湖北江汉平原农田生态系统钢的循环与平衡

对湖北江汉平原农田生态系统8种种植模式中Cu的输入、输出和平衡进行了分析。结果表明,农田Cu的输出主要是作物收获,其输出量占总输出量的85.9%-95.1%,流失和淋溶输出很少,农田Cu的输入主要是有机肥输入和降雨输入,其次是降尘、作物自然归还和灌溉,而种子种苗和无机肥输入占很少的比例。农田Cu的平衡分析表明,按照当地施肥习惯,菜田和水田Cu盈余较多,而旱地4种种植模式基本平衡。     

鄂南棕红壤农田生态系统B素平衡分析

以湖北省咸宁市贺胜桥镇上孟村农田生态系统为研究对象,分析了当地油／豆－稻、麦／瓜－稻、油／玉米－大豆、小麦－芝麻、大豆－芝麻等５种种植方式的Ｂ素平衡,结果表明,农田Ｂ素的输出主要是径流和淋溶,它们分别占总输出的４８％－５３％和４１％,由产品输的量相对较小,只占总输出的３．４％－１０．１％,当地农田Ｂ素棉入主要有降雨,灌溉,施肥,种子种苗和自然归还。     

麦-稻两熟集约生产土壤养分平衡与调控研究

以兴化市钓鱼乡为例,研究了麦－稻两熟集约生产的土壤有机质、养分的动态平衡以及调控途径。结果表明,在不同的管理模式下,高产农田有机物归还量比一般产量条件下高１４．２２％￣１８．６９％,氮、磷盈余量、钾亏缺量分别为３８０．０￣４３２ｋｇ／ｈｍ＾２、１９．１５￣３２．７８ｋｇ／ｈｍ＾２、９９．１￣１７４．０ｋｇ／ｈｍ＾２,与一般产量条件下比较,氮、磷盈余量提高,而钾的亏缺量相近,提出了改善高产农田土壤肥     

易旱农田生态系统养分循环的研究

对多熟制农田生态系统的养分循环研究表明,小麦后稻-稻(农田Ⅰ)、大麦后稻-豆(农田-Ⅱ)和油菜后稻-稻(农田-Ⅲ)复种制Ca、Mg有盈余。P、K、Fe、Mn均表现亏缺,N素有较大的浪费。N、P、K主要通过肥料输入农田生态系统,而随农产品输出系统外,Ca、Mg主要受水循环控制,作物残留部分中,N的残留量最大,为23—71kg·ha~(-1),Fe的残留率最高,为64—87％。     

施用硫肥对几种作物与牧草产量和硫素含量的影响

为了研究不同作物的需S状况。对我国北方3种主要农作物(小麦、玉米、油菜)和牧草(苜蓿)进行了5个施硫水平(0、5、10、20和40mg·kg^-1)的盆栽试验．结果表明。增施一定量的硫肥可以提高作物生物量和产量．4种作物生物量增加5％～32％．小麦和油菜籽粒产量增加3％～20％．同时。增施硫肥可以使作物体内S素增加,但不同作物含硫量明显不同,油菜含硫量最高(0．479％～1．228％)。玉米含硫量最低(0．043％～0．091％)．同一作物不同部位含硫量不同。但同一作物不同部位含硫量呈显著的线性正相关．如油菜I、油菜Ⅱ和小麦植株与其种子含硫量的相关性都达极显著水平,R2值分别为0．399、0．654和0．547(n=15)．作物生物量、产量与施硫量相关性除苜蓿外．都达显著或极显著水平;作物生物量、产量与作物体内硫素含量除苜蓿外也显著或极显著相关;作物从土壤中吸收的S开始时随土壤的有效硫增加而增加,但达到一定程度时。随着有效硫的增加吸收的S略有下降．     

农田生态系统N、P营养平衡及其肥料效应

９年的农田生态系统Ｎ、Ｐ营养平衡定位试验研究表明,Ｎ、Ｐ肥配合施用,实行秸秆还田,可提高土壤有机质和全Ｎ含量,使土壤速效和迟效Ｐ库容量得到补充．最后几年的Ｐ肥利用率达２１．１—６５．１％,Ｎ肥为４９—７５％．储备性施Ｐ第１年的利用率只有６．５－７．３％,而前３年之和达到２４—２８．５％,９年３个时段平均利用率２７．９—４２．８％,补偿性施Ｐ的１９．５—４２．９％．施Ｐ６５．５ｋｇ·ｈａ－１·ｙｒ－１时,既能满足作物对Ｐ的需求又能补充土壤速效Ｐ库容量．     

长期施肥黄土旱塬农田土壤-微生物-植物系统碳氮磷生态化学计量特征

探讨长期不同施肥制度对农田土壤、植物生态系统的碳(C)、氮(N)、磷(P)含量及其生态化学计量比的影响,可为揭示该系统能量平衡和养分循环,实现农业生态系统元素平衡及可持续发展提供参考意义。以位于黄土高原半干旱地区的长武国家黄土高原农业生态实验站长期施肥试验为研究对象,选取不施肥(CK)、单施氮肥(N)、单施磷肥(P)、施氮磷肥(NP)、单施有机肥(M)、氮肥配施有机肥(NM)、磷肥配施有机肥(PM)、氮磷肥配施有机肥(NPM)8个处理,分析了黄土旱塬典型农田土壤-微生物-植物生态系统中C、N、P含量及其生态化学计量变化规律。研究结果表明:1)长期单施有机肥和化肥配施有机肥处理可显著提高土壤和有机质C、N、P含量。2)氮、磷肥的输入显著降低了土壤和小麦C∶N、N∶P,施P显著降低了有机态C∶P和小麦C∶P;有机肥配施对微生物生物量和小麦C∶N∶P的影响更为明显。3)长期有机肥配施条件下土壤养分和小麦化学计量比存在较强的相关关系。微生物生物量碳与有机C、N、P呈显著正相关,土壤微生物生物量氮与土壤N、P总量呈显著正相关,微生物生物量磷与土壤C、N、P总量含量呈显著负相关;植株碳含量与微生物...     

湖北省主要种植制度农田生态系统钾平衡状况

于2010年和2011年通过10个大田试验,研究了湖北省6种主要种植制度下农田生态系统中钾(K)的输入、输出数量特征和平衡状况。结果表明:6种主要种植制度每年通过施肥、降雨、灌溉和秸秆还田输入农田K量分别为129.8、10.3、14.9和30.1 kg·hm-2,分别占K输入总量66.2%、6.2%、8.8%和18.8%,表明除了施肥外,降雨、灌溉和秸秆还田对K输入也起了重要的作用;通过作物收获和地表径流从农田输出的K量分别为211.2和26.4 kg·hm-2,分别占K输出总量的88.5%和11.5%,其中,通过秸秆输出的K量达到了186.3 kg·hm-2,占作物带走量的89.1%,但秸秆归还的K量只占可以还田的16.2%,这表明农田生态系统中的K大部分被秸秆带走,秸秆还田的潜力巨大;湖北省主要种植制度农田生态系统K整体呈亏缺状态,6种种植制度年平均亏缺量为-52.4 kg·hm-2。因此,增加K肥施用量,重视降雨和灌溉K养分的输入,推进秸秆还田,是改善全省农田生态系统K平衡的有效措施。     

华北太行山前平原农田生态系统中氮、磷、钾循环与平衡研究

以栾城县为例,分析了华北太行山前平原农田生态系统N、P、K三要素养分循环与平衡特征及其变化趋势,评价了农田养分平衡状况,提出了合理施肥对策。结果表明,1985～2000年栾城县农田养分平衡中,N素经历了由轻微赤字向盈余的转变过程,由1985年的1．4％赤字转变到2000年盈余48．6％;K由极度亏缺(82％赤字),逐渐向平衡发展,到2000年已有4．6％的轻微盈余,但仍有大量田块是赤字平衡;P则始终有大量盈余。目前农田养分收支存在一定程度的N、P投入过量,K投入不足的问题,以土壤肥力状况和作物种植结构而论,栾城县应采取“稳氮、控磷、增钾”的施肥对策。避免过多的盈余化肥氮进入环境,同时应继续推广秸秆还田技术,提高养分循环再利用效率。     

陕西省有机肥料施用状况分析评价

根据陕西省土壤肥料工作站14年农户肥料施用调查结果,对陕西有机肥施用的历史和现状进行了剖析,有机肥在农田总养分(N+P2O5+K2O)投入中的比重逐年减少,2000年只占46．9％。比1986年下降了近23个百分点,在农田钾素主要依靠有机肥供应的情况下,有机肥投入的减少造成土壤基础肥力逐年下降,有些地区出现钾素营养不足现象,在投肥总量上尽管粮食作物依然为主体,但单位面积投肥量果树、蔬菜则高于粮食作物,特别是从20世纪90年代中期开始一些地区在苹果上的投肥量明显增加,占投肥总量的50％左右。此外,分析了有机肥投入减少的原因,并提出商品有机肥将是今后提高有机肥投入的有效途径。     

Boron-deficiency dieback in pines

Summary and Conclusions Leaf analyses have indicated that the dieback investigated was due to boron deficiency and this has been proved by field experiments. Incidence of boron deficiency is tentatively related to the weathered condition of the soils on which it occurs and a climatic regime which may be alternately too wet and too dry for optimum availability of soil boron. The best means of correcting the deficiency appears to be the application of a small amount of borax — 15 pounds per acre — to the soil towards the end of the rainy season.     

植物对硼的吸收、转运及其遗传调控(综述)

硼是植物生长发育必需的一种微量营养元素,缺硼和硼毒害是国内外农业生产中普遍存在的问题,不仅影响产量,而且还会降低品质。近年来,植物的硼吸收和转运机制研究取得较大进展,从而为基因工程改良植物的缺硼和硼毒害奠定了重要基础。本文就植物对硼的吸收和转运机制以及植物对缺硼和硼毒害耐性的遗传调控研究概况进行综述。     

Boron deficiency increases putrescine levels in tobacco plants

Polyamine concentrations were determined in leaves and roots of tobacco plants (Nicotiana tabacum L.) subjected to a short-term boron deficiency. A decrease in the growth of shoots and, especially, roots was found under this mineral deficiency. Boron deficiency did not lead to a significant decrease in leaf or root ion concentrations when compared to control treatment; however, as expected, leaf boron concentration was lower in boron-deficient plants in comparison to the control. In leaves, the levels of free putrescine and spermidine were similar in both treatments. In roots, a short-term boron deficiency caused an increase in free putrescine. Moreover, boron-deficient plants had higher conjugated polyamine concentration than boron-sufficient plants, which was especially evident for conjugated putrescine in leaves. A possible link between boron and polyamine levels is proposed and discussed.     

Effect of Boron Deficiency on Photosynthesis and Reductant Sources and Their Relationship with Nitrogenase Activity in Anabaena PCC 7119

Nitrogenase activity of Anabaena PCC 7119 is inhibited under conditions of boron deficiency. To elucidate the mechanisms of this inhibition, this study examined how the deficiency of boron affected photosynthesis, photosynthetic pigments, the enzymes of the oxidative pentose phosphate pathway, and respiration of Anabaena PCC 7119 cultures. After 24 to 48 hours of boron deficiency, reductions in photosynthetic O₂ evolution and in CO₂ fixation were observed. At the same time, the activities of oxidative pentose phosphate pathway enzymes and respiration increased significantly with boron deficiency. No change was observed in these processes when assays were performed after 4 to 6 hours of deficiency, a time at which nitrogenase activity was severely inhibited. These results suggest that the requirement for boron in N₂ fixation is independent of its effects on photosynthesis and reductant supply.     

氮磷钾、硼水平对不同基因型油菜硼吸收及某些生物学性状的影响

采用温室土培试验,研究了不同氮磷钾复合型（NPK肥）施用水平下,油菜对B的吸收及其耐缺B机理以及缺B对某些生物学性状的影响,结果表明,缺B时,随NPK肥施用量的增加,油菜植株缺B症状加重,苗期叶面积及其生长速率减小,叶绿素含量增加,硝酸还原酶活性下降,成熟期单株有效分枝,有效角果数减少,籽粒产量降低,可以认为,油菜大苗期最新展开叶（YOL）与最新成熟叶（YML）的B浓度比值可作为不同基因型油菜植株体内B移动性大小的判氟指标,B移动性及B利用率的大小是不同基因型油菜耐缺B的重要营养机理之一。     

A Comparison of the Boron Requirements of Intact Tomato Plants and Excised Tomato Roots grown in Sterile Culture

A method is described by which boron deficiency in excised tomatoroots was obtained. Lack of boron caused complete inhibitionof growth after three days in sterile culture. The boron concentrationsupporting 50 per cent of the maximum root-growth response issimilar to that giving a 50 per cent growth response with intactplants of the same variety. These results are discussed withregard to the function of boron in plant growth.     

The Role of Boron in Plant Growth: IV. INTERRELATIONSHIPS BETWEEN BORON AND INDOL-3YL-ACETIC ACID IN THE METABOLISM OF BEAN RADICLES

The hypothesis that boron deficiency is equivalent to a stateof IAA toxicity was explored. Bioassays showed that extractsof substances similar to IAA taken from boron-deficient rootswere significantly more inhibitory to the growth of bean-rootsegments than those from normal roots. Supplied IAA and borondeficiency together restricted root growth to a greater extentthan either deficiency or IAA treatment separately. Roots werefound to recover more quickly from the inhibitory effects ofsupplied IAA if boron was present at high (0.5 ppm) rather thanlow (0.01 ppm) concentrations. Experiments with ¹⁴C-labelled IAA showed that deficient rootsabsorbed ¹⁴C more slowly than boron-fed roots and there wasalso a lower rate of decarboxylation in the deficient tissue.Consideration of the published evidence showed that many ofthe effects of boron deficiency could follow from an upset inIAA metabolism. It is suggested that boron-deficient tissuesuffers from excess auxin either because the element is necessaryfor some growth process, such as cell wall formation or nucleicacid synthesis, which, when impaired, results in the accumulationof auxin, or because the IAA-oxidation system is affected byphenolic inhibitors which boron normally inactivates by complexformation.     

微量元素硼对林木生长的影响

硼 (Ｂ)是植物生长过程中不可缺少的微量元素之一 ,它对植物中糖的运输、核酸与蛋白质的合成、光合作用、花粉萌发、受精和结实等均有作用。农业上对Ｂ的研究和应用较多。早在 192 3年英国人Ｗａｒｉｎｇｔｏｎ[4 5] 就报道Ｂ对植物生长发育的重要性。此后 ,曾多人对此研究进行了较为详细的综述[33,34 ,36 ,4 3] 。我国低Ｂ和缺Ｂ土壤分布很广 ,主要分布在东部 ,尤其是东南部[9] 。在这些地区报道甘蓝型油菜、棉花和一些果树出现缺Ｂ症状 ,如甘蓝型油菜“花而不实”和棉花“蕾而无花”等。黑龙江省曾发现小麦、大麦、玉米、大豆、甜菜等严重…     

Requirement of ginkgo pollen-derived tissue cultures for boron and effects of boron deficiency

Ginkgo biloba L. pollen-derived tissue, which is made up of small, friable masses of homogeneous parenchymatous cells, was shown to require boron in the culture medium. If no boron is supplied, growth soon stops. Growth responses to additions of boron were observed up to an optimum level of 0.1 mg of boron per liter.

Histological examination and chemical analyses showed 2 general effects of boron deficiency: (1) a reduced rate of cell division, with no significant effect on cell size, and (2) some alteration in composition of the cell walls. With the exception of a reduction in fructose, the concentration of soluble and of readily hydrolyzable carbohydrates, and the concentration of protein in the tissue, were not affected by boron deficiency.