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用15N示踪技术研究了节水灌溉条件下冬小麦对不同施氮量的氮素吸收和氮素平衡 ,并比较了两种灌溉制度下小麦对节肥施氮量的吸收动态。结果表明 ,与常规施氮量处理相比 ,节水灌溉条件下节肥施氮量处理的氮肥损失率降低 ,氮肥当季利用率和土壤残留率提高 ;基施氮肥的利用率高于追施氮肥 ;土壤肥料氮的残留率在 2 9%～ 41 %之间 ,分布于 1m土层中 ,其中60 %以上集中在 0～ 2 0cm土层 ;在整个小麦生长季内 ,肥料氮并没有淋洗到 1 30m以下。节肥施氮量在常规灌溉下的当季利用率比在节水灌溉下降低 1 6 6%。 相似文献
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15N示踪法研究弱光对不同穗型冬小麦氮素积累和转运的影响 总被引：1，自引：0，他引：1
在大田试验条件下,采用15N示踪法,设置不遮光(T0)、开花后1～10d遮光(T1)、开花后11～20 d遮光(T2)和开花后21～30 d遮光(T3)4个处理,每个处理设置15N尿素作底肥+普通尿素作追肥和普通尿素作底肥+ 15N尿素作追肥两个15N示踪的微区,研究灌浆期弱光条件下不同穗型小麦品种对不同来源氮素的吸收、分配、转运和氮素利用效率的影响.结果表明,灌浆期不同阶段遮光均不利于植株对氮素的吸收、积累和转运,品种间表现一致,呈T0 ＞T3 ＞T2 ＞T1规律;小麦植株吸收的氮素68.0 ％～71.39％来自土壤氮,对追施氮的吸收量大于底施氮,灌浆期遮光增加了土壤氮素在营养器官的分配比例,不利于营养器官中土壤氮素向籽粒中的转运;各处理籽粒产量、肥料氮吸收量、氮肥利用率和肥料偏生产力均表现为T0 ＞T3＞ T2 ＞T1.相同处理条件下,济麦22籽粒产量和对肥料的利用大于山农8355.小麦灌浆期阶段性遮光降低了植株对氮素的吸收、转运和籽粒产量,以灌浆前期遮光影响最大,中期次之,后期最小;相同遮光条件下济麦22的籽粒产量和氮素利用率较高. 相似文献
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塑料簿膜覆盖下棉花氮素营养特性及增产效果 总被引：1，自引：0，他引：1
本试验应用~(15)N标记硫铵研究塑料薄膜覆盖下直播棉花的氮素营养特性及其增产效果。试验表明:盖膜棉花吸收的总氮量明显高于不盖膜处理,苗期尤为突出,盖膜棉株的总氮量为不盖膜处理的244—267%。盖膜并施肥不仅增加了棉株对土壤氮和肥料氮的吸收利用,而且,通过营养器官输往生殖器官的肥料氮量与土壤氮量也分别比不盖膜处理高50.5%和157%,初花期追肥,于初花—盛花阶段形成了吸收肥料氮的高峰,在棉株吸自肥料的氮素中有63.3—76.6%是在这一阶段吸收的。盖膜棉花对氮肥的当季利用率为36%,比不盖膜处理高9%。盖膜施肥处理棉花的产量最高,每公顷产籽棉2472公斤。 相似文献
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甜椒对不同形态氮素的吸收和分配 总被引：6，自引：0，他引：6
甜椒对不同形态氮素的吸收利用有显著差异。幼苗期及发棵期ＮＨ ＋４ Ｎ 对生长有利,而盛果期则以ＮＯ－３ Ｎ 有利。同种形态氮素因施用时期不同而氮素利用率差异很大,以盛果期追肥利用率最高,为４１８ ％ ～４５８ ％ ; 基肥利用率为３３６ ％ ～３６７ ％ 。不同时期施肥的肥料氮在各器官的分配不同,基肥及初花期施肥氮素主要流向茎叶,占总吸收量的７５ ％ 左右;盛果期追肥以果实分配较多,占总吸收量的６０ ％以上。对植株氮素来源的分析表明,仅４００ ％ ～４１５ ％ 的氮素来自于肥料,而近６０ ％ 的氮素来自于土壤。 相似文献
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氮磷复(混)合肥料的氮素肥效 总被引：1，自引：0，他引：1
研究复合肥料中氮素的利用率、残留率、损失率、肥效和残效表明:在作基肥施用的条件下,复(混)肥料对春小麦籽粒的增产效果相同。春麦对肥料氮素的吸收利用取决于氮素的形态,尿素磷铵中的铵态氮利用率为35.0％,硝酸磷铵普钙中的铵态氮为31.4％,尿素磷铵中的尿素氮为28.1％,硝酸磷铵普钙中的硝态氮为24.8％。硝酸磷铵普钙中的硝态氮具有最高的土壤残留率(48.9％),尿素磷铵中的铵氮损失率最低(22.7％)。不同复(混)合肥均有明显残效,水稻的籽粒产量都高于对照,不同复(混)合肥之间差异不明显。水稻对残留氮的利用率不同复(混)合肥之间的差异也不明显。 相似文献
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不同水分和氮肥水平对冬小麦吸收肥料氮的影响 总被引：5，自引：0，他引：5
田间微区条件下用15N研究了不同水分和氮肥水平对冬小麦氮素吸收及化肥氮的去向。结果表明 ,4次灌水省肥处理的全氮吸收量高于节水省肥处理 ,节水常规施肥量处理的全氮吸收量高于省肥处理 ,但小麦籽粒氮素收获指数降低。 4次灌水处理的肥料氮损失率提高 ,氮肥当季利用率和土壤残留率均低于 2次灌水的相应氮肥处理。同一水分条件下 ,常规施肥量处理的氮肥当季利用率和土壤残留率低于省肥处理 ,损失率提高。等量氮肥不同施肥方法间的比较 ,全部基施处理的损失率下降 ,肥料氮回收率高于分次施肥处理 相似文献
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甘薯对不同形态氮素的吸收与利用 总被引：11，自引：2，他引：9
为探讨氮素形态对甘薯氮素吸收、利用及其氮素生产效率的影响。在大田生产条件下,分别施用酰胺态氮、铵态氮和硝态氮肥料,研究了甘薯生长发育过程中吸收根活力变化和氮素吸收动态、收获期氮素积累量和分配以及块根产量。结果表明,与酰胺态氮处理相比,铵态氮和硝态氮处理的吸收根活力和氮素积累起始势较高,氮素积累量、肥料氮素利用率及其生产效率也较高,块根产量提高了16.37%和10.52%。与硝态氮处理相比,铵态氮处理的氮素积累量较低,肥料氮素在块根中的分配比例较高,块根产量、氮素生产效率和肥料氮素生产效率分别提高了5.30%、13.28%和5.29%。甘薯施用铵态氮肥有利于高产和高效。 相似文献
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应用~(15)N 示踪法研究我省棉区棉、麦(豆)套种对氮肥合理施用中某些因子的影响。结果表明:在棉、麦套种栽培中,处于生育后期的小麦,对于麦行间施给棉花底肥、苗肥的氮素,仍能分别吸收利用17.5%和2.5%,而且所吸收的养分中,90%以上底肥氮和50%以上苗肥氮转运到穗部;在前茬小麦每亩施氮10斤的情况下,小麦因吸收了棉花底肥中的氮素而增产,但对当季棉花产量无明显影响;因所吸苗肥氮量很少,对小麦无增产作用。在棉豆(蚕豆)套种中,由于蚕豆的固氮作用,对棉花的底肥、苗肥吸收利用很少,仅为3.4%,是小麦吸收量的1/4,可见蚕豆基本不与棉花争氮。在后作棉花施用等量氮情况下,豆茬花(蚕豆不施肥)比麦茬花(小麦每亩施氮10斤)平均增产9.17%。本文还阐述了麦棉两熟中,前后作施肥的相互影响。 相似文献
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Tariq Mahmood Rehmat Ali Zahid Latif Wajid Ishaque 《Biology and Fertility of Soils》2011,47(6):619-631
Using an alkaline calcareous soil, experiments were conducted to elucidate the effects of nitrification inhibitor dicyandiamide
(DCD) on the fate of 15N-labelled urea applied to cotton, maize, and wheat under greenhouse conditions. Combined effects of DCD and two levels of
wheat straw (applied to cotton) and of fertilizer application method (conventional broadcast vs. point injection in maize
and wheat) on the recovery of the fertilizer N were also studied. High soil temperatures prevailed under cotton and maize,
whereas the soil temperature was relatively moderate during the wheat growing season. The fertilizer N loss under cotton was
lowest (44% of the applied) when urea was applied alone; the loss increased due to DCD (54%) or wheat straw (50–54%) and was
highest (63–64%) when DCD and wheat straw were applied together. Under maize also, DCD increased the loss of the fertilizer
N applied by the conventional method (51% without DCD vs. 66% with DCD) or by point injection (26% without DCD vs. 42% with
DCD). With the conventional method under wheat, DCD had no effect on the fertilizer N loss (34–37% of the applied). The fertilizer
N loss under wheat was least (16%) when urea solution was point-injected but increased (24–26%) due to DCD or/and when pH
of the urea solution was reduced to 2. Besides, DCD significantly reduced the fertilizer N uptake and increased the fertilizer
N immobilization in soil under cotton and maize. However, DCD applied in combination with a higher level of wheat straw significantly
increased the cotton dry matter and N yields due to increased N availability from sources other than the fertilizer. The results
suggested that the use of DCD may not be beneficial in alkaline calcareous soils and that point injection of urea solution
without any amendment is more effective in conserving the fertilizer N as compared to the conventional broadcast method. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(18):2385-2396
Cotton–wheat is the second most important cropping system after rice–wheat in India and Pakistan, and is practiced on about 4.02 mha. By 2010, more than 6 million Indian farmers had adopted transgenic Bt cotton on 9.4 mha—almost 90% of the country’s total cotton area. There is a paucity of information on the effects of intercropping and integrated nitrogen (N)–management practices in transgenic Bt cotton on productivity, nutrient availability, and soil biological properties in the succeeding wheat crop in a cotton–wheat system. A study was made to evaluate and quantify the residual effect of two-tiered intercropping of cotton and groundnut with substitution of 25–50% recommended dose of nitrogen (RDN) of cotton by farmyard manure (FYM) on productivity and soil fertility in a cotton–wheat system at New Delhi during 2006–2008. Wheat following groundnut-intercropped cotton receiving 50% RDN substitution through FYM had significantly 5% greater grain yield than that after sole cotton. Residual soil fertility in terms of organic carbon (C), potassium permanganate (KMnO4)-N, and dehydrogenase activity (14%) showed an improvement under cotton + groundnut–wheat system with substitution of 50% RDN of cotton by FYM. Apparent N balance as well as actual change in KMnO4-N at wheat harvest was negative in most of the treatments, with greater loss (–58.1) noticed under pure stand of the cotton–wheat system with 100% RDN of cotton through urea. The study suggested that inclusion of legume and organic manure in transgenic Bt-cotton–wheat system is a sustainable practice for combating escalating prices of N fertilizers with environmental issues and instability of transgenic hybrids in south Asian countries. 相似文献
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Seyed Abdolreza Kazemeini Reza Moradi Talebbeigi Mohsen Valizade 《Archives of Agronomy and Soil Science》2016,62(3):395-412
Wheat (Triticum aestivum L.) residues and nitrogen (N) management are the major problems in the southern part of Iran where irrigated wheat–cotton (Gossypium hirsutum L.)–wheat rotation is a common practice. A 2-year (2009–2011) field experiment was conducted as a split plot design with four replications at a cotton field (Darab), Fars Province, Iran, to determine the influence of different rates of wheat residue (0%, 25%, 50%, and 75%) incorporation and N rates (150, 200, 300, and 400 kg ha?1) on weed suppression, yield, and yield components of cotton. Results showed that a higher residue incorporation and a lower N rate improved weed suppression in both years. For treatments receiving 150 kg N ha?1 and 75% of wheat residues (2250 kg ha?1), weed biomass and density were significantly lower compared to treatments receiving 400 kg N ha?1. The highest cotton lint yield (about 2400–2700 kg ha?1) was obtained by 300 kg N ha?1 in the absence of residue application, in both years. Incorporation of 25% of wheat residue (750 kg ha?1) and application of 300 kg N ha?1 are recommended to guarantee an optimum level of cotton lint yield and weed suppression in a wheat–cotton–wheat rotation in this region. 相似文献
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Wheat (Triticum aestivum L.) yield and quality is influenced by management of the previous crop but is highly dependent on current year management. The objective of this study was to evaluate the response of winter wheat seeded in two tillage systems [conventional tillage (CT) and no-till (NT)] to four N rates applied to a previous cotton (Gossypium hirsutum L.) crop (0, 67, 134, and 202 kg ha−1). The experiment with wheat was conducted on a Dothan sandy loam (fine, loamy siliceous, thermic Plinthic Kandiudults) at the University of Florida North Florida Research and Education Center near Quincy, FL from 1995 to 1997. For most plant characteristics, there was a tillage x N x year interaction. Greater plant emergence (79.4 vs. 65.3%) and grain N (23.5 vs. 21.5 g kg−1), and lower grain moisture (139 vs. 142 g kg−1) were obtained under NT than CT, respectively, in one out of two years. Nitrogen applied to a previous cotton crop increased wheat grain yields, plant height and seed number under NT in 1995–1996 and CT in 1996–1997, head density under NT in both years, harvest index under CT in 1996–1997, and grain N concentration in 1995–1996 and 1996–1997 due to residual plant and soil N. With every 1 kg N applied to a previous cotton crop, wheat grain yields increased by 5.38 kg ha−1 under NT, whereas grain yield under CT was not influenced by N application to cotton in 1995–1996. In 1996–1997, grain yields increased by 4.96 and 4.23 kg ha−1 for wheat grown in NT and CT, respectively. Generally, wheat seeded in NT following cotton did not decrease stand or yields compared to CT and wheat grain yields and grain N content increased with N fertilization of the previous crop. However, we would have to apply about 134 kg N ha−1 to a previous cotton crop to maximize wheat production under NT and CT. 相似文献
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E. Rafique M. Mahmood-ul-Hassan A. Rashid M. F. Chaudhary 《Journal of plant nutrition》2013,36(4):591-616
A five-year cotton–wheat rotation field experiment was conducted on two alkaline-calcareous soils, i.e., Awagat (coarse loamy) and Shahpur (fine silty), to investigate the impact of integrated nutrient and crop residue management on soil and crop productivity. Apparent nitrogen (N) balances were developed. Minimum five-year mean yield (Mg ha?1), obtained with Farmers’ Fertilizer Use (FFU) treatment was: cotton – Awagat, 2.19; Shahpur, 2.45; wheat – Awagat, 3.03; Shahpur, 3.94. With Balance Nutrient Management (BNM), yields increased (P ≤ 0.05) for cotton, 24% in Awagat and 18% in Shahpur soil; and wheat, 37% in Awagat and 24% in Shahpur soil. Maximum crop yields were obtained with Integrated Nutrient Management (INM), i.e., 3–5% higher than with BNM. Crop residue recycling increased the yields further, cotton by 2?7% and wheat by 2–10%. All nutrient management treatments, except for FFU without crop residue recycling, resulted in positive apparent N balances. INM improved SOM and NO3-N, contents. 相似文献
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Elcio L. Balota Arnaldo Colozzi-Filho Diva S. Andrade Richard P. Dick 《Biology and Fertility of Soils》2003,38(1):15-20
A long-term study on the effect of different crop rotations [soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W] and tillage regimes [no-tillage (NT) or conventional tillage (CT)] on microbial biomass and other soil properties is reported. The experiment was established in 1976 in southern Brazil as a split-plot experimental design in three replications. Soil samples were taken in 1997 and 1998 at 0- to 5-, 5- to 10- and 10- to 20-cm depths and evaluated for microbial biomass C, N, P and S by direct extraction methods. The NT system showed increases of 103%, 54%, 36%, and 44% for microbial biomass C, N, P, and Cmic:Corg percentage, respectively at the 0- to 5-cm depth. NT systems also increased the C to N:S:P ratios. These results provide evidence that tillage or crop rotation affect microbial immobilization of soil nutrients. The larger amount of C immobilized in microbial biomass suggests that soil organic matter under NT systems provides higher levels of more labile C than CT systems. 相似文献