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1.
不同氮肥水平下早熟晚粳氮和磷的吸收利用特性及相互关系 总被引：6，自引：1，他引：5
采用大田试验,以长江中下游地区具有代表性的50个早熟晚粳品种为材料,研究7个氮肥水平(0、150.0、187.5、225.0、262.5、300.0、337.5 kg hm-2纯氮)下水稻氮和磷积累量、吸收速率、利用效率的差异及其相互关系。结果表明：(1)在0~337.5 kg hm-2纯氮范围内,随着氮肥水平的增加,早熟晚粳的植株含氮率和氮积累量在拔节、抽穗和成熟期均显著增加;植株含磷率和磷积累量在拔节和抽穗期显著增加,成熟期呈先增后减变化。(2)播种至拔节阶段氮和磷吸收速率随施氮量的增加而提高,差异极显著;拔节至抽穗阶段氮和磷吸收速率随施氮量的增加呈现先增加后降低的变化趋势;抽穗至成熟阶段的氮和磷吸收速率规律不明显。(3)在0~337.5 kg hm-2纯氮范围内,随着施氮量的增加氮素籽粒生产效率和磷素籽粒生产效率均显著降低,随着施氮量的增加基因型之间的差异减小;随着施氮量的增加氮和磷收获指数都呈现抛物线关系,在施氮量为262.0 kg hm-2纯氮时出现最大值。(4)早熟晚粳对氮和磷的吸收利用具有显著的协同效应,但随生育进程的推进这种效应减弱。水稻在播种至拔节、拔节至抽穗和抽穗至成熟3个生育阶段的氮和磷吸收速率都呈二次曲线关系(r=0.892**,r=0.736**,r=0.512**)。(5)相关分析表明,产量与拔节期、抽穗期和成熟期的吸氮量和吸磷量以及播种至拔节期和拔节至成熟期的吸氮速率和吸磷速率呈极显著正相关关系。增施氮肥有利于水稻氮和磷吸收利用的提高,但氮肥过高时氮和磷吸收利用不再增加,甚至有所降低。 相似文献
2.
为探明贵州地区糯高粱氮肥高效利用的施肥技术,以品种红缨子为研究对象,设置0（N0）、120（N120）、240（N240）、360（N360）、480（N480）、和600kg/hm2（N600）6个施氮水平,研究了糯高粱的产量和氮素吸收利用特征。结果表明,糯高粱产量、干物质积累总量和氮素积累总量随氮素水平的提高呈先升高后降低的趋势,增施氮素较不施氮素能够显著提高糯高粱的产量、干物质积累总量和氮素积累总量,其中以N240处理增幅最大,较N0处理分别增加28.87%、35.83%和49.62%。随着施氮量的增加,糯高粱氮素表观回收率、氮肥农学利用率、氮肥利用率、氮肥偏生产力和产投比呈下降趋势。利用二次多项式和平方根模型分别拟合糯高粱产量和效益的施氮效应,当施氮量分别为294.5和252.6kg/hm2时产量最高,施氮量分别为168.2和132.7kg/hm2时效益最大。兼顾产量、效益及氮肥利用效率,120~240kg/hm2的氮肥施用量是适宜的。 相似文献
3.
In intensive farming systems, farmers split up and apply the N fertilization to winter cereals and oilseed rape (OSR) at several dates to meet the need of the crop more precisely. Our objective was to determine how prior fertilizer N application as slurry and/or mineral N affects contributions of fertilizer‐ and soil‐derived N to N uptake of barley (1997), oilseed rape (OSR; 1998) and wheat (1999). In addition, residual fertilizer N effects were observed in the subsequent crop. Since autumn 1991, slurry (none, slurry in autumn, in spring, in autumn plus in spring) and mineral N fertilizer (0, 12 and 24 g N m−2) were applied annually. Each year, the treatments were located on the same plots. In 1997–1999, the splitting rates of the mineral N fertilization were labelled with 15N. Non‐fertilizer N uptake was estimated from the total N uptake and the fertilizer 15N uptake. All three crops utilized the splitting rates differently depending on the time of application. Uptake of N derived from the first N rate applied at the beginning of spring growth was poorer than that from the second splitting rate applied at stem elongation (cereals) or third splitting rate applied at ear emergence or bud formation (all three crops). In contrast, N applied later in the growing season was taken up more quickly, resulting in higher fertilizer N‐use efficiency. Mineral N fertilization of 24 g N m−2 increased significantly non‐fertilizer N uptake of barley and OSR at most of the sampling dates during the growing season. In cereals, slurry changed the contribution of non‐fertilizer N to the grain N content only if applied in spring, while OSR utilized more autumn slurry N. In OSR and wheat, only small residual effects occurred. The results indicate that 7 years of varying N fertilization did not change the contribution of soil N to crop N uptake. 相似文献
4.
氮肥水平对不同育种时代粳稻产量、氮素吸收利用差异的影响 总被引：27，自引：0，他引：27
以选育时期不同(两个选育时代)的12个水稻品种为材料,于施氮量为0,225,300 kg/hm~2纯氮大田条件下,研究了不同氮肥水平下两选育时代的水稻品种产量、物质生产积累量及氮素吸收、利用效率的差异.结果表明,水稻产量随着选育时代的更替有所提高,并随施氮量的增加两时代产量表现不同,早期品种中有83.3%的水稻基因型的产量随施氮量增加呈增加趋势,当代品种产量则有一半基因型在225 kg/hm~2氮肥水平下产量达最大,说明早期品种对氮肥反应较当代品种敏感.农艺性状中的株高和穗长随着育种时代的更替有矮化和减小的趋势,着粒密度有所增加.干物质和氮素平均积累量在生育时期各阶段均表现为当代品种大于早期品种,氮素利用效率亦表现相同的规律.相关分析表明,水稻产量与抽穗、成熟期物质积累量和氮素吸收量均呈显著或极显著正相关关系,与拔节期关系不密切.氮素利用效率与产量呈显著正相关,与株高和穗长呈显著负相关.说明随着选育时代的更替,水稻产量、吸氮量及氮素利用效率有所提高,株型趋于矮化,穗型由散穗向密穗型演变. 相似文献
5.
为构建水稻高产高效节水栽培技术模式,通过大田小区试验,研究了在节水灌溉条件下施氮量和栽植密度对双季晚稻丰源优299肥料利用率的影响。结果表明：施氮量、栽植密度及氮密互作对水稻氮磷钾素吸收和肥料利用率的影响均显著。随着施氮量的增加,水稻植株氮素与磷素吸收量呈先增长后减少的趋势,吸钾量呈现出先增加后减少再增加的趋势。随着密度的增加,植株总吸氮量与总吸钾量呈现先降低后升高的趋势,总吸磷量呈现逐步增加的趋势。低氮处理的氮肥贡献率、土壤氮素依存率、氮肥农学利用率和氮肥偏生产力最高,显著高于中氮处理;高密处理提高了氮肥吸收利用率和氮肥贡献率。水稻经济产量与茎叶氮磷钾素吸收量呈极显著正相关,与氮肥贡献率呈极显著正相关。因此,合理的施氮量和栽植密度组合（N1T3）能够形成水稻高产高效的群体结构,提高肥料利用率,进而提高水稻生产效益。 相似文献
6.
典型玉米自交系氮素吸收利用特点的研究 总被引：1，自引：0，他引：1
在大田条件下,对8个代表性的玉米自交系在不同施氮水平下的氮素吸收与利用特点及与氮效率相关的一些性状进行了研究。结果表明：玉米自交系在产量、生物量和氮累积量上存在显著的差异。通过玉米自交系各性状与氮效率的关系的分析表明,低氮胁迫下,应选择抽丝期穗位叶叶绿素含量高、穗位叶叶面积大、籽粒含氮量高和氮收获指数大的自交系,高氮处理条件下,应选择抽丝期生物量大和成熟期生物量大的自交系。通径分析表明,氮吸收和氮利用效率对氮效率的作用均是直接作用大于间接作用。3个施氮水平条件下,对氮效率的直接作用是氮吸收效率大于氮利用效率。在低氮条件下,氮吸收效率的直接作用更强,而氮利用效率对氮效率的直接作用是随着施氮量的增加逐渐增强。在氮2、氮3处理中,吸收效率和利用效率的共同影响导致了产量差异,并且是吸收效率的影响较大;高氮处理则主要是吸收效率的影响。 相似文献
7.
水肥一体肥料减量对大棚番茄产量、品质和氮肥利用率的影响 总被引：10，自引：1，他引：9
针对安徽省设施番茄生产中肥料施用量大、施肥方法不科学等问题,以安徽省芜湖县设施番茄为研究对象,探讨水肥一体化措施下减量施肥对番茄产量、产值、品质、养分吸收和氮肥利用效率的影响,以期为区域设施番茄合理水肥管理提供理论和技术支持。研究结果表明：与菜农习惯水肥管理相比,水肥一体氮肥减量20%-40%或氮磷钾肥各减量20%都能够提高番茄产量、产值和利润;影响番茄品质因子较多,在本试验施肥量下,水肥一体减量施肥番茄可溶性总糖、可溶性固形物含量下降,Vc含量增高,适当减少肥料用量有利于番茄红素含量的提高,减肥幅度过大,番茄红素含量下降;水肥一体减量施肥能提高氮肥当季利用率。综合番茄产量、品质和氮肥利用效率,在本试验条件下, N 240kg/hm2、P2O5 144 kg/hm2、K2O 240 kg/hm2 是较为合适的用量。笔者认为,尽管优化施肥、水肥一体化减量施肥能提高氮肥利用效率,但设施番茄的氮肥利用率仍较低,氮肥利用率的提高仍有一定的潜力。 相似文献
8.
U. R. Pal B. A. Kalu J. C. Norman D. K. Adedzwa 《Journal of Agronomy and Crop Science》1988,160(2):132-140
Field experiments were conducted to investigate into the N and P fertilizer use in soybean/maize mixture during the wet seasons of 1985 and 1986 at Yandev Agricultural Experiment Station. Soybean/maize mixtures with 2/3 of the respective plant population of both crops in pure stands were raised at factorial combinations of four rates of N, 0, 40, 80, and 120 kg N/ha and four rates of P, 0, 13.2, 26.4 and 39.6 kg P/ha in a randomized complete block design with three replications.
The grain yield of maize cv. TZB (a pure line variety) in mixture and land equivalent ratio (LER) increased linearly up to 120 kg N/ha in 1985 as against significant increase in the grain yield of maize cv. 8322–3 (a hybrid variety) and LER up to 40 kg N/ha only in 1986 primarily due to greater fertilizer N recovery by the latter. Significant enhancement in LER was also recorded up to 26.4 kg P/ha in both years. The yield of soybean in mixture remained unaffected by N or P rates.
Total N uptake by shoots of soybean/maize mixture was significantly and linearly increased up to the application of 120 kg N/ha in 1985 as against significant increase in total N uptake by soybean/maize mixture only up to 40 kg N/ha in 1986 owing to the greater fertilizer N recovery by maize (69%) in the latter than the one (29.75—31.75%) in the former. Total N uptake by shoots of soybean/maize was also increased significantly due to the application of 26.4 kg P/ha.
Application of N and P also significantly enhanced P uptake by shoots of soybean/maize mixture and fertilizer P recovered by mixture was less (3.99—12.95%) in 1985 than the one (19.95—32.12%) in 1986. 相似文献
The grain yield of maize cv. TZB (a pure line variety) in mixture and land equivalent ratio (LER) increased linearly up to 120 kg N/ha in 1985 as against significant increase in the grain yield of maize cv. 8322–3 (a hybrid variety) and LER up to 40 kg N/ha only in 1986 primarily due to greater fertilizer N recovery by the latter. Significant enhancement in LER was also recorded up to 26.4 kg P/ha in both years. The yield of soybean in mixture remained unaffected by N or P rates.
Total N uptake by shoots of soybean/maize mixture was significantly and linearly increased up to the application of 120 kg N/ha in 1985 as against significant increase in total N uptake by soybean/maize mixture only up to 40 kg N/ha in 1986 owing to the greater fertilizer N recovery by maize (69%) in the latter than the one (29.75—31.75%) in the former. Total N uptake by shoots of soybean/maize was also increased significantly due to the application of 26.4 kg P/ha.
Application of N and P also significantly enhanced P uptake by shoots of soybean/maize mixture and fertilizer P recovered by mixture was less (3.99—12.95%) in 1985 than the one (19.95—32.12%) in 1986. 相似文献
9.
缓控释肥料应用于我国水稻生产中,对化肥使用量零增长和农业可持续发展具有重要推动作用。本研究以连续在湖南进行6年(2013—2018年)的双季稻控释尿素施用试验为研究平台,分析控释尿素施用下环洞庭湖区早晚稻主要生育期地上部氮素累积、氮素阶段吸收速率与氮素利用的关系,探究控释尿素减施对水稻持续稳产增产的原因。结果表明:早稻各施氮处理均有1次明显的氮素阶段吸收速率峰值,控释尿素(controlled-release urea,CRU)处理氮素吸收相对延后,氮素累积主要在幼穗分化始期至抽穗期阶段,占生育期总量的35.31%~42.33%,其次为始分蘖期至幼穗分化始期和抽穗期至乳熟期。晚稻于始分蘖期至幼穗分化始期和抽穗期至乳熟期出现2次明显的氮素阶段吸收速率峰值,均以1.0 CRU(等氮量控释尿素)处理峰值最高;始分蘖期至幼穗分化始期、抽穗期至乳熟期水稻大量吸收氮素,累积增量分别占35.92%~40.52%和23.05%~24.58%。控释尿素还能显著提高双季稻产量,早晚稻分别以0.9 CRU(控释尿素减氮10%)和0.8 CRU(控释尿素减氮20%)处理最佳,控释尿素减施的晚稻增产效果优于早稻,且显著提高早晚稻氮肥吸收利用率、农学利用率和偏生产力。CRU处理早晚稻产量与幼穗分化始期、抽穗期、乳熟期、腊熟期氮素累积量和有效穗数均呈极显著正相关,且晚稻产量与穗长呈显著正相关;早晚稻幼穗分化始期氮素累积量与氮肥农学利用率、生理利用率呈显著负相关,氮肥偏生产力与早稻幼穗分化始期、抽穗期、乳熟期和腊熟期氮素累积量呈极显著或显著负相关,与晚稻抽穗期氮素累积量呈显著负相关。因此,控释尿素施用使水稻氮素阶段吸收速率、地上部氮素累积后延,有利于后期生殖生长及籽粒结实,显著提高双季稻产量及氮肥利用效率。结合双季稻吸氮特征和籽粒产量,建议环洞庭湖区早稻采用释放期较短的控释尿素或配合速效氮肥施用,进一步实现增产。 相似文献
10.
A lysimeter study was conducted to investigate how nitrogen uptake of spring wheat and oats and N leaching losses are differing when either oilseed rape or faba bean are grown as green manure. The experiment was conducted during 1982–1988, and fertilizer applied to the cereals was either farmyard manure, FYM, (6 and 12 g N/m2 /year) or mineral fertilizer, MiF, at a rate of 6 g N/m2 . On average of the 7 year period faba bean increased N uptake of the cereals fertilized with FYM at harvest by 3–4 g/m2 . Differences between the two application rates were negligible. N-leaching losses increased twofold when faba bean was grown instead of oilseed rape. Growing faba bean after cereals supplied with MiF, too, increased N uptake of the cereals and significantly increased leaching losses. 相似文献
11.
乙烯利和氮肥对夏玉米氮素吸收与利用及产量的调控效应 总被引：3，自引：0，他引：3
以玉米品种"郑单958"为材料,在大田条件下,研究了乙烯利(0和180 g hm–2)和氮肥水平(0、75、150和225kg N hm–2)对夏玉米产量、氮素吸收和利用以及SPAD值的影响。结果表明,乙烯利处理显著降低了氮吸收量和吸收效率,但显著提高氮利用效率,其中乙烯利处理氮农学效率比对照提高了32.7%~34.6%,而且乙烯利处理对玉米产量及其产量构成因素没有显著影响;随着施氮量增加,夏玉米产量、产量构成因素和氮吸收量显著增加,而氮吸收效率、氮利用效率、氮偏生产力和氮农学效率随之降低,其中225 kg N hm–2处理氮吸收量比0 kg N hm–2处理提高了68.4%~91.8%,但225 kg N hm–2和150 kg N hm–2处理之间的氮吸收量差异不显著。乙烯利和氮肥对氮吸收量、氮吸收效率和氮农学效率具有互作效应。喷施乙烯利和增施氮肥均能提高灌浆期穗位叶SPAD值,但两者之间没有互作效应。通过相关性分析表明,夏玉米产量与吐丝期氮吸收量、收获期氮吸收量、灌浆期穗位叶SPAD值显著正相关。 相似文献
12.
The effect of N fertilizer rates and time of N application on plant growth, N %, N uptake, smut index and yield response of corn were investigated in the field during the summer seasons 1988 and 1989. Increasing N rate from 30 to 60 and/or 90 kg/acre produced greater response on the studied parameters, followed by a limited response at 120 kg N/acre. Opposite results were detected on yield losses, owing to the severity of smut infection. Single application of N at planting was the least productive for DM and grain yields, compared with 2-split or 3-split N treatments. On the other hand, splitting N application at planting and 16-leaf growth stages produced limited smut infection with greater increase in grain yield and lowest DM and N accumulations. The results also showed that 3-split N treatment acted to accelerate the vigour growth and N uptake to a greater extent, creating more favourable conditions for stimulating smut infection, with an attendant increase on yield losses. Because of the advantage of applying 90 kg N/acre over the N treatments on the measured parameters, with particular reference to yield potential and smut performance, attention was given to splitting N fertilizer at planting and 16-leaf growth stages. 相似文献
13.
减氮配施控释尿素对冬小麦产量及氮肥效率的影响 总被引：7，自引：1，他引：6
为探究冬小麦科学施氮技术,采用田间试验研究了推荐施肥全量施氮(196 kg N/hm2)和减氮20%(156.8 kg N/hm2)条件下,不同控释尿素与普通尿素配比对冬小麦产量及氮素吸收利用的影响。结果表明：施氮显著增产17.11%~27.39%,推荐施肥较农户施肥增产2.14%~8.77%。减氮20%产量与全量氮无显著差异。等氮条件下,施用控释尿素的氮肥利用率均高于普通尿素,且减氮处理均高于全量氮处理。施氮156.8 kg/hm2 （75%控释尿素+25%普通尿素）产量较农户施肥增产6.60%,氮肥利用率较经验施肥和全量普通尿素提高13.64 和9.22 个百分点,氮肥农学效率增加2.29 和1.44 kg/kg。施氮156.8 kg/hm2（75%控释尿素+25%普通尿素）一次性基施对豫北地区冬小麦具有较好的增产效果,氮肥效率较高。 相似文献
14.
研究基肥施氮量对甘蔗苗期氮素吸收与利用的影响,以期为甘蔗生产合理施用氮肥提供参考依据。以‘新台糖22号’（ROC22）为试材,采用网室微区盆栽试验方法,设基肥施用15N标记的尿素5 g/盆、2.5 g/盆及1.5 g/盆3个处理。结果表明,苗期甘蔗全氮含量、干物质积累量、从肥料中吸收的氮素总量及土壤碱解氮和硝态氮含量均随氮肥施用量的增加而显著提高,但氮肥利用率却随氮肥施用量的增加而显著下降;施氮量明显影响氮素在甘蔗植株体内及不同土层的分布;苗期甘蔗主要吸收20~40 cm尤其是20~30 cm土层的氮素。甘蔗基肥施用氮肥应考虑适宜的量和土层深度。 相似文献
15.
F. X. Maidl A. Panse J. Dennert R. Ruser G. Fischbeck 《European Journal of Agronomy》1996,5(3-4):247-257
The effects of N rates and N timings on yield formation, N uptake at five growth stages and fertilizer N use efficiency of six-row and two-row winter barley were evaluated in field trials conducted from 1990/91 to 1992/93 at the TU Munich's research station Roggenstein.
On average over 3 years the six-row cultivar yielded most at a total rate of 110 kg ha−1 N including an early application of 40 kg ha−1 N up to EC 30 (Zadoks scale). The two-row cultivar achieved maximum yield at a total rate of 140 kg ha−1 N including early applications of 70 kg ha−1 N up to EC 30. The highest yielding N-treatments of six-row barley regularly took up less nitrogen at EC 32 (95 kg ha−1 N on average) than the non-optimally fertilized treatments, whereas full exploitation of the yield potential of two-row barley was associated with higher rates of N-uptake at EC 32 (113 kg ha−1 N on average).
Lodging did not occur in the trials conducted in 1991 and 1992 and no difference was detected between the two cultivars in fertilizer N use efficiency. With six-row barley the N treatment giving maximum yield also led to an optimum fertilizer N use efficiency. Full exploitation of the two-row barley yield potential was associated with suboptimal fertilizer N use efficiencies. 相似文献
16.
江苏滨海盐碱地麦后直播棉氮、磷、钾肥料优化配比研究 总被引：4，自引：0，他引：4
【目的】建立江苏省滨海盐碱地麦后直播棉合理的施肥技术体系。【方法】2017―2018年在江苏省滨海棉田,以中棉所50为材料,采用正交设计,研究了不同氮、磷、钾肥配施量对棉花生物量、养分累积与利用及产量的影响。【结果】氮、磷、钾肥3因子对棉株地上部和生殖器官生物量、棉株地上部氮和钾素累积量及皮棉产量的影响均为氮肥>磷肥>钾肥。施N 150~225 kg·hm-2、P2O575 kg·hm-2下棉株地上部和生殖器官生物量、氮和钾累积量及皮棉产量较高。钾肥因子对生殖器官生物量和皮棉产量影响不显著。钾肥因子对氮、钾素利用效率的影响大于氮肥和磷肥,氮肥因子对磷素利用效率的影响大于磷肥和钾肥,施K2O 75~150 kg·hm-2氮、钾素利用效率较高、施氮225 kg·hm-2磷素利用效率较高。土壤碱解氮、速效磷、速效钾含量较高棉田的氮、磷(P2O5)、钾(K2O)肥配施量分别为225 kg·hm-2、75 kg·hm-2和150~225 kg·hm-2。相关分析表明,皮棉产量与棉株氮、钾素累积量显著正相关。【结论】长江流域棉区滨海盐碱地麦后直播棉利于产量和养分利用效率提高的最佳氮、磷(P2O5)、钾(K2O)肥配施量分别为225 kg·hm-2、75 kg·hm-2、75 kg·hm-2。 相似文献
17.
缓释氮肥通过相对缓慢释放肥效,具有增强植株氮素吸收利用和产量形成的效果。本研究通过设置不同缓释尿素配施处理大田试验,研究了等氮条件下不同缓释尿素配比处理对夏玉米氮素吸收和产量性状的影响。结果表明,与未施肥对照(CK)相比,普通氮素常规处理(T1)和配施缓释尿素处理(T2~T5)的硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性、植株干物重、氮累积量和吸收速率、产量构成因素、产量和氮肥利用效率均显著提高。与T1相比,T2~T5拔节期和大口期的NR和GS活性、植株干物重、氮累积量和吸收速率氮降低,但吐丝以后的各时期NR和GS活性、植株干物重、氮累积量和吸收速率增高。不同缓释尿素配施处理(T2~T5)相比,各生育时期的NR和GS活性随缓释尿素用量增多也随之增高；植株干物重、氮累积量在拔节和大口期表现为随缓释尿素用量增多也随之增大、在吐丝、灌浆和成熟期表现为随缓释尿素用量增多呈单峰曲线,大体以T3峰值最高。随缓释尿素用量增多,灌浆至成熟植株的氮累积量和氮吸收速率增大。与T1相比,T2~T5处理的穗粒数、千粒重和产量提高,以T3(50%缓释尿素底施+50% N尿素大口追施)的产量增幅最大。此外,配施缓释尿素处理T3和T4,成熟期收获指数和氮肥利用效率较常规尿素处理T1也明显提高。研究表明,以适当比例缓释尿素(50%总氮)底施配合常规尿素(50%总氮)大口追施,能协调植株各生育时期氮素需求,促进植株氮素吸收、利用,改善产量的形成能力。 相似文献
18.
Model trials on the uptake of soil and fertilizer nitrogen from various depths by spring wheat The uptake of ammonium nitrogen by spring wheat mixed into various soil depths was investigated in a pot trial using 1-m high soil columns. At the same time a nitrification inhibitor (NI) was used in some of the variants in order to study the utilization of fertilizer N under the conditions of a temporary inhibition of nitrification. In order to monitor the interrelationships of soil and fertilizer N, 15 N-labelled ammonium sulphate was used. The following results were obtained.
- 1 The various depths at which the N was located were not found to affect yields; nor did the use of the NI have any influence.
- 2 There was a statistically significant increase in the N content of the grains as the N was mixed with deeper layers of the soil; this was at a lower level in the series with NI. In straw no change was observed in the series without NI, there being a decrease of the N content in the series with NI.
- 3 The utilization of fertilizer N according to the “difference method” was between 76 % and 84 % in the series without NI with an increasing tendency of the nitrogen located at deeper levels. In the series with NI there was a reverse tendency of 74 % to 69 %. According to the 15N method only 54–62 % of the fertilizer N was used by the plants. The NI scarcely changed the utilization. Overall there was not a significant higher use of the nitrogen in the deeper layers.
- 4 In the fertilized series more soil N was mobilized and taken up by the plants than in the control. This effect was more pronounced in the series with no NI.
- 5 The mobilization of soil N by fertilizer N (“priming effect”) contrasted with a more vigorous immobilization of fertilizer N. This resulted in an overall positive soil N balance.
- 6 A total of about 30 % of the fertilizer N remained in the soil. Most of it was to be found in the incorporation layer. However, displacement into the neighbouring layers did take place, this being more pronounced in the acropetal direction in the case of the N in the deeper layers than in the basipetal direction in the case of the N introduced into the top layer.
19.
滴灌水肥一体化下施氮量对小麦氮素吸收及土壤硝态氮含量的影响 总被引：6，自引：0，他引：6
为探明华北地区山前平原水肥一体化条件下小麦合理的氮肥运筹。于2013-2015年2个小麦生长季,设置4个滴灌施氮量(N0-不施氮、N1-120 kg/hm~2、N2-240 kg/hm~2、N3-360 kg/hm~2)处理,研究滴灌水肥一体化下施氮量对小麦氮素吸收积累和土壤硝态氮含量的影响。结果表明:施氮量N1、N2和N3处理的小麦干质量及产量较处理N0显著增加,N1、N2和N3处理间无显著差异;施氮量对小麦茎秆的氮含量影响较大,但对籽粒氮含量的影响差异不显著;处理N3的小麦总吸氮量分别显著高于处理N0、N1和N2,但处理N1和N2之间无显著差异;氮肥收获指数以N2处理最高,氮肥当季回收利用率、氮肥农学效率、氮肥生产效率和氮肥利用效率均表现出随施氮量增加而降低的趋势;施氮量超过240 kg/hm~2,土壤硝态氮含量增加,且随种植年限的延长更加明显。采用一元二次方程拟合,获得小麦最高产量的施氮量为238.46~250.78 kg/hm~2,经济施氮量为174.28~207.18 kg/hm~2。综合考虑经济效益和生态效益,该条件下小麦滴灌经济施氮量以174~207 kg/hm~2为宜。 相似文献
20.
云南植烟土壤肥料利用率研究 总被引：7，自引：2，他引：5
通过对云南不同烟区植烟土壤肥料利用率进行试验研究,结果表明：不同植烟土壤的N、P、K肥利用率存在差异,以昆明水稻土和文山红壤的N、P、K肥料利用率较高;不同土壤类型及质地差异与肥料利用率之间也存在差异,质地粘重的肥料利用率较低,如曲靖黄壤平均只有15.54%;壤土的肥料利用率较高,如文山红壤平均达到38.28%;肥料利用率与土壤养分含量呈负相关,土壤养分含量高则肥料利用率低,反之亦然。红壤的N肥利用率较高（73.63%）,黄壤较低（31.70%）,水稻土和紫色土居中,为50%~60%之间,平均为54.71%,故土壤养分含量高,其肥料的利用率低。通过研究,以期为烤烟大面积生产施肥提供参考。 相似文献