两种施氮水平下不同基因型冬小麦叶片光合特性与形态差异的研究

田间试验研究不施N和施N(90kg/hm2)条件下“NR9405”、“9430”、“偃师9号”、“小偃6号”、“陕229”、“西农2208”、“矮丰3号”和“商188”等8种不同基因型冬小麦中后期生理特性及其叶片形态的差异结果表明,抽穗期倒二叶和灌浆期旗叶的净光合速率、气孔导度、蒸腾速率及瞬时水分利用效率在不同基因型间存在显著差异,施N仅能显著降低抽穗期倒二叶的蒸腾速率,而对功能叶的其他生理指标无明显影响。小麦成熟期旗叶和倒二叶的长度、宽度及叶面积在不同基因型间也存在极显著差异,施N对这些叶片形态指标有极显著地促进作用,基因型和N肥同时影响灌浆期旗叶的SPAD值,而叶片衰老指数主要受基因型调控。总体上看,冬小麦叶片形态指标同时受施N和基因型影响,而生理指标主要受基因型影响,N肥的影响相对较小。     

半湿润区农田生态系统氮肥对不同基因型冬小麦产量构成的影响

施N对“NR9405”、“9430”、“偃师9号”、“小偃6号”、“陕229”、“西农2208”、“矮丰3号”和“商188”这8种不同基因型冬小麦产量构成影响的田间试验结果表明,单株分蘖成穗数、单位面积粒数和单位面积株数的差异同时受基因和N素营养水平控制。“矮丰3号”和“小偃6号”单株分蘖成穗数最多,分别为2.00分蘖穗/株和1.72分蘖穗/株,“9430”最少,为0.85分蘖穗/株。从不同基因型看,施N比不施N处理增加0.74穗/株,每穗粒数在不同基因型间存在极显著差异,以“西农2208”最多,为36.73粒/穗,“NR9405”最少,为24.35粒/穗,施N对每穗粒数无显著影响。单位面积株数主要受施N影响,基因型间差异相对较小。基因型和施N同时显著影响单位面积粒数和千粒重,但基因型对千粒重的影响程度大于N肥。从2个施N水平看,单位面积籽粒产量存在显著差异,“矮丰3号”、“西农2208”、“偃师9号”、“陕229”、“9430”、“小偃6号”、“商188”和“NR9405”依次减小,“矮丰3号”为435g/m2,“NR9405”为316g/m2,相差119g/m2。施N可极显著增加单位面积籽粒产量,不同基因型施N处理平均产量为463.38g/m2,不施N处理为296.13g/m2,相差167.25g/m2,N肥对产量的影响主要与施N增加了单位面积穗数和千粒重有关。     

不同施氮量对冬小麦籽粒灌浆特性的影响

为了解氮素对冬小麦籽粒灌浆过程的影响,2010~2011年在河南温县试验基地进行田间试验,供试品种为平安8号和豫麦49-198(分别用PA-8和YM49-198表示),在120、180、240、360 kg·hm-24个施氮水平(分别用N120、N180、N240、N360表示)下,研究不同施氮量对冬小麦籽粒灌浆特征参数的影响。结果表明:施氮显著增加粒重并具有增产效应,施氮增加粒重的原因主要是延长活跃灌浆期和增加灌浆速率。适宜施氮量对增加快增期的灌浆天数效果显著,两个品种N240处理快增期对最终粒重的贡献率达到了58%,而且提高了灌浆后期的灌浆速率,N180和N240处理表现为明显高于其他处理。说明氮素具有调节灌浆速率、灌浆活跃生长期及灌浆3期划分的作用,提高粒重效果明显。     

水肥一体化施氮水平对玉米籽粒灌浆和脱水过程的影响

以玉米品种“天赐19”为材料,于2017年和2018年在宁夏引黄灌区进行滴灌水肥一体化田间试验,设置0（N0）、90（N1）、180（N2）、270（N3）、360（N4）和450（N5）kghm-2 6个氮肥水平,测定玉米百粒干鲜重,计算籽粒含水率,建立基于Logistic方程的籽粒灌浆模型并验证,分析玉米籽粒脱水动态特征,以探讨不同氮素水平对玉米籽粒灌浆和脱水过程的影响,探究明确玉米籽粒灌浆和含水量动态变化规律。结果表明：（1）滴灌水肥一体化条件下,利用2017年试验资料获得不同施氮水平玉米品种“天赐19”籽粒灌浆过程均符合Logistic方程。模型检验结果RMSE=0.203,R2=0.954（P＜0.01）。（2）各处理玉米籽粒灌浆速率均表现为先增后减的变化特征,两年试验均以施氮270kg·hm-2处理（N3）灌浆速率最大。（3）施氮使玉米达到最大灌浆速率时间（Tmax）、最大灌浆速率（max）、达到最大灌浆速率时生长量（Wmax）和活跃灌浆期（T）均有所提高,N3（270kg·hm-2）处理缩短了达到最大灌浆速率时间（Tmax）,延长了灌浆持续期（t3）。（4）运用Logistic方程将各施氮处理灌浆过程划分为渐增期、速增期和缓增期3个阶段,其中速增期灌浆速率最大,对籽粒累积贡献率最高。（5）滴灌水肥一体化追施氮肥对玉米籽粒灌浆和脱水过程的调控具有明显促进作用。各处理籽粒含水率均表现为单调下降的趋势,脱水速率在生理成熟后期差异明显。两年试验均表现为270kg·hm?2施氮处理玉米籽粒含水量较低,生理成熟后期脱水速率较快。     

滴灌施氮水平下玉米籽粒灌浆过程模拟

为了揭示水肥一体化条件下不同施氮水平对玉米籽粒灌浆过程的影响,2017～2018年在宁夏农垦平吉堡农场进行田间试验,供试品种为"天赐19",在0、90、180、270、360和450 kg/hm~2 6个施氮水平(分别用N0、N1、N2、N3、N4和N5表示)下,基于Richards方程构建和验证了滴灌水肥一体化条件下不同氮素处理中玉米籽粒灌浆过程模型,并进行灌浆特征参数分析。结果表明,不同氮素水平下玉米籽粒灌浆规律均符合Richards曲线,模型评价指标均方根误差RMSE为1.03 g/kg,标准化均方根误差n-RMSE为5.56%,稳定度较高。籽粒灌浆速率呈先增后减的变化趋势,将灌浆进程划分为渐增期、速增期和缓增期3个阶段。施氮显著增加籽粒干物质累积量,其原因主要是延长灌浆持续期和增加灌浆速率。施氮270 kg/hm~2对增加速增期的灌浆天数效果显著,使速增期对最终籽粒干物质积累量的贡献率达到了64%,并且能维持较高的后期灌浆活性。本文基于Richards方程构建的籽粒灌浆过程模型将在滴灌玉米灌浆期准确地预测籽粒灌浆特性。     

半湿润农田生态条件下施氮对不同冬小麦品种氮素转移的影响

在年均降水量632mm的黄土高原南部半湿润红油土上进行田间试验,以NR.94059、430、偃师9号、小偃6号、陕229、西农2208、矮丰3号和商188为供试材料,研究在不施氮和施氮(N.90.kg/hm2)条件下不同冬小麦品种灌浆期氮素转移的差异。结果表明,小麦氮转移量(NT)和氮转移效率(NTE)在不同品种间差异不显著,而茎鞘氮转移效率(NTES)在品种间存在显著差异(P0.05),施氮对这些指标没有显著影响。转移氮对子粒氮贡献率(NCR)在不同品种间差异显著(P0.05),而施氮对NCR没有显著影响。不同品种间NCR从大到小的顺序为NR9405、西农2208、矮丰3号、商188、偃师9号、9430、小偃6号、陕229。氮收获指数(NHI)具有显著的品种差异,NHI从大到小的顺序为陕229、9403、矮丰3号、西农2208、偃师9号、商188、NR9405、小偃6;陕229和9403的NHI超过80%,分别为81.76%和81.02%;小偃6号仅为76.62%。不同品种的氮素利用效率(NUE)存在极显著差异(P0.001),以偃师9号最高,为37.25.g/g,小偃6号最低,为29.29.g/g;施氮对NHI和NUE无显著影响。子粒含氮量与NUE间呈极显著负相关关系(r=0.918,P0.001),表明对同一个品种难以同时提高NUE和子粒含氮量。     

制种玉米种子乳线发育的水氮效应

乳线是判定玉米成熟度的重要指标之一,为明确灌水和施氮对制种玉米种子乳线发育的影响,以‘郑单958’和‘先玉335’制种玉米为研究对象,设置充分灌溉(6 000 m3·hm?2,W6000)、中度胁迫(4 500 m3·hm?2,W4500)、重度胁迫(3 000 m3·hm?2,W3000)3个灌水梯度,不施氮[0 kg(N)·hm?2,N0]、中氮[225 kg(N)·hm?2,N225]、高氮[450 kg(N)·hm?2,N450]3个施氮水平,研究不同水氮应用对制种玉米种子乳线发育进程、籽粒含水量、百粒重、籽粒脱水和灌浆速率的影响。结果表明,不同制种组合在不同水氮条件下种子乳线发育表现出明显差异;不同水氮条件下‘郑单958’乳线发育进程历时18~24 d,较‘先玉335’的33~36 d短;随灌水量增加,‘郑单958’种子乳线发育有延迟趋势,而‘先玉335’种子乳线受灌水量影响不显著;在乳线同一发育阶段,灌水和施氮均对籽粒含水量无显著影响,百粒重均表现为施氮处理显著高于不施氮;不同灌水处理间,‘郑单958’种子在重度胁迫条件下的脱水速率显著高于中度胁迫和充分灌溉,施氮量间无显著差异,‘先玉335’种子脱水速率各灌水量间无显著差异;‘郑单958’种子的灌浆速率各灌水处理间无显著差异,充分灌水条件下,不施氮处理灌浆速率显著高于施氮处理,而‘先玉335’灌浆速率随灌水量增加而增加,同一灌水条件下均是中氮处理高于不施氮和高氮处理;‘郑单958’种子每脱水1%,籽粒百粒重增加幅度在0.37~0.88 g,而‘先玉335’在0.43~1.34 g。因此,‘郑单958’种子乳线发育受灌水影响显著,水分亏缺致使种子脱水加速,乳线进程加快;‘先玉335’种子乳线发育受氮素影响显著,氮素不足和过量均影响种子灌浆,延迟乳线发育。     

玉米杂交种氮效率基因型差异

利用北京地区推广的 8个主要玉米杂交种 ,在不施N和施N条件下研究了产量、N累积量及N效率的基因型差异。结果表明 ,在不施N和施N条件下 ,不同品种之间产量的变异幅度分别为 62%、57% ;N累积总量的变异幅度则分别为 55%、48%。其中以农大 108的产量和N累积总量最高 ,中单 120和中单 2号最低。随施N量增加 ,吸收效率和N效率显著下降 ,利用效率则变化不大。在 2个施N水平下 ,N效率基因型差异主要决定于吸收效率     

调亏灌溉条件下冬小麦籽粒灌浆特征及其模拟模型

在移动式防雨棚下,采用盆栽土培方法,以冬小麦（Triticum aestivum L.）为试验材料进行了调亏灌溉（regulated deficit irrigation,RDI）试验研究,目的在于了解RDI对冬小麦籽粒灌浆特性的影响,并对其进行模拟,为建立冬小麦RDI指标与模式提供理论依据与技术参数。试验采用二因素（水分调亏阶段和调节亏水度）随机区组设计。结果表明,RDI条件下冬小麦籽粒灌浆过程符合“缓-快-慢”的“S”型生长曲线,并可用Richards方程进行较好的模拟;不同水分调亏处理间最大灌浆速率及其出现时间、平均灌浆速率、灌浆持续期、活跃生长期和3个灌浆阶段灌浆持续期,以及最终千粒质量等特征参数差异达显著水平;其中,越冬期轻度调亏具有最高的平均灌浆速率（每百粒0.234 g/d）、最大灌浆速率（每百粒0.369 g/d）、最高的第3阶段灌浆速率（每百粒0.099 g/d）和最高的千粒质量（58.46 g）。经相关和逐步回归分析灌浆参数与千粒质量的关系,结果表明,多数参数间存在着显著或极显著的相关性,其中,与千粒质量有显著或极显著相关关系的参数有最大灌浆速率、平均灌浆速率、活跃生长期和第3阶段灌浆速率等。     

氮、硫配施对冬小麦氮素利用效率及产量的影响

【目的】氮(N)、硫(S)是生物所必需的营养物质,对小麦籽粒产量和品质起着重要作用。硫素供应不足,特别是在当前大量氮素供应情况下引起的作物生理性缺硫将导致作物产量和含硫氨基酸蛋白质含量下降。本文旨在探索氮、硫配施对冬小麦氮素利用效率和籽粒产量的促进效果并提出合理的区域氮、硫施肥技术。【方法】20122013年,在河南温县以国审冬小麦品种豫麦49-198为供试材料,进行大田试验。设置不同施氮量0、120、180、240和360 kg/hm2(分别以N0、N120、N180、N240和N360表示)和施硫0和60 kg/hm2(S0和S60)试验,调查氮、硫对冬小麦干物质积累、氮素积累分配、籽粒产量和氮素利用效率的影响。【结果】对冬小麦生育后期干物质积累分析表明,干物质积累随施氮量增多而提高,相同施氮量条件下施硫较不施硫小麦干物质积累量显著提高,其中成熟期干物质积累量N180S60、N240S60和N360S60分别较N180S0、N240S0和N360S0提高2225、3607和3120 kg/hm2,而且氮素低的处理添加硫后干物质积累量高于氮素高不加硫处理,如N180S60N240S0、N240S60N360S0,处理间差异均达显著水平。随施氮量增多,冬小麦植株氮素积累总量增加,在N 240和360 kg/hm2水平,硫素供应显著增加小麦植株氮素积累。不同施氮量条件下施硫较不施硫均显著提高了小麦籽粒产量,分别提高了10.5%、18.3%、5.2%、5.6%和4.9%。随施氮量增多,氮肥偏生产力下降,氮回收效率、生理效率和农学效率则均以N 180达最高值。不同施氮水平下,施硫均显著提高了冬小麦氮素回收效率,但对氮生理效率影响不显著,其中在施N量为120、180和240kg/hm2时,施硫较不施硫氮肥偏生产力和农学效率均显著提高。【结论】在当前小麦生产中,采用控氮或减氮增硫技术措施,可实现小麦氮利用效率和籽粒产量的同步提高。在本试验地区小麦生产中,达到冬小麦稳产高效或增产高效的适宜施氮量为180 240 kg/hm2配合60 kg/hm2硫肥施用。     

红芸豆对氮素的需求规律及适宜施氮量研究

为探明山西省红芸豆的氮素需求规律与分配特征,并明确其适宜施氮量,以‘英国红’为试验材料,通过田间试验,系统监测了不同生育时期红芸豆干物质和养分的累积与分配特征,并研究了氮肥施用水平对红芸豆产量、氮素利用效率的影响。分别在山西省中部农业科学院东阳试验基地和西部地区岢岚县曹家沟村进行试验。东阳试验基地设置了4个氮水平(kg·hm~(-2))处理,分别为0(N1)、60(N2)、120(N3)和180 (N4);岢岚县曹家沟村设置5个氮水平(kg·hm~(-2))处理,分别为0 (N1)、60 (N2)、120 (N3)、180 (N4)和240 (N5)。结果表明,红芸豆在不同氮肥处理间籽粒产量、生物量和氮素累积量均表现出显著差异:籽粒产量随氮肥施用量的增加呈单峰曲线变化,两个试验点均表现为N3处理产量最高,分别为2 359.89 kg·hm~(-2)和2 452.26 kg·hm~(-2),产量差异主要来自百粒重;干物质累积随生育进程呈现"慢—快—慢"的增长趋势,两个试验点均表现出N3处理单株籽粒所占总干物质比重最高,分别为49.97%与47.65%;植株氮素累积与分配与干物质累积的变化趋势大致相同,两个试验点单株籽粒最高含氮量分别在N4(东阳)和N3(岢岚)处理,分别为每株0.72 g和0.99 g。说明合理的氮肥施用可以提高籽粒的干物质累积量和氮素的转运效率,显著提高了红芸豆植株干物质向籽粒中的转移率,增加了植株对氮素的吸收和转运能力。山西省中部地区红芸豆推荐氮肥施用量为110.36kg·hm~(-2),西部地区为126.31 kg·hm~(-2)。     

Effects of split nitrogen fertilization on post-anthesis photoassimilates,nitrogen use efficiency and grain yield in malting barley

Abstract

Split nitrogen applications are widely adopted to improve grain yield and enhance nitrogen use effective in crops. In a two-year field experiment at two eco-sites, five fractions of topdressed nitrogen of 0%, 20%, 30%, 40% and 50% were implemented. Responses of radiation interception and leaf photosynthesis after anthesis, dry matter accumulation and assimilates remobilization, nitrogen use efficiency and grain yield to fraction of topdressed nitrogen treatments were investigated in malting barley. Net photosynthetic rate of the penultimate leaf, leaf area index and light extinction coefficient increased with increasing fraction topdressed nitrogen from 0% to 30%, and then decreased from 30% to 50%. The putative gross maximum canopy photosynthesis was the highest for fraction of topdressed nitrogen of 30%, which was concomitant with the highest amount of post-anthesis accumulated assimilates. The remobilization of pre-anthesis stored assimilates from vegetative organs into grains was hardly significantly affected by fractions of topdressed nitrogen. Grain yield was the highest for fraction of topdressed nitrogen of 30%, which coincided with the highest plant nitrogen uptake and physiological and agronomic nitrogen use efficiencies. The enhanced nitrogen use efficiency was corresponding to the improved photosynthetic nitrogen-use efficiency in the leaves at fraction of topdressed nitrogen of 30%. In conclusion, appropriate fraction of topdressed nitrogen application on malting barley improved assimilation rate and nitrogen use efficiency resulting in higher grain yields and proper grain protein content in malting barley.     

行距配置方式对夏玉米氮素吸收利用及产量的影响

为确定黄淮南部夏玉米产区机械化生产适宜的行距配置方式,2012—2013年同时在河南省方城县和辉县两个试验点设置大田试验,以高、中、低3种株高类型的玉米杂交种‘先玉335’、‘郑单958’和‘512-4’为材料,设置2个种植密度(低:60 000株·hm~(-2);高:75 000株·hm~(-2))、5个行距配置方式(50 cm、60 cm、70 cm、80cm等行距和80 cm+40 cm宽窄行距),研究了不同株型玉米品种在不同密度和行距配置条件下对氮素吸收利用效率和产量的影响。结果显示,低密度种植条件下,高秆的‘XY335’和矮秆的‘512-4’均以60 cm等行距处理产量优势明显;中秆的‘ZD958’在辉县和方城分别以60 cm和70 cm等行距产量最高。在高密度种植条件下,高秆的‘XY335’和中秆的‘ZD958’均以60 cm等行距处理产量最高;而矮秆的‘512-4’则以50 cm等行距种植产量优势明显,但与60 cm等行距处理差异不显著。植株氮积累量随行距的扩大呈先升高后降低的趋势,以60 cm等行距的氮积累量较大,低密度时显著高于80 cm等行距和80 cm+40 cm宽窄行距处理,而高密度下与各行距处理差异不显著;不同品种植株氮积累量对行距反应不同,高秆品种在行距间差异不显著,中秆品种80 cm等行距最低且与其余行距处理差异显著,矮秆品种50 cm和60 cm等行距氮积累量最高且与其余行距差异显著。两个密度种植条件下,籽粒氮积累量和氮素收获指数均随行距的扩大先升高后降低,在60 cm等行距处理达到最大值,并且均显著高于其他行距处理;氮肥偏生产力随行距的扩大呈现先升高后降低的趋势,60 cm等行距处理较高,但在低密度下与其他行距处理差异不显著,高密度时与80 cm等行距处理差异显著。与其他行距处理相比,60 cm等行距处理具有相对较高的氮素吸收利用效率和产量,能够较好地协调玉米土壤与植株的氮素吸收利用关系,兼顾不同株高类型玉米品种在一定密度范围内获得高产,可作为目前黄淮南部地区夏玉米统一的行距配置方式进行推广。     

氮肥用量对旱地冬小麦产量及夏闲期土壤硝态氮变化的影响

在陕西渭北旱塬,利用长期定位试验研究了长期不同氮肥用量（0、80、160、240、320 kg hm-2）对旱地冬小麦产量形成,氮素利用,土壤硝态氮残留、夏闲期淋溶和矿化的影响。结果表明：随用量增加,施氮提高旱地小麦产量的效应下降,而土壤硝态氮残留迅速增加。作物生长当季的硝态氮残留主要分布在0～60 cm土层,施氮超过160 kg hm-2时,达56.8～211.7 kg hm-2,来源于当季施用氮肥的残留占64%～90%。夏闲期土壤硝态氮发生淋失的土层深度和硝态氮淋失量均与施氮量呈显著的抛物线关系（r = 0.988 9和0.994 0）,施氮量超过160 kg hm-2时,每增加100 kg hm-2的氮肥投入,硝态氮淋失深度和淋失量增加量分别高于27 cm和80.4 kg hm-2。平均每10 mm的夏闲期降水可使离开原土层发生淋溶的硝态氮向下移动2～4 mm。施氮量对硝态氮淋失的深度没有显著影响。夏闲期土壤氮素矿化量、来源于当季施入土壤肥料氮被生物固定后的再矿化量分别为51.8～160.9 kg hm-2和31.6～109.2 kg hm-2。基于本研究,建议渭北旱塬冬小麦施氮量控制在146～163 kg hm-2,以保证旱地小麦高产,防止过量肥料氮残留,减少淋溶风险。     

Optimizing nitrogen management strategy under wheat straw incorporation for higher rice production and nitrogen use efficiency

Nitrogen (N) application plays an important role in rice production. Limited attention has already been paid to optimizing N fertilizer management strategy for higher grain yield and nitrogen use efficiency (NUE) of rice with crop residue incorporation. Field experiments were conducted with the objective to determine the response of several N application methods to rice production and to evaluate their NUE. Three N fertilizer application methods, i.e., local farmers' N fertilizer practice (FNP), modified farmers' N fertilizer practice (MNP), and increased the amount of N fertilizer practice (INP), were adopted with zero N application as control (CK). The results showed that, compared with that under FNP, grain yield was significantly higher under MFP, owing to signficantly enhanced total spikelets as a result of more panicles per unit area. Relative to FNP, MNP markedly increased nitrogen agronomic efficiency (AE_N), nitrogen recovery efficiency (RE_N), nitrogen physiological efficiency (PE_N) and nitrogen partial factor productivity (PFP_N), but AE_N, PE_N and PFP_N of INP were significantly lower. Further analysis showed that the number of tiller, leaf area index, aboveground biomass, SPAD value, plant N content and N uptake at the early vegetative stage were improved significantly under MNP compared to those under FNP, contributing to higher total aboveground biomass and total N uptake.     

Effects of tillage and nitrogen management on soil chemical and physical properties after 23 years of continuous sorghum

Long-term tillage and nitrogen (N) management practices can have a profound impact on soil properties and nutrient availability. A great deal of research evaluating tillage and N applications on soil chemical properties has been conducted with continuous corn (Zea Mays L.) throughout the Midwest, but not on continuous grain sorghum (Sorghum bicolor (L.) Moench). The objective of this experiment was to examine the long-term effects of tillage and nitrogen applications on soil physical and chemical properties at different depths after 23 years of continuous sorghum under no-till (NT) and conventional till (CT) (fall chisel-field cultivation prior to planting) systems. Ammonium nitrate (AN), urea, and a slow release form of urea were surface broadcast at rates of 34, 67, and 135 kg N ha⁻¹. Soil samples were taken to a depth of 15 cm and separated into 2.5 cm increments. As a result of lime applied to the soil surface, soil pH in the NT and CT plots decreased with depth, ranging from 6.9 to 5.7 in the NT plots and from 6.5 to 5.9 in the CT plots. Bray-1 extractable P and NH₄OAc extractable K was 20 and 49 mg kg⁻¹ higher, respectively, in the surface 2.5 cm of NT compared to CT. Extractable Ca was not greatly influenced by tillage but extractable Mg was higher for CT compared to NT below 2.5 cm. Organic carbon (OC) under NT was significantly higher in the surface 7.5 cm of soil compared to CT. Averaged across N rates, NT had 2.7 Mg ha⁻¹ more C than CT in the surface 7.5 cm of soil. Bulk density (Δ_b) of the CT was lower at 1.07 g cm⁻³ while Δ_b of NT plots was 1.13 g cm⁻³. This study demonstrated the effect tillage has on the distribution and concentration of certain chemical soil properties.     

施锌对玉米氮磷钾肥料利用率、产量及籽粒品质的影响

施用ZnO 4.2kg/hm~2对玉米N、K元素的吸收利用存在极显著协和作用,可分别提高N、K肥料利用率35.84％和141.07％,增产7.63％,籽粒蛋白质、脂肪、淀粉和全糖含量分别增加5.63％、5.37％、2.69％和2.29％。Zn对P的吸收利用是拮抗作用,施Zn肥显著降低P肥利用率。     

Cultivation of wheat following pea and triticale/pea mixtures increases yields and nitrogen content

Abstract

An experiment was conducted in 2004–2007 at the University of Podlasie Zawady Experimental Station (52°06′N, 22°50′E), Siedlce, Poland, to examine the effect of either post-harvest residues or residues and straw of spring triticale (Triticale), field pea (Pisum sativum L.) and their mixtures containing the following proportions of both components: 75+25, 50+50, 25+75% on the subsequent crop of winter wheat (Triticum aestivum L.). A field experiment was designed as split-blocks with three replicates. Residue mass, straw mass as well as N, P, K, Ca and Mg amounts were determined in the residues and straw. The residue amount of spring triticale was the greatest. N, Ca and Mg amounts in the residues of spring triticale/field pea mixtures were similar or higher whereas P and K amounts were similar or lower compared with spring triticale residues. Spring triticale straw contained less N, P, Ca and Mg than the straw of either field pea or spring triticale/field pea mixtures. Grain yield, yield components, N content and N uptake in the grain of winter wheat following field pea and spring triticale/field pea mixtures were significantly higher compared with winter wheat following spring triticale. Increasing proportions of field pea in mixtures with spring triticale cultivated as previous crops significantly increased winter wheat grain yields as well as N content and uptake. The residues of the previous crops combined with the straw significantly increased winter wheat grain yield, number of ears per m², number of grains in an ear, thousand-grain weight and N content and uptake. The highest winter wheat grain yield and N uptake were determined following an application of residues and straw of field pea and 25+75% spring triticale/field pea mixture. The grain of winter wheat after field pea had the greatest N content.     

不同形态氮肥与结实期水分胁迫对水稻氮素利用及产量的影响

以杂交籼稻"冈优527"和常规粳稻"农垦57"为材料,设置硫酸铵(铵硝配比100∶0)、硝酸铵(铵硝配比50∶50)、硝酸钠(铵硝配比0∶100)3种形态氮肥及结实期4种水分胁迫处理[土壤水势(ψsoil)分别为0 kPa、25 kPa、50 kPa、75 kPa,持续处理14 d],研究其对水稻氮素吸收利用及产量的影响。结果表明:结实期土壤水势在25 kPa时,铵硝比50∶50处理较铵硝比100∶0处理的水稻籽粒产量增加显著,铵态氮比例≥50%时,适当增加硝态氮比例可缓解土壤水分严重不足对产量形成的不利影响。当土壤水势在0~25 kPa范围内适当增加硝态氮肥比例,有利于促进稻株氮素累积,尽管与纯铵态氮处理间未达到显著水平,但与纯硝态氮处理间差异均达到显著水平。土壤水势≤50 kPa时,增加硝态氮产量优势减弱,相反增加铵态氮肥的比例更有利于产量形成。增加铵态氮有利于分蘖盛期前稻株对氮的吸收,但在保证一定铵态氮比例下,适当增加硝态氮有利于加快中、后期对氮素的吸收速度和氮素累积量,为结实期氮素向籽粒转运及提高氮素利用效率提供保证。适度水分胁迫能促进结实期水稻对氮素的吸收,促进结实期干物质累积,提高各器官中营养物质向籽粒运转,进而有利于收获指数的提高。杂交籼稻"冈优527"和常规粳稻"农垦57"对不同形态氮肥与结实期水分胁迫下氮素利用及产量的响应趋势基本一致。     

Effects of nitrogen,phosphorus, and potassium nutrition on yield,rates of kernel growth and grain filling periods of two corn hybrids

Abstract

Depression of corn grain yields from nutrient stress has been studied extensively, but effects of nutrient stress on rates of corn development and yield determinants are less well understood. Nutritional effects on the number of kernels/unit area, growth rate/kernel, and duration of growth have implications concerning fertilization practices and yield potentials of crops. Two corn hybrids with equivalent silking dates but having different grain filling periods were grown in a field experiment. Fertility treatments consisted of a N series receiving 0, 112, or 336 kg of N/ha and a P‐K series receiving factorial combinations of 0, 22, or 112 kg of P/ha and 0, 56, or 224 kg of K/ha. Dates for grain initiation and maturity were determined for each plot along with tissue analyses of ear leaves, grain yields, and kernel weights. Concentrations of N and K in ear leaves generally corresponded to treatment levels of these nutrients, although Pioneer Hi‐bred 3390 appeared to be less efficient than Pioneer Hi‐bred 3334 in K uptake. Effects of nutrient stress on yield determinants depended on the determinant and nutrient under consideration. Severe N stress did not change length of grain filling periods, but decreased kernel numbers 30 to 70%. Stress for K, on the other hand, shortened grain filling periods about 13% and had only a slight effect on kernel number. Negligible P stress occurred in the experiment. The two hybrids produced equal quantities of grain/ha/day but the hybrid with a longer filling period (Pioneer 3334) filled many more kernels at a slightly slower rate and for a longer period of time to give a significantly greater grain yield compared to Pioneer 3390.