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1.
矿质养分输入对森林生物固氮的影响   总被引:1,自引:0,他引:1  
郑棉海  陈浩  朱晓敏  毛庆功  莫江明 《生态学报》2015,35(24):7941-7954
生物固氮是森林生态系统重要的氮素来源,并且在全球氮循环中占有重要的地位。近代以来,因人类活动加剧而导致氮沉降的增加以及其它矿质养分元素(如磷、钼、铁等)输入的改变已成为影响森林生态系统生物固氮的重要因素之一,并引起了学术界的普遍关注。综述了国内外关于森林生物固氮对矿质养分输入的响应及机理。主要内容包括:(1)森林生物固氮的概念及主要的测定方法;(2)矿质养分输入对森林生物固氮的影响。整体上讲,氮素输入抑制了森林生物固氮,磷和其他营养元素输入则表现为促进作用。氮和磷、磷和微量元素同时添加均提高了森林的固氮量;(3)矿质养分改变森林生物固氮的机理。包括生物作用机制(如改变地表层固氮菌的数量或群落丰度、改变结瘤植物的根瘤生物量和附生植物的丰度或盖度)和环境作用机制(如引起土壤酸化、改变碳源物质的含量);(4)探讨了矿质养分输入对森林生物固氮影响研究中所存在的问题,并对未来该领域的研究提出建议。  相似文献   

2.
植物的生长和发育离不开养分,其中所需的矿质营养主要来自根系的吸收。根系在供应植株地上部养分的同时,它还受到地上部养分需求的调节。因此植物根系和地上部之间保持着密切的联系,这种联系就是通过植物体内的养分循环来实现。植物体内的养分循环是指根系吸收的矿质营养,经木质部运输到地上部,其中一部分养分又经韧皮部返回根系的过程,即矿质营养经历了一个完整的循环过程:根系→木质部→地上部→韧皮部→根系。上述由地上部返回到根中的养分不能被根系完全利用,其中一部分又可经木质部再次运到地上部分,这一过程称为养分的再循环。根据矿…  相似文献   

3.
植物对养分吸收的方式分为:主动吸收、被动吸收和胞饮吸收三种。在植物体内,几乎可发现所有存在于土壤中的各种元素,这充分说明了被动吸收对植物矿质养分吸收的重要性。在矿质养分被动吸收过程中,溶于水中的离子对,以水为载体进入植物体内。土壤化学称这股荷电的离子为离子流;对植物而言,进入植物体内的这股离子流即营养流。荷电的离子流源源不断地通过根系,进入植物体内,并定向地运往地上部,这个过程表现为可检测出的植物生物电流。由此可见,植物矿质养分的被动吸收,不仅受到蒸腾作用、光合作用等耗水代谢的影响,而且还受到电磁场、太阳辐射能和月球引力作用——潮汐等大地物理诸因子的影响。因此,研究植物体生物电的变化规律,可在一定程度上较综合地反映植物对矿质养分的总体吸收情况。为此,本试验  相似文献   

4.
杀灭土壤中线虫对小麦生长和吸收N,P的影响   总被引:10,自引:2,他引:8  
盆栽条件下研究了施用杀线剂(克线磷,67mg·kg-1干土)和干热(105℃,2h)两种杀线措施对小麦生长和N、P养分吸收的影响.杀线剂对土壤中线虫的平均杀灭率约为80%,干热处理的杀灭率为100%.在杀线剂处理中,苗期至抽穗期小麦生物量、拔节期至成熟期植株含N量、全生育期植株吸N量以及抽穗和成熟期吸P量均显著低于对照.土壤干热处理后抽穗和成熟期小麦的生物量、含N量及N、P吸收量也比对照显著降低.两种杀线处理植株地上部生物量和N、P吸收量与相应处理全株变化趋势基本一致.但杀灭线虫对植株含P量影响较小.分析杀线虫后小麦生长和养分吸收受抑主要与土壤有机氮的矿化作用减弱、微生物活动产生的植物生长促进物质降低有关  相似文献   

5.
盆栽条件下研究了施用杀线剂(克线磷,67mg·kg-1干土)和干热(105℃,2h)两种杀线措施对小麦生长和N、P养分吸收的影响。杀线剂对土壤中线虫的平均杀灭率约为80%, 干热处理的杀灭率为100%. 在杀线剂处理中,苗期至抽穗期小麦生物量、拔节期至成熟期植株含N量、全生育期植株吸N量以及抽穗和成熟期吸P量均显着低于对照。土壤干热处理后抽穗和成熟期小麦的生物量、含N量及N、P吸收量也比对照显着降低。两种杀线处理植株地上部生物量和N、P吸收量与相应处理全株变化趋势基本一致。但杀灭线虫对植株含P量影响较小。分析杀线虫后小麦生长和养分吸收受抑主要与土壤有机氮的矿化作用减弱、微生物活动产生的植物生长促进物质降低有关  相似文献   

6.
植物化感物质及化感潜力与土壤养分的相互影响   总被引:10,自引:0,他引:10  
植物化感作用与许多生态因子有关.土壤养分缺乏,影响着许多植物化感物质的产生,从而影响植物的化感潜力;反过来,植物化感物质也通过络合、吸附、酸溶解、竞争、抑制等方式影响土壤的养分形态和水平.本文总结了植物化感物质及化感潜力与土壤养分的相互影响,并提出了今后该领域值得进一步研究的问题.包括以下几方面:加强植物化感研究与土壤 植物营养学研究的结合,以更深入地阐明植物化感物质、化感作用与土壤养分变化的关系;加强植物化感研究与生态系统养分循环研究的结合,以类似自然(nature-like)的方式模拟自然界植物所受的养分干,使养分干扰的化感研究结果更加逼真、可靠;加强对养分过量及受污染时植物化感作用的研究,为揭示农业和林业生产中植物的相互作用机制和生物量变化机制提供新的思路,为生态保护提供科学依据.  相似文献   

7.
矿质元素在植物体内的运输和分配一株植物要想正常生存,就必须靠根系从土壤中不断吸收生活所必需的水分和矿质营养;靠叶片从周围环境中吸收二氧化碳和光能进行光合作用制造有机物质。这还不够,这些被吸收的和在体内制造的物质还必须进行交换、互通有无,才能满足植物作为一个整体来进行生命活动。那么矿质和有机物质是以什么方式,通过什么途径,用什么样的速度进行交换和运输的呢?运输的动力又是什么呢?这些问题有的已经弄清,有的至今还未解决,现就有关问题简述如下: 矿质元素在植物体内的运输 1.运输方式无机离子通过根系吸收后,  相似文献   

8.
通过田间试验研究了种植方式(玉米单作、大豆单作、玉米-大豆套作)和施氮水平(0、180、240 N kg·hm-2)对玉米和大豆产量、养分吸收及氮肥利用的影响.结果表明:与单作相比,玉米-大豆套作体系中玉米籽粒产量、地上部植株N、P、K吸收量及收获指数略有降低,而大豆籽粒产量、地上部植株N、P、K吸收量及收获指数显著提高.玉米-大豆套作系统的套作优势随施氮量的增加而降低,与当地农民常规施氮量(240 kg·hm-2)相比,减量施氮(180kg·hm-2)处理下玉米和大豆产量、经济系数,以及N、P、K吸收量和收获指数、氮肥农学利用率、氮肥吸收利用率显著提高,土壤氮贡献率降低;与不施氮相比,减量施氮降低了玉米带土壤的全N、全P含量,提高了大豆带土壤的全N、全P、全K含量和玉米带土壤的全K含量.减量施氮水平下,玉米-大豆套作系统的周年籽粒总产量、地上部植株N、P、K总吸收量均高于玉米和大豆单作,土地当量比(LER)达2.28;玉米-大豆套作系统的氮肥吸收利用率比玉米单作高20.2%,比大豆单作低30.5%,土壤氮贡献率比玉米和大豆单作分别低20.0%和8.8%.玉米-大豆套作减量一体化施肥有利于提高系统周年作物产量和氮肥利用率.  相似文献   

9.
《环境昆虫学报》2013,35(1):61-66
实验测定了马尾松Pinus massoniana、黑松Pinus thunbergii在松材线虫Bursaphelenchus xylophilus自然侵染状态下针叶内还原糖及矿质营养元素的变化趋势。结果表明,两种松树随病程发展针叶内还原糖及N元素含量均逐渐降低;其余矿质元素含量变化不一。表明由于松材线虫的侵入,破坏了植物的组织结构,影响了寄主的新陈代谢和物质循环,继而影响到对各种元素的吸收、转移及利用。  相似文献   

10.
张科  田长彦  李春俭 《生态学报》2012,32(10):3069-3076
选用古尔班通古特沙漠南缘荒漠-绿洲交错带常见的一年生盐生植物盐角草、刺毛碱蓬、叉毛蓬、猪毛菜和碱地肤为材料,比较了它们在原状盐土和沙土中的生长及体内矿质元素组成的差异。结果表明:① 原状盐土0—100 cm各土层的pH值低于沙土,但电导率和含水量明显高于沙土;② 原状盐土中生长的植物干重是沙土中生长植物干重的7—118倍,后者的根冠比是前者的2—6倍。③ 体现肉质化程度的地上部含水率为52%—81%,中低耐盐植物含水率在两种土壤中差异显著,强耐盐植物差异不显著;④ 5种一年生盐生植物地上部氮浓度为11—34 g/kg,在有效氮含量高的盐土上植物氮浓度也高;磷浓度为1—4 g/kg,在有效磷高的盐土上植物磷浓度也较高(盐角草除外);但沙土中的植物地上部钾浓度明显高于盐土中植株的地上部钾浓度,这与两种土壤在0—60 cm土层中的钾浓度差异相反;⑤ 尽管原状盐土0—100 cm土层中的水溶性钙、镁、钠、氯、硫浓度显著高于沙土,盐土与沙土中生长的植物地上部钠、水溶性氯和硫的浓度比值远远低于土壤中的相应元素浓度的比值,甚至盐土中的植株钙、镁浓度等于或显著低于沙土中生长的植物。表明盐土不仅影响一年生盐生植物的生长,也显著影响这些植物对矿质元素的吸收和累积。一年生盐生植物能够选择性吸收不同生境中的矿质元素。本研究期望为进一步深入研究盐生植物耐盐的适应机制提供依据,也可为植物修复盐碱土的品种选择提供参考。  相似文献   

11.
连作对大豆根部土壤微生物的影响研究   总被引:46,自引:0,他引:46  
研究了正茬与连作大豆根际及非根际土壤微生物区系的变化。结果表明,细菌总数占绝对优势,连作低于正茬。放线菌数量总体变化幅度不大,真菌数量有显著变化,连作明显高于正茬。连作使土壤pH、含水率和微生物主要生理类群数量明显下降,土壤肥力降低。无论细菌、放线菌和真菌,正茬及连作大豆根际微生物数量明显高于非根际。  相似文献   

12.
Aims: Glyphosate‐resistant (GR) soybean production increases each year because of the efficacy of glyphosate for weed management. A new or ‘second’ generation of GR soybean (GR2) is now commercially available for farmers that is being promoted as higher yielding relative to the previous, ‘first generation’ (GR1) cultivars. Recent reports show that glyphosate affects the biology and ecology of rhizosphere micro‐organisms in GR soybean that affect yield. The objective of this research was to evaluate the microbiological interactions in the rhizospheres of GR2 and GR1 soybean and the performance of the cultivars with different rates of glyphosate applied at different growth stages. Methods and Results: A greenhouse study was conducted using GR1 and GR2 soybean cultivars grown in a silt loam soil. Glyphosate was applied at V2, V4 and V6 growth stages at three rates. Plants harvested at R1 growth stage had high root colonization by Fusarium spp.; reduced rhizosphere fluorescent pseudomonads, Mn‐reducing bacteria, and indoleacetic acid–producing rhizobacteria; and reduced shoot and root biomass. Conclusions: Glyphosate applied to GR soybean, regardless of cultivar, negatively impacts the complex interactions of microbial groups, biochemical activity and root growth that can have subsequent detrimental effects on plant growth and productivity. Significance and Impact of the Study: The information presented here will be crucial in developing strategies to overcome the potential detrimental effects of glyphosate in GR cropping systems.  相似文献   

13.
  1. Cover crops offer environmental and agricultural benefits, but adoption remains low. Soybean growers have indicated that the adoption of rye as a winter cover crop would increase, if it was shown to offer suppression of a key soybean pest, the soybean aphid Aphis glycines.
  2. We performed an on‐farm evaluation of two cropping systems utilized in organic production and reduced‐herbicide input production. One system includes a rye cover crop, whereas the other does not.
  3. At six and five location‐years in Minnesota, A. glycines and predator populations, respectively, were measured and compared between the systems with and without rye.
  4. The system with the rye cover crop significantly suppressed A. glycines populations on soybean at five of six location‐years. Predators appeared to respond more to prey abundance than to plant diversity. An exposure analysis examining biological control potential revealed no differences between soybean with and without rye at any location‐year.
  5. Insect control can be added to the multiple benefits of rye winter cover crops.
  相似文献   

14.
Triticale cv. Beagle 82, cotton cv. McNair 235, and soybean cv. Twiggs were arranged in three cropping sequences to determine the effects of fenamiphos and cropping sequence on nematode population densities and crop yields under conservation tillage for 4 years. The cropping sequences were triticale (T)-cotton (C)-T-C, T-soybean (S)-T-S, and T-C-T-S. Numbers of Meloidogyne incognita second-stage juveniles declined on trificale but increased on cotton and soybean each year. Root-gall indices of cotton and soybean ranged from 1.00 to 1.08 (1 to 5 scale: 1 = 0%, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled) each year and were not affected by fenamiphos treatment or cropping sequence. Numbers of Pratylenchus brachyurus were maintained on trificale and generally increased more on soybean than on cotton. Population densities of Helicotylenchus dihystera were near or below detection levels in all plots during the first year and increased thereafter in untreated plots in the T-C-T-C and T-S-T-S sequences. Generally, yields of triticale in all cropping sequences declined over the years. Yields of cotton and soybean were not affected by fenamiphos at 6.7 kg a.i./ha. Cotton and soybean were grown successfully with little or no suppression in yields caused by nematodes in conservation tillage following triticale harvested for grain.  相似文献   

15.
玉米株型和幅宽对套作大豆初花期形态建成及产量的影响   总被引:20,自引:0,他引:20  
在“麦/玉/豆”套作模式下研究了不同幅宽和玉米株型对大豆生长前期形态建成和产量的影响.结果表明:不同株型玉米下大豆生长带的温度、湿度和透光率是导致大豆茎叶形态和组织解剖结构出现差异的直接原因.较大幅宽和紧凑型玉米下大豆的植株较矮,主茎较粗、干物质积累量较大,叶面积指数和比叶质量较高,产量较高;而较小幅宽和松散型玉米下大豆的茎叶生长不良,株高增长过快,主茎柔弱,容易倒伏,产量较低.在1.17 m/0.83 m(大豆/玉米)幅宽下对不同株型玉米影响下的大豆初花期茎、叶组织切片观察发现,随着荫蔽程度的加重,大豆的叶片变薄,表皮细胞体积变大,角质层变薄,栅栏组织和海绵组织分化不明显,细胞间隙增大;茎的表皮和次生木质部也变薄,薄壁细胞排列疏松,导管分化较迟,韧皮纤维不发达.套作模式下保证全年高产、高效的田间最优配置为:与紧凑型玉米套作,大豆幅宽1.17 m,玉米幅宽0.83 m.  相似文献   

16.
以黑龙江省大豆重茬 5年与正茬土壤和根系为主要研究对象 ,采用高效液相色谱法 ,研究土壤和根系浸提液中的酚酸物质的含量及其生物学效应 .结果表明 ,重茬土壤中对羟基苯甲酸和香草酸的含量 (1mol·L-1NaOH提取 )大于正茬土壤 ,且差异达到极显著水平 ,香草醛含量差异不显著 ;重茬大豆根系水提液中对羟基苯甲酸、香草酸、阿魏酸、香草醛、香豆素含量均高于正茬 .大豆连作条件下土壤多酚氧化酶活性高于正茬土壤 .重茬大豆根系水提液及在水培条件下外加对羟基苯甲酸对大豆幼苗生长发育有一定的抑制作用 ;酚酸物质加入土壤 1周后 ,对羟基苯甲酸、香草酸、香草醛、阿魏酸、苯甲酸、香豆素残留率分别为 10 .4%、15 .3 %、4.1%、2 .3 %、5 .0 %、17.5 % ;且外加酚酸浓度与土壤中真菌数量呈极显著指数相关 .  相似文献   

17.
大豆地上部水浸液的化感作用及化感物质的鉴定   总被引:37,自引:2,他引:35  
韩丽梅  沈其荣  鞠会艳  阎石  阎飞 《生态学报》2002,22(9):1425-1432
研究了重迎茬大豆花荚期植株地上部水浸液及其提取物对大豆种子萌发及幼苗生长的化感作用 ,并鉴定了有明显化感作用组分的物质。结果表明 :与对照组比 ,0 .1 0 g DW/ ml重茬大豆水浸液显著地抑制了大豆胚根生长 ;3 .75× 1 0 - 2g DW/ ml、7.5 0× 1 0 - 2 g DW/ ml正茬、重茬、迎茬大豆水浸液对砂培大豆苗的生长有显著的化感抑制作用 ;重茬、正茬大豆水浸液乙酸乙酯提取的酸性组分、XAD-4树脂提取组分 ,在 0 .6~ 1 .2 g DW/ ml浓度下 ,对大豆种子萌发初期的萌发率及萌发过程中的胚根生长亦表现出显著的化感抑制作用 ;重茬水浸液乙酸乙酯提取的中性、碱性组分在 1 .2 g DW/ ml浓度下 ,对大豆胚根生长有显著抑制作用。上述各组分化感作用大小随组分浓度增加而增加。在相同浓度处理下水浸液及其提取物的化感抑制作用有重茬大于正茬的趋势 ,统计检验差异均不显著。 GC-MS鉴定结果显示 ,正茬、重茬乙酸乙酯酸性组分、XAD-4树脂提取组分中的有机化合物主要是 :丁二酸、苯甲酸、邻羟基苯甲酸、4-羟基苯甲酸、对羟基肉桂酸、2 -甲基苯酚、2 -甲氧基 -4-乙烯基苯酚、间苯三酚、2 -甲基苯甲醛、3 -甲基苯甲醛、5 ,6,7,7a-四氢 -4,4,7a-三甲基 -2 (4 H) -苯并呋喃酮、2 ,4-戊二烯腈等。  相似文献   

18.
Phytophagous stink bugs are major soybean pests, and knowledge of spatial distribution models of the pest in the crop is fundamental to establishing an appropriate sequential sampling plan, and thus, allowing the correct utilization of control strategies. This work aimed to study the spatial distribution of phytophagous stink bugs in soybean grown in different cropping systems and determine a sequential sampling plan. The experiment was conducted in Maracaju, MS, Brazil, during the agricultural year of 2012/2013. Soybean cultivars BRS 284 and SYN 1163 RR were placed in an experimental area comprising six fields (two soybean cultivars × three cropping systems). Sampling was performed weekly, using a beat cloth per plot and counting the number of stink bugs found, virtually throughout the soybean reproductive period. Concerning the statistical analyses, we used the dispersion indexes (variance‐to‐mean ratio, Morisita's index, exponent k of the negative binomial and Green's coefficient) and probabilistic methods of frequency adjustment (negative binomial and Poisson). Adult and nymph phytophagous stink bugs showed aggregate disposition in the field regardless of the cropping system, and their numbers were adjusted to the negative binomial probability distribution. There was no difference in the behaviour of adult and nymphs considering the tested cultivars. We elaborated a practical sequential sampling plan for phytophagous stink bug complexes, considering crops intended for the production of grains and seeds.  相似文献   

19.
An 11-year field study was initiated in 1979 to monitor population development of Heterodera glycines. Fifty cysts of a race 5 population were introduced into plots in a field with no history of soybean production and that had been in sod for 20 years. Soybean cultivars either susceptible or resistant to H. glycines were grown either in monoculture or rotated with maize in a 2-year rotation. During the first 5 years, resistant cultivars with the Peking source of resistance were planted. After year 5, monocuhure of Peking resistance resulted in 18 cysts/250 cm³ of soil, whereas populations resulting from the continuous cropping of susceptible soybean resulted in 45 cysts/250 cm³. Some plots in all treatments, including control plots, were contaminated at the end of year 5. Crop rotation delayed population development of H. glycines. During years 6 through 11 cv. Fayette (PI88.788 source of resistance) was planted. In year 6 numbers of cysts declined to 1/250 cm³ of soil in the treatment consisting of monocultured Fayette. At the end of year 10, cysts were below the detection level in all treatments in which Fayette was planted. Yield of susceptible soybean in monoculture with or without H. glycines infestation was lower beginning in year 6 when compared to yield of soybean grown in rotation and remained lower throughout the duration of the experiment except for 1987 (year 9). Yields of susceptible and resistant soybean were different each year except for drought years in 1980 and 1988. From 1979 to 1982 differences in yield were due to lower yield potential of resistant cultivars. Except for the drought year, yield of cv. Fayette was greater than susceptible Williams 82 during years 6 through 11.  相似文献   

20.
This study evaluated the effects of agroecosystem diversification through no-tillage and strip intercropping on the abundance of natural enemies of soybean (Glycine max Merrill) herbivores. Twenty-four plots (289 m2 each) were arranged in a randomized complete block design for a 3 by 2 factorial experiment. Factors were cropping systems (corn monoculture, soybean monoculture, and strip intercropping of corn and soybean) and tillage systems (no-tillage and conventional tillage). Natural enemies were sampled during 1988, 1989 and 1990 by sweep net, suction net (D-Vac), pitfall traps and quadrat samples. Analyses of variance indicated that of 15 taxa analyzed, most foliage-inhabiting natural enemies were significantly more abundant in intercropping than in monoculture plots, whereas soil-inhabiting natural enemies had higher numbers in no-tillage plots than conventional tillage plots. Therefore, the results support the theory of greater abundance of natural enemies in more complex agroecosystems. Better environmental conditions in diversified treatments was the possible reason for these results. Corn in intercropping plots provided shade, reduced wind speed, alternate food, and possibly higher humidity and lower temperatures for soybean natural enemies. A similar effect was likely cuased by the stubble and weeds, in no-tillage plots.  相似文献   

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