食”,施用化肥在过去、现在和将来都是我国最有效的粮食增产措施之一。当前形势下,化肥施用（尤其氮肥）不仅要求进一步提高作物产量、品质、增加农民收益,还要求兼顾保护生态环境和农业可持续发展等多重目标。如何实现施肥目标的多元化,提高肥料利用率,是摆在农业科学工作者面前的重大技术问题。本文选择山西粮食主产区代表两种种植制度（一年一作、一年两作）的忻州市忻府区和临汾市尧都区的农田作为研究对象,通过田间试验与室内分析相结合的方法,探索研究了当前两种种植制度下土壤-作物体系内氮养分的调控技术,旨在实现高产、高效、优质和环境友好等多重目标,取得了如下主要结果与新的进展:1.一年一作的春玉米种植制度下施肥结果显示:（1）在当前普施105kg P₂O₅/hm²、120kg K₂O/hm²的生产条件下,增施氮肥（240kg N/hm²）仍是提高产量、增加收益的重要措施。施氮处理与不施氮肥处理比较,产量和收益均达到极显著水平,每公顷增产2342-3752kg,增产率达30.5%-48.8%,增收幅度为2577-4692元/hm²。氮肥的农学效益为9.8-15.6kg/kg。但不同氮肥分配方式存在差异,表现在产量、收益及氮肥农学效益等指标上。处理4的产量、纯收益和氮肥利用率均表现最高,分别为11440kg/hm²、15234元/hm²、15.6kg/kg;而处理1则表现最低,分别为10030 kg/hm²、13119元/hm²、9.8kg/kg。按从高到低的排序为:处理4（1/2N作基肥+1/2N作追肥）＞处理5（1/2N作追肥+1/2N作追肥）＞处理3（1/3N作基肥+1/3N作追肥+1/3N作追肥）＞处理2（1/3N作基肥+2/3N作追肥）＞处理1（全部氮肥作基肥,农民习惯方式）。（2）氮肥施用促进春玉米的生长发育和对养分的吸收。处理4氮养分吸收量最高,为239.6kg/hm²,处理1氮养分吸收量最低,为205.8kg/hm²;氮肥利用率也表现为处理4最高,为42.1%,处理1的氮肥利用率最低,为28.0%。不同氮肥处理的养分吸收量和氮肥利用率由高到低的排序为处理4＞处理5＞处理3＞处理2＞处理1,与产量和收益的表现一致。从氮素表观平衡来看,处理4基本上收支平衡,其它四个施氮处理均有不同程度的盈余。而处理6由于不施氮肥表现大量亏缺,为-138.6kg/hm²。（3）从整个春玉米生育期土壤NO₃^--N含量的监测结果看,土壤表层NO₃^--N含量主要随施氮量的变化而变化。在0-120cm土层中,硝态氮积累量不同处理均表现从上到下依次呈降低的态势,在0-40cm的硝态氮积累量最高,占到整个垂直剖面的60%以上。处理4在0-120cm土壤剖面硝态氮含量和积累量均低于其它处理。（4）以上结果综合显示,一年一作的春玉米种植制度下,施氮240kg N/hm²,以1/2N底施、1/2N拔节期追施效果最好,可以实现高产、高效、环境友好的多重目标。2.一年两作的冬小麦/夏玉米种植制度下施肥结果显示:（1）在当前普施150kgP₂O₅/hm²、150kg K₂O/hm²的生产条件下,增施氮肥（小麦施用225kg N/hm²、夏玉米施用195 kg N/hm²）仍是提高作物（冬小麦/夏玉米）产量、增加收益的重要措施。施氮处理与不施氮肥处理比较,冬小麦每公顷增产2774-3381kg,增产率达54.3%-66.2%,增收幅度为3367-4262元/hm²;夏玉米每公顷增产1461-2299kg,增产率达20.4%-32.1%,增收幅度为1080-2336元/hm²。（2）不同氮肥分配方式存在差异,冬小麦季各处理相比较,以处理5（1/3N作基肥,2/3N返青期作追肥）获得最高产量和收益,分别为8489 kg/hm²和9744元/hm²;处理4（1/4N作基肥+1/4N返青期作追肥+1/4拔节期作追肥+1/4N抽穗期作追肥）产量与收益分别为8382 kg/hm²和9554元/hm²,与处理5差异不显著。处理5与处理1全部氮肥底施（农民习惯施肥方式）比较,增产607kg/hm²,增产率为7.7%,增收995元/hm²。处理5每形成100kg籽粒吸收的N最高,为2.68kg,氮肥利用率及氮肥农学效率均为处理5最高,分别为56.7%和15.0kg/kg。夏玉米季表现为处理4（1/4N 5-6叶期追施+1/4N拔节期追施+1/4N大喇叭期追施+1/4N抽雄期追施）可以获得最高产量、收益,分别为9464kg/hm²和13085元/hm²;比处理1全部氮肥一次追施（农民习惯方式）增产838kg/hm²,增产率为9.7%,产量差异达10%水平显著,增收1257元/hm²。氮肥利用率及氮肥农学效率也是处理4最高,分别为37%和11.8kg/kg,比处理1分别高14.2%和4.0 kg/kg,并且土壤硝态氮含量和积累量在环境安全范围内。（3）氮肥不同调控方式对冬小麦/夏玉米轮作体系存在显著影响,1/4N分四次施肥和1/3N作基肥+2/3N作一次追肥处理,冬小麦/夏玉米轮作体系可以获得最高产量,分别为17846kg/hm²和17671kg/hm²;收益也最高,为22638元/hm²和22391元/hm²;并获得最高养分吸收量413kg/hm²和424kg/hm²;氮肥效益分别为13.3kg/kg和12.9 kg/hm²;肥料利用率也最高,为47.6%和50.2%,明显高于农民习惯方式（37.6%）;土壤剖面硝态氮含量和积累量符合环境安全的要求。（4）以上结果综合显示,一年两作的冬小麦/夏玉米种植制度下,施氮420kgN/hm²,以1/4N分四次施肥和1/3N作基肥+2/3N作一次追肥效果最好,可以实现高产、高效、环境友好的多重目标。3.两种种植制度下的氮肥结果显示:在不同土壤类型下氮素养分调控对作物产量、农民收益、土壤养分消耗及氮肥利用率影响显著,主要表现在:（1）两种种植制度下的作物氮素养分吸收规律;春玉米整个生育期以抽雄期为界,前、后养分吸收大体上各占50%;而冬小麦以抽穗期-乳熟期吸收最多,占39.3%,其次是返青期-拔节期（18.3%）和乳熟期-成熟期（16.4%）,拔节期-抽穗期吸收15%的养分,从播种到返青期共吸收11%;夏玉米以苗期-拔节期和拔节期-大喇叭口期吸收最高,分别占31.2%和32.7%,灌浆期-成熟期为21.7%,其余三个时期总和占14.4%。（2）两种种植制度下土壤-作物体系氮养分调控对作物产量的影响:春玉米和冬小麦/夏玉米都是以处理四产量最高,说明1/2N底施+1/2N追施和分四次施肥最能满足春玉米和冬小麦/夏玉米生长需求,也与作物氮素养分吸收规律相吻合。（3）两种种植制度下土壤-作物体系氮肥调控对农民收益的影响:冬小麦/夏玉米轮作体系总收益明显高于春玉米一年一作种植体系,在一年一作（春玉米）种植系统中,以处理4（1/2N底施+1/2N拔节期追施）获得最高收益,为15234元/hm²;在冬小麦/夏玉米轮作种植系统中以1/4N分四次施肥和1/3N作基肥+2/3N作一次追肥两个处理,获得最高收益,为22638元/hm²和22391元/hm²。（4）两种种植制度下土壤-作物体系氮养分调控对土壤养分消耗的影响:除不施氮肥处理6表现明显亏缺外,春玉米种植系统和冬小麦/夏玉米轮作系统中其他施氮处理表现略有盈余,其中不同氮肥分配方式下土壤养分消耗有所差异。春玉米种植系统中以处理4（1/2N底施+1/2N追施）表现最好,冬小麦/夏玉米轮作系统中以处理5表现最好;而两种种植制度下都以处理1（全部底施的农民习惯施肥）盈余最高。（5）两种种植制度下土壤-作物体系氮肥调控对氮肥利用率的影响:两种种植制度下由于复种指数不同,一年两作种植制度下明显高于一年一作种植制度下的氮肥利用率。在同一种植制度下,不同氮肥分配方式的氮肥利用率也有差异。春玉米种植系统中以处理4（1/2N底施+1/2N追施）氮肥利用率最高,冬小麦/夏玉米轮作系统中以处理5表现最高;两种种植制度下以处理1（全部底施的农民习惯施肥）氮肥利用率最低,这也与土壤养分表观平衡相一致。更多还原

【Abstract】 Soil-crop system plays a fundamental role in living,development, prosperity and stability of human society.Fertilizer is "food" of food,and fertilizer application is one of the most effective measures for increasing food production in the past,present and future.Under the new position,fertilizer application especially nitrogen use need to further increase not only crop yield,quality and profit,but also protect ecological environment and sustainable development of agriculture.How to achieve multi-objective of fertilizer application and improve fertilizer use efficiency is a great challenge for agricultural researchers in China.In this study,Xinzhou and Linfen city were selected as two experimental sites to represent the two major cropping systems in Shanxi province.The research objective are 1) to study the influence of distribution of nitrogen fertilizer applied on crop yield, agronomic efficiency of nitrogen fertilizer,Nitrogen use efficiency and farmers’ net return under two cropping systems;2) to monitor the dynamic of soil nitrate-nitrogen in 0-100cm and 0-120cm soil under two cropping systems.Main results and new progress were summarized as following:1.The results of nitrogen fertilizer application under the cropping system of spring maize showed that（1） under the condition of 105kg P₂O₅/ha and 120kg K₂O/ha applied,adding nitrogen fertilizer（240kg N/ha） still is an important measure for improving yield and net return.Comparing the treatments of nitrogen application with the treatment of no nitrogen application,the differences of yield and net return are obviously significant. Yield increased by 2342-3752kg per hectare or 30.5-48.8%,and agronomic efficiency of nitrogen fertilizer obtained by 9.8-15.6kg/kg,and net return increased by 2577-4692 RMB.But there existed an obvious difference among the treatments of nitrogen application on indices of yield,net return and agronomic efficiency.Treatment 4（1/2 N as basal and 1/2N as topdressing at jointing stage of maize growth） helped produce the highest yield,income and agronomic efficiency by 11440kg/ha,15234￥/ha, respectively.However,treatment 1（all N applied as basal,farmer practice） produced the lowest yield,income and agronomic efficiency by 10030 kg/ha, 13119￥/ha,9.8kg/kg,respectively.The treatments were ordered as following: Treatment 4（1/2 N as basal and 1/2N as topdressing at one time）＞Treatment 5（all N as topdressing at two times,each for 1/2N）＞Treatment 3（1/3N as basal and 2/3 as topdressing at two times,each for 1/3N）＞Treatment 2（1/3N as basal and 2/3N as topdressing at one time）＞Treatment 1（all N applied as basal,farmer practice）.（2） Nitrogen application facilitated maize growth and nutrient uptake,and there existed the difference among treatments too. Treatment 4 took up the highest amount of nitrogen by 239.6kg/ha,and treatment 1 took up nitrogen nutrient by 205.8kg/ha.Nitrogen use efficiency in treatment 4 and 1 was 42.1%and 28.0%,respectively.The order was Treatment 4＞Treatment 5＞Treatment 3＞Treatment 2＞Treatment 1.As far as apparent balance of nitrogen nutrient was concerned,Treatment 4 was balance,and other treatment was slight surplus to some extent.But Treatment 6 was serious deficit duo to no nitrogen application and nitrogen deficit by 138.6kg/ha.（3） Monitoring results of soil nitrate-nitrogen content from whole maize growth indicated that soil nitrate-nitrogen content in 0-20cm layer changed with nitrogen fertilizer application.The accumulation of soil nitrate-nitrogen in the 0-120cm layer had a decreasing tendency from the top down in different treatment of nitrogen applied.And the accumulation of soil nitrate-nitrogen in 0-40cm layer accounted for 60%.The accumulation of soil nitrate-nitrogen in 0-120cm layer from Treatment 4 was less than that in other treatment.（4） Above results indicated that the application of 240kg N/ha（1/2 N as basal and 1/2N as topdressing at jointing stage of maize growth） had a good effect,and may achieve the multi-objectives of higher yield,higher efficiency and environment-friendly.2.The results of nitrogen fertilizer application in the rotation of winter wheat and summer maize showed that:（1） Base of 150kg P₂O₅/ha and 150kg K₂O/ha application,adding nitrogen fertilizer application（225kg N/ha for winter wheat and 195kg N/ha for summer maize） is still an important measure of increasing crop yield and farmers’ net return.The difference of yield and net return between the treatment of without nitrogen application and with nitrogen application in winter wheat was significant.But there were some differences among the treatments of nitrogen application.The treatment 5（1/3N for basal,2/3N dressing at jointing stage） produced the highest yield and income by 8489 kg/ha or 9744￥/ha among the treatments of nitrogen application.Treatment 4（1/4N for basal +1/4N topdressing for reviving green stage +1/4N for topdressing at jointing stage +1/4N for topdressing at heading stage） produced by 8382 kg/ha or 9554￥/ha.The difference of treatment 5 and treatment 4 was not significant.Treatment 1（all the nitrogen application for basal,farmers practices） produced by 7882kg/ha or 8749￥/ha. Comparing treatment 1 with treatment 5,wheat yield of treatment 5 increased by 607kg/ha or 7.7 percent and net return increased by 995￥/ha.In treatment 5,100kg of grain took up 2.68kg N,and nitrogen use efficiency（NUE） and agronomic efficiency（AE） of nitrogen fertilizer were 56.7%and 15.0kg/kg, respectively.While soil nitrate content and the accumulation controlled at the level of environmental safety limits.（2） In summer maize,there also were some difference among the treatments of nitrogen application on yield, income and soil nitrate-N.Treatment 4（1/4N topdressing at the stage of 5-6 leaf +1/4N topdressing at jointing stage +1/4N topdressing at the stage of horn +1/4N topdressing at tasselling stage） obtained the highest yield and income by 9464kg/ha and 13085（?）/ha,respectively.Comparing to treatment 1（all nitrogen application at the stage of 5-6 leaf,farmers practices）,yield increased by 838kg/ha or 9.7 percent,and income increased by 1257￥/ha. NUE and AE of treatment 4 were 37%and 11.8kg/kg,respectively,and higher than that of treatment 1 by 14.2%,and 4.0 kg/kg,respectively.While soil nitrate content and the accumulation controlled at the level of environmental safety limits.（3） As far as the rotation of winter wheat and summer maize was concerned,treatment 4 and treatment 5 produced higher yield by 17846kg/ha and 17671kg/ha,respectively,higher returns by 22,638￥/ha and 22,391￥/ha,respectively,and the higher nutrient uptake by 413kg/ha and 424kg/ha,respectively,nitrogen agronomic efficiency by 13.3kg/kg and 12.9kg/kg,respectively,higher nitrogen use efficiency by 47.6%and 50.2%,respectively.The difference of treatment 4 and treatment 5 was not significant,but the difference was significant between treatment 4 or treatment 5 and treatment 1.While soil nitrate content and the accumulation controlled at the level of environmental safety limits.（4） Above results indicated that while 420kg N/ha was applied within the rotation of winter wheat and summer maize,treatment 4 and treatment 5 had a good effect,and may achieve the multi-objectives of higher yield,higher efficiency and environment-friendly.3.The results of nitrogen application under two cropping systems showed that:（1） Under two cropping systems of crop nitrogen nutrient absorption law:spring maize in the whole growth period for tasselling community,before and after each nutrient absorption in general 50%;to the winter wheat heading stage-milky stage to absorb the most,accounting for 39.3%,followed by the green period-jointing stage（18.3%）,and milky stage-stage（16.4%）,the jointing stage-heading stage of nutrient absorption 15%from sowing to the green to absorb 11%of the total period;summer corn in the seedling stage-the jointing stage and jointing stage-large bell to absorb the maximum period,with respective shares of 31.2%and 32.7%, grain-filling stage-stage was 21.7%,the remaining three accounted for 14.4%of the total period.（2） Soil under two cropping systems-crop nutrient control system for nitrogen on crop yields:spring maize and winter wheat/ summer maize production is to deal with the four highest note at the end of 1/2N for basal +1/2N for top dressing and four nitrogen fertilizer can best meet the spring maize and winter wheat/summer maize growing demand, but also nitrogen and crop nutrient uptake coincides with the law.（3） Soil under two cropping systems-crop nitrogen regulation system of the impact of income for farmers:winter wheat/summer maize rotation system was significantly higher than the total receipts a year for spring maize cropping systems,one for a year（spring maize） cultivation system to treatment 4 （1/2N facilities at the end of +1/2N topdressing at jointing stage） was the highest revenue for 15,234￥/ha;in the winter wheat/summer maize rotation system in the cultivation of four fertilization 1/4N and 1/3N for basal +2/3N for the two to deal with a top dressing,the highest revenue for 22,638￥/ha and 22,391￥/ha.（4） Soil under two cropping systems-crop nutrient nitrogen regulation system of the impact of consumption of soil nutrients:In addition to fertilizer to deal with non-obvious performance deficit 6,the spring planting of corn and winter wheat/summer maize rotation system to deal with the other N the performance of a small surplus,of which the distribution of nitrogen fertilizer under different soil nutrient consumption vary.Spring maize cultivation system to deal with 4（1/2N facilities at the end of +1/2N Topdressing） the performance of the best winter wheat/ summer maize rotation system in order to deal with 5 the best performance; and under two cropping systems to treatment 1（All facilities at the end of the farmers used to fertilization） the highest surplus.（5） Soil under two cropping systems-crop system of regulation of nitrogen use efficiency of nitrogen fertilizer effects:the two cropping systems as a result of multiple crop indexes under different cropping system for year two was significantly higher than a year under a cultivation system for the use of nitrogen fertilizer rate.Planted in the same system,the distribution of different forms of nitrogen fertilizer N use efficiency also varies.Spring maize cultivation system to deal with 4（1/2N facilities at the end of +1/2N Topdressing） the highest nitrogen use efficiency of winter wheat/summer maize rotation system in order to deal with 5 the highest performance;under two cropping systems to treatment 1（all N applied as basal,farmer practice）) the lowest nitrogen use efficiency,which is also the apparent balance of soil nutrients in line.更多还原