不同氮肥施用后土壤各氮库的动态研究   总被引：18，自引：1，他引：18  

巨晓棠  刘学军  张福锁 《中国生态农业学报》2004,12(1):92-94

盆栽试验研究不同N肥施用后土壤各N库的动态结果表明 ,等N量均匀混施下尿素、碳酸氢铵、硫酸铵和硝酸钙 4种N肥处理小麦生物量和吸N量均无显著差异。NH4 N肥和酰胺态氮肥的硝化作用在 14d内完成。尿素、碳酸氢铵和硫酸铵处理土壤微生物N含量均随作物生长呈下降趋势 ,这可能是作物对微生物N库的消耗所致。作物对“老固定态”铵的利用能力很弱。施入NH4 N肥或酰胺态氮肥前期显著增加土壤固定态铵含量 ,并被作物生长后期吸收利用。 4种N肥表观回收率、表现损失和固定率均无显著差异。  相似文献   

施入~(15)N标记氮肥在长期不同培肥土壤的残留及其利用     

赵伟  梁斌  周建斌 《土壤学报》2015,52(3):587-596

采用盆栽试验和短期矿化培养相结合的方法,研究了施入15N标记氮肥(+N)及其与秸秆配施(+1/2N+1/2S)在3种长期(19年)不同培肥土壤(即:No-F,长期不施肥土壤;NPK,长期施用NPK化肥土壤;MNPK,长期有机无机肥配施土壤)中的残留及其矿化和作物吸收特性。结果表明,第一季小麦收获后,+1/2N+1/2S处理下三供试土壤和+N处理下的NPK和MNPK土壤残留肥料氮(残留15N)中有82.6%~95.1%以有机态存,而+N处理下No-F土壤残留15N有47.7%以矿质态存在。经过28 d矿化培养后,与NPK土壤相比,MNPK土壤氮素净矿化量显著增加,增幅为39%~49%;NPK和MNPK土壤残留肥料氮(残留15N)矿化量为1.23~1.90 mg kg-1,占总残留15N的2.78%~5.53%,均显著高于No-F土壤。与+N处理相比,+1/2N+1/2S处理显著提高了3供试土壤氮素净矿化量,但两施肥处理对NPK和MNPK土壤残留15N矿化量无显著影响。+N处理下No-F土壤残留15N的利用率为20%,显著高于NPK(9%)和MNPK(12%)土壤。两种施肥处理下,MNPK土壤残留15N的利用率均显著高于NPK土壤。短期培养期间土壤氮素矿化量和第二季小麦生育期作物吸氮量呈显著性正相关,而残留15N矿化量和第二季小麦吸收残留15N量间无显著性相关关系。长期有机无机配施可以提高土壤残留肥料氮的矿化量及有效性。  相似文献   

太湖地区水稻季氮肥的作物回收和损失研究   总被引：9，自引：3，他引：9  

田玉华  尹斌  贺发云  朱兆良 《植物营养与肥料学报》2009,15(1):55-61

在太湖地区水稻土上,采用田间微区15N示踪试验研究了不同氮磷肥配合下水稻季氮肥去向以及残留肥料氮在麦季的吸收利用。结果表明,水稻当季作物对肥料氮的回收率为29%～39%,土壤残留肥料氮的后效很低,后季冬小麦仅利用土壤残留肥料氮的2.4%～5.2%。经过连续两个稻麦轮作,0—60cm土壤中残留肥料氮占施氮量的11%～13%,绝大多数在0—20 cm表层土中。水稻季施用的肥料氮向耕层以下移动很少,20—60 cm土层中累积肥料氮仅占施氮量的0.6%～1.1%,主要发生在小麦季及水稻泡田时期,肥料氮损失占施氮量的47～54%,氨挥发和硝化反硝化气态损失是主要途径。高氮和高磷处理没有增加作物产量和氮肥利用率,过量施氮或施磷无益于作物增产和氮肥吸收利用。  相似文献   

稻草还田与施氮水平对土壤氮素供应和水稻产量的影响   总被引：3，自引：0，他引：3  

佘冬立  王凯荣  谢小立  彭英湘  陈敏 《土壤通报》2007,38(2):296-300

比较研究了3年定位试验后稻草还田和施N水平对红壤双季稻作系统土壤供N能力、水稻吸N特征和水稻生产的影响。结果表明:头年晚稻草秋季还田对来年早稻土壤NH4+-N和作物吸N量的提高具有促进作用,而早稻新鲜稻草还田使晚稻土壤NH4+-N和作物吸N量均略低于移走稻草处理。稻草还田处理3年后,土壤可矿化N与移走稻草处理相比提高了35.4%~53.9%,且水稻各生育期干物质生产量均高于移走稻草处理,稻谷增产率达4.0%~4.7%。施用N肥可以显著增加土壤NH4+-N和可矿化N含量,且随着N肥用量的增加,水稻植株的累积吸N量和系统生产力(地上干物质量和产量)均显著的增加,建议N(全年施N量185 kg hm-2)和习惯N(全年施N量265 kg hm-2)处理相对于无N处理的增产率分别为35.2%和45.3%,而N肥的吸收利用效率分别为27%和25%,农学产量效益分别为每公斤纯N增产谷粒12.7 kg和11.4 kg。  相似文献   

冬小麦生长期土壤固定态铵与微生物氮的动态研究   总被引：3，自引：0，他引：3  

巨晓棠  刘学军  张福锁 《中国生态农业学报》2004,12(1):90-91

田间试验研究冬小麦生长期土壤固定态铵和微生物N动态变化结果表明 ,施入基肥后土壤固定态铵显著上升 ,春季后固定态铵显著下降 ,至扬花期降至最低点。作物生长后期随吸N量的降低 ,各施肥处理固定态铵含量约升至播前水平。冬小麦全生育期土壤微生物N呈明显季节变化 ,施基肥后短期内有所升高 ,且春季施肥后出现第 2次升高 ,至扬花期土壤微生物N降至最低点 ,至生长后期重新回升。  相似文献   

棕壤对施入肥料氮的矿物固定及其动态研究   总被引：2，自引：0，他引：2  

韩晓日  陈恩凤  郭鹏程 《土壤通报》1999,30(3):15

应用１５Ｎ示踪技术研究了棕壤长期定位试验１４年后的,不同施肥处理土壤对施入肥料铵的矿物固定及其动态。结果表明,施入肥料铵的固定率在２６４％～４１０％。施钾肥能促进铵的矿物固定,而施用有机肥则减少肥料铵的矿物固定。土壤矿物对施入肥料铵的固定与释放主要受土壤交换性铵水平控制。在小麦生长期间新固定的肥料铵基本上释放出来。不同时期土壤固定１５ＮＨ＋４的释放量与小麦吸收１５Ｎ量之间存在明显的正相关关系（ｒ＝０．８７１,ｎ＝２０）。  相似文献   

南京郊区大白菜生长期氮素的供应及利用   总被引：2，自引：0，他引：2  

贺发云  尹斌  曹兵  蔡贵信 《土壤》2006,38(6):692-697

在南京郊区露地生产条件下,研究了不同施肥处理秋季大白菜生长期的土壤N素供应、作物养分吸收利用和肥料N素损失。结果表明,在大白菜整个生育期,耕层土壤供N量为50.7kg/hm2,占土壤全N量的1.07%。作物收获期地上部分生物量和N素含量随施N量的提高而升高,施用N肥显著增加了大白菜的生物量,提高幅度高达3~4倍。植株吸收N量70%以上来源于肥料N。在本试验条件下,尿素N肥表观利用率为26%~35%,土壤NO3--N含量随N肥施用量的增加而升高,主要累积在0~40cm土层中。  相似文献   

黄壤上烤烟氮素积累、分配及利用的研究   总被引：3，自引：0，他引：3  

王鹏  曾玲玲  王发鹏  周建朝  张维理  李志宏 《植物营养与肥料学报》2009,15(3):677-682

田间条件下,利用同位素15N示踪技术于黄壤有机质含量分别为19.2和40.7 g/kg和当地推荐最佳氮肥用量基础上,设15N用量分别为105和82.5 kg/hm2的情况下,研究了两个试验点烤烟15N积累、吸收比例、氮素利用率及15N在各器官分配。结果表明,在二种有机质含量的黄壤上,烤烟15N吸收规律相似,于烤烟移栽后3~5周内,烟株吸收15N较少,5周后15N积累量明显增加,到移栽后13周达到高峰,肥料15N吸收时间拖后;二种土壤上,肥料15N在整个生育期内积累量分别为28.41和26.55 kg/hm2。烟株于移栽后3~5周来自肥料15N占吸收总氮的比例为53.84%～71.33%,氮（15N）肥利用率为1.11%～7.34%;到烟叶采收结束（移栽后17周）时,烟株来自肥料15N占吸收总氮的比例为28.69%～29.75%,氮（15N）肥利用率为27.06%～32.18%。各个部位烟叶采收结束时,二种土壤上,肥料15N在上部、中部、下部烟叶及茎和花积累分别占吸收肥料总15N的35.08%~35.26%、25.87%~26.19%、17.92%~18.25%和22.73%~24.49%,肥料15N主要集中在中、上部烟叶。可见,肥料氮吸收时期拖后,土壤后期供氮能力强和中上部烟叶肥料氮比例较高是黄壤烟区烤烟氮素营养存在的主要问题。  相似文献   

控释肥对土壤氮素反硝化损失和N_2O排放的影响     

丁洪  王跃思  秦胜金  张玉树  项虹艳  李卫华 《农业环境保护》2010,(5):1015-1019

在实验室培养条件下,研究了3种控释肥对土壤氮素硝化反硝化损失和N2O排放的影响。结果表明,控释肥具有明显控制氮素释放的作用。在培养的前23d,控释肥处理的土壤NH4＋-N含量低于尿素处理,而后则高于尿素处理。各肥料处理土壤NO3--N含量均随培养时间逐渐增加,但不同肥料处理间差异不显著。28d培养期间,施入控释肥的土壤反硝化氮损失量为30.33～30.91mg N·kg-1土,比施加尿素处理土壤低13.83～14.41mgN·kg-1土,差异达到显著水平（P〈0.05）,控释肥降低氮肥的反硝化损失达3.45～3.60个百分点。控释肥处理土壤N2O累积释放量约为15.71～20.45mgN·kg-1土,比尿素处理高0.86～5.60mgN·kg-1土,但差异未达到显著水平。  相似文献   

改性尿素N在土壤-烟株系统中的分布规律研究   总被引：5，自引：0，他引：5  

刘义新  韩移旺  江玉平  于黎莎  王彦亭  陈江华  刘武定 《核农学报》2002,16(1):53-57

在盆栽烟草条件下采用15N示踪方法研究尿素改性前后N在土壤烟株中的分布规律 ,并比较尿素改性前后N的利用率大小。结果表明 ,尿素改性后比改性前烟叶增产 2 5 1 6% ,达 1 %显著水准。烟株全N量 ,改性后是改性前处理的 1 4 5 7%。从肥料中吸收的N量 ,改性后是改性前处理的 1 2 7 9%。从土壤中吸收的N量 ,改性后是改性前处理的 1 58 3 %。N肥利用率 ,改性后处理为 45 8% ,比改性前处理提高1 0 1个百分点。N的回收率 ,改性后处理达 98 3 % ,比改性前处理提高 1 2 8个百分点。改性尿素省肥增产的主要原因是刺激作物从土壤N库中吸收了较多N素 ,同时所施N肥的利用率有明显提高  相似文献   

水分状况与供氮水平对土壤可溶性氮素形态变化的影响   总被引：3，自引：0，他引：3  

李亚娟  杨俞娟  张友润  滕一波  方萍  林咸永 《植物营养与肥料学报》2010,16(5):1153-1160

采用通气培养试验,研究比较了两种水稻土在不同水分和供氮水平下的矿质氮(TMN)和可溶性有机氮(SON)的变化特征。结果表明,加氮处理及淹水培养均显著提高青紫泥的NH4+-N含量;除加氮处理淹水培养第7 d外,潮土NH4+-N含量并未因加氮处理或淹水培养而明显升高。无论加氮与否,控水处理显著提高两种土壤的NO3--N含量,其中潮土始见于培养第7 d,青紫泥则始于培养后21 d;加氮处理可显著提高淹水培养潮土NO3--N含量,却未能提高淹水培养青紫泥NO3--N含量。两种土壤的SON含量从开始培养即逐步升高,至培养21～35 d达高峰期,随后急剧下降并回落至基础土样的水平;SON含量高峰期,潮土SON/TSN最高达80%以上,青紫泥也达60%。综上所述,潮土不仅在控水条件下具有很强硝化作用,在淹水条件下的硝化作用也不容忽视,因此氮肥在潮土中以硝态氮的形式流失的风险比青紫泥更值得关注;在SON含量高峰期,两种土壤的可溶性有机氮的流失风险也应予以重视。  相似文献   

灌溉施用氮肥后氮素在土壤中的转化及淋失状况: 土柱模拟研究   总被引：4，自引：0，他引：4  

ZHOU Jian-Bin  XI Jin-Gen  CHEN Zhu-Jun  LI Sheng-Xiu 《土壤圈》2006,16(2):245-252

A soil column method was used to compare the effect of drip fertigation (the application of fertilizer through drip irrigation systems, DFI) on the leaching loss and transformation of urea-N in soil with that of surface fertilization combined with flood irrigation (SFI), and to study the leaching loss and transformation of three kinds of nitrogen fertilizers (nitrate fertilizer, ammonium fertilizer, and urea fertilizer) in two contrasting soils after the fertigation. In comparison to SFI, DFI decreased leaching loss of urea-N from the soil and increased the mineral N (NH₄⁺-N + NO₃^--N) in the soil. The N leached from a clay loam soil ranged from 5.7% to 9.6% of the total N added as fertilizer, whereas for a sandy loam soil they ranged between 16.2% and 30.4%. Leaching losses of mineral N were higher when nitrate fertilizer was used compared to urea or ammonium fertilizer. Compared to the control (without urea addition), on the first day when soils were fertigated with urea, there were increases in NH₄⁺-N in the soils. This confirmed the rapid hydrolysis of urea in soil during fertigation. NH₄⁺-N in soils reached a peak about 5 days after fertigation, and due to nitrification it began to decrease at day 10. After applying NH₄⁺-N fertilizer and urea and during the incubation period, the mineral nitrogen in the soil decreased. This may be related to the occurrence of NH₄⁺-N fixation or volatilization in the soil during the fertigation process.  相似文献   

施氮和豌豆/玉米间作对土壤无机氮时空分布的影响   总被引：3，自引：1，他引：3  

吴科生  宋尚有  李隆  孙建好  包兴国  李伟绮 《中国生态农业学报》2014,22(12):1397-1404

为探明甘肃河西走廊绿洲灌区豌豆/玉米间作体系土壤无机氮时空分布现状和过量施用氮肥对环境的影响,2011年在田间试验条件下,采用土钻法采集土壤剖面样品,采用Ca Cl2溶液浸提、流动分析仪测定土壤无机氮含量的方法,研究了不同氮水平[0 kg(N)·hm?2、75 kg(N)·hm?2、150 kg(N)·hm?2、300 kg(N)·hm?2、450 kg(N)·hm?2]下豌豆/玉米间作体系土壤无机氮时空分布规律。结果表明:作物整个生育期内,灌漠土无机氮以硝态氮为主,其含量是铵态氮的7.55倍。在玉米整个生育期内,与不施氮相比,75 kg(N)·hm?2、150 kg(N)·hm?2、300 kg(N)·hm?2和450 kg(N)·hm?2处理的土壤硝态氮含量分别增加29.7%、67.5%、88.2%和134.3%。与豌豆收获期相比,在玉米收获时土壤硝态氮含量平均降低44.2%。间作豌豆和间作玉米分别比对应的单作在0~120 cm土层硝态氮含量降低6.1%和5.1%。豌豆/玉米间作体系土壤无机氮累积量在不同施氮量和不同生育时期都是表层(0~20 cm)最高。豌豆收获后,0~60 cm土层土壤无机氮累积量间作豌豆和间作玉米分别比相应单作降低4.9%和1.9%,60~120 cm土层降低10.8%和9.2%;玉米收获后0~60 cm土层平均降低28.2%和9.4%,60~120 cm土层平均降低23.5%和12.5%。土壤无机氮残留量间作豌豆比单作豌豆在0~60 cm土层降低4.9%,60~120 cm降低10.9%。因此,施用氮肥显著增加了土壤无机氮含量和累积量,且主要影响土壤硝态氮。过量的氮肥投入会因作物不能及时全部吸收而被大水漫灌和降雨等途径淋洗到土壤深层,造成氮肥损失和农田环境污染。间作能显著降低土壤无机氮浓度和累积量,特别在作物生长后期对土壤无机氮累积的降低作用更加明显。  相似文献   

土壤高残留氮条件下施氮对夏玉米氮素平衡、利用及产量的影响   总被引：12，自引：4，他引：12  

石德杨  张海艳  董树亭 《植物营养与肥料学报》2013,19(1):38-45

土壤残留氮是不容忽视的土壤氮素资源.通过田间小区试验研究了土壤高残留氮下不同施氮量(0、80、160、240和320 kg/hm2)对夏玉米土壤硝态氮积累、氮素平衡、氮素利用及产量的影响,分析了夏玉米的经济效益.结果表明,土壤剖面硝态氮积累量随施氮量的增加而增加,且施氮处理硝态氮积累量显著高于不施氮处理;各施氮处理土壤硝态氮在0-60 cm土层含量最高,在0--180 cm剖面呈先减少后增加的变化趋势.不施氮处理夏玉米收获后土壤无机氮残留量高达378 kg/hm2,随施氮量的增加,无机氮残留和氮表观损失显著增加.作物吸氮量、氮表观损失量与总氮输入量呈显著正相关,总氮输入量每增加l kg作物吸氮量增加0.156 kg,而表观损失量增加0.369 kg,是作物吸氮量的2.4倍.高残留氮土壤应严格控制氮肥用量,以免造成氮素资源的大量浪费.夏玉米籽粒吸氮量随施氮量的增加呈增加的趋势,氮收获指数呈降低的趋势.氮肥农学效率、氮肥生理利用率、氮肥利用率和氮素利用率在施氮量80 kg/hm2时最高,随施氮量的增加降低;增施氮肥能降低高残留氮土壤中氮肥的增产效果和利用率.综合考虑产量、氮素利用和环境效应,N 80 kg/hm2是氮素高残留土壤上玉米的合理施氮量.  相似文献   

长期定位试验中氮肥与磷肥有机肥联合施用通过刺激根的生长增加玉米产量和养分吸收     

WEN Zhi-Hui  SHEN Jian-Bo  M. BLACKWELL  LI Hai-Gang  ZHAO Bing-Qiang  YUAN Hui-Min 《土壤圈》2016,26(1):62-73

Imbalanced application of nitrogen (N) and phosphorus (P) fertilizers can result in reduced crop yield, low nutrient use efficiency, and high loss of nutrients and soil nitrate nitrogen (NO₃^--N) accumulation decreases when N is applied with P and/or manure; however, the effect of applications of N with P and/or manure on root growth and distribution in the soil profile is not fully understood. The aim of this study was to investigate the combined effects of different N and P fertilizer application rates with or without manure on maize (Zea mays L.) yield, N uptake, root growth, apparent N surplus, Olsen-P concentration, and mineral N (Nmin) accumulation in a fluvo-aquic calcareous soil from a long-term (28-year) experiment. The experiment comprised twelve combinations of chemical N and P fertilizers, either with or without chicken manure, as treatments in four replicates. The yield of maize grain was 82% higher, the N uptake 100% higher, and the Nmin accumulation 39% lower in the treatments with combined N and P in comparison to N fertilizer only. The maize root length density in the 30--60 cm layer was three times greater in the treatments with N and P fertilizers than with N fertilizer only. Manure addition increased maize yield by 50% and N uptake by 43%, and reduced Nmin (mostly NO₃^--N) accumulation in the soil by 46%. The long-term application of manure and P fertilizer resulted in significant increases in soil Olsen-P concentration when no N fertilizer was applied. Manure application reduced the apparent N surplus for all treatments. These results suggest that combined N and P fertilizer applications could enhance maize grain yield and nutrient uptake via stimulating root growth, leading to reduced accumulation of potentially leachable NO₃^--N in soil, and manure application was a practical way to improve degraded soils in China and the rest of the world.  相似文献   

不同管理方式对夏玉米氮素吸收、分配及去向的影响   总被引：3，自引：5，他引：3  

徐明杰  张琳  汪新颖  彭亚静  张丽娟  巨晓棠 《植物营养与肥料学报》2015,21(1):36-45

【目的】本文利用15N同位素示踪技术探讨传统(CT)和优化(YH)两种管理方式对夏玉米氮素吸收、分配及去向的影响。分析目标产量下化肥氮的变化,解析夏玉米花前、花后氮素利用及转移规律,探讨肥料氮、土壤氮与作物氮之间的关系,为该地区夏玉米的科学合理施氮提供合理依据。【方法】在传统和优化两种管理方式定位试验中设置15N微区,采用将15N标记的尿素表施的方法,分析植株和土壤样品。新鲜土壤用1 mol/L KCl浸提,滤液用TRACCS 2000型流动分析仪测定土壤的NH+4-N和NO-3-N含量。15N标记的土壤和植物全氮的测定用烘干样(过0.15 mm筛),然后用美国THERMO finnigan公司生产的稳定同位素质谱仪DeltaplusXP进行测定。【结果】在该试验条件下,优化方式下夏玉米籽粒产量和总吸氮量显著高于传统方式,分别增加12%和10%。作物收获后,优化方式的15N吸收量及利用率显著高于传统方式,利用率分别为20.81%、32.54%。夏玉米各器官中氮素的积累量和向籽粒中的转移量土壤氮显著高于肥料氮,传统方式籽粒中氮素的57.73%、优化方式籽粒中氮素的45.15%来自各器官的转移,近一半的氮素是在花后积累的,基施高氮对作物生长作用不大。开花期土壤表层硝态氮含量传统方式显著高于优化方式,收获后有所降低,而土壤深层含量明显增加,有向下淋洗的趋势。夏玉米收获后,传统方式各土层的原子百分超均高于优化方式,而且在20—40 cm处出现了明显的15N累积峰,与开花期相比,40 cm以下土层的原子百分超明显增大,氮肥随水向下淋洗强烈。夏玉米收获后传统方式土壤氮素残留率高达56.18%,表现为土壤残留损失作物吸收;优化方式则表现为土壤残留作物吸收损失。【结论】在优化方式中夏玉米施氮量为N 185 kg/hm2时,玉米达到高产水平且氮肥的利用率高。适当减少施氮量及增加后期追肥次数可实现夏玉米的高产和肥料的高效利用。  相似文献   

Potato uptake and recovery of nitrogen 15N-enriched ammonium nitrate     

《Geoderma》2002,105(3-4):167-177

Tuber yield and nitrogen uptake in potatoes were recorded during 1996 and 1997 in Southern Bavaria. Recovery of applied fertilizer nitrogen was measured by using ¹⁵N (¹⁵NH₄¹⁵NO₃). Nitrogen fertilizer was brought out either broadcast or in the ridge; 150 kg N ha⁻¹ were applied either at planting or in split doses of 50 kg N ha⁻¹ (at planting, emergence and at 20-cm plant height). Due to unfavorable conditions, tuber yield and fertilizer N recovery were lower in 1996 as compared with 1997. Fertilizer N recovery in plant biomass (tuber and foliage) ranged from 35.9% to 68.5% at growth stage EC 79; the main fraction was allocated to tubers. Placement of fertilizer N in the ridge had a positive effect on N recovery, when the total N amount was applied at planting. In broadcast application, fertilizer N recovery was higher when the fertilizer doses were split, as compared with a single broadcast application at planting. When fertilizer N was applied in split doses, the effect of N placement became negligibly small. Fertilizer N recovery in soil ranged from 19.5% to 24.6%, and total recovery ranged from 60.1% to 88.0%. Rainfall between planting and plant emergence, and conditions restricting plant development in early developmental stages were related with unaccounted fertilizer N losses. Therefore, the positive effects of split N applications or fertilizer placement are most likely to occur under unfavorable growing conditions.  相似文献   

Uptake and translocation of nitrogen in patumma (Curcuma alismatifolia) by leaves or root     

Chamaiporn Anuwong  Takuji Ohyama  Kuni Sueyoshi  Norikuni Ohtake  Takashi Sato 《Journal of plant nutrition》2017,40(8):1204-1212

An adequate supply of nitrogen (N) is important for patumma growth and flower quality. This study aimed to compare the uptake and translocation of N by foliar and root application. Fertilization with ¹⁵ nitrate (NO₃)-N via roots or leaves was carried out at four stages, at the 1st to 4th fully expanded leaf (FEL) stages, and the plants were sampled at each successive stage. The uptake and translocation of ¹⁵N from foliar or root applications showed relatively similar patterns at all stages. Although the N fertilizer utilization rate by roots was higher than that via leaves, the foliar application stimulated reproductive growth by earlier flowering. The N supplied at the 1st FEL and the 2nd FEL was utilized mainly in leaves, whereas supplying N at the 3rd and 4th FEL promoted flower quality. Fertilizer application method and stage of application influence the utilization rate and translocation of N to the sink organs.  相似文献   

Fate of fertilizer nitrogen.   总被引：3，自引：0，他引：3  

D. BARRACLOUGH  E. L. GEENS  G. P. DAVIES  J. M. MAGGS 《European Journal of Soil Science》1985,36(4):593-603

Results are presented from a three year lysimeter investigation, employing single (¹⁵NH₄NO₃) and double (¹⁵NH₄¹⁵NO₃) labelled ammonium nitrate to study the uptake of soil and fertilizer nitrogen by cut ryegrass at 250, 500 and 900 kg N ha^?1 a^?1. Average annual recoveries of nitrogen were equivalent to 99,76 and 50% of the nitrogen added at 250, 500 and 900 kg N ha^?1, respectively. At 250 kg N ha^?1 the difference between the overall nitrogen recovery and the fertilizer recovery was almost entirely attributable to pool substitution resulting from mineralization/immobilization turnover (MIT). At 900 kg N ha^?1 both the low overall recovery of nitrogen and the low fertilizer recovery reflected the large excess of available nitrogen over crop requirements. No evidence of ‘priming’ was obtained. Analysis of the results from single and double labelled lysimeters using simultaneous equations indicated that at 250 kg N ha^?1,～70% of the nitrogen in the crop was derived from the ammonium pool. At 500 kg N ha^?1 this dropped to 64%, while at 900 kg N ha^?1 the figure was 59%. There was a suggestion that at the lower application rates, preferential uptake of ammonium was occurring but that as N supply exceeded crop requirements, nitrate was the major N source. Despite the preferential exploitation of the ammonium pool, at 250 and 500 kg N ha^?1 pool substitution resulting from MIT resulted in lower recoveries of fertilizer ammonium compared with fertilizer nitrate.  相似文献   

改善根系生长捕获深层土中NO3-N最优化免耕玉米氮肥利用率     

E. F. CAIRES  R. ZARDO FILHO  G. BARTH  H. A. W. JORIS 《土壤圈》2016,26(4):474-485

Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed to investigate the effect of gypsum application on the efficiency of N fertilizer in no-till corn(Zea mays L.) production in southern Brazil. A field experiment examined the effects of surface-applied gypsum(0, 5, 10, and 15 Mg ha~(-1)) and top-dressed ammonium nitrate(NH_4NO_3)(60, 120, and 180 kg N ha~(-1)) on corn root length, N uptake, and grain yield. A greenhouse experiment was conducted using undisturbed soil columns collected from the field experiment site to evaluate NO_3-N leaching, N uptake, and root length with surface-applied gypsum(0 and 10 Mg ha~(-1)) and top-dressed NH_4NO_3(0 and 180 kg N ha~(-1)). Amelioration of subsoil acidity due to gypsum application increased corn root growth,N uptake, grain yield, and N use efficiency. Applying gypsum to the soil surface increased corn grain yield by 19%–38% and partial factor productivity of N(PFPN) by 27%–38%, depending on the N application rate. Results of the undisturbed soil column greenhouse experiment showed that improvement of N use efficiency by gypsum application was due to the higher N uptake from NO_3-N in the subsoil as a result of increased corn root length. Our results suggest that ameliorating subsoil acidity with gypsum in a no-till corn system could increase N use efficiency, improve grain yield, and reduce environmental risks due to NO_3-N leaching.  相似文献