不同磷水平下小麦蚕豆间作对根际有效磷及磷吸收的影响

【目的】探明不同磷水平下小麦–蚕豆间作对根际有效磷含量及作物磷吸收量的影响,提高磷肥利用率。【方法】2015—2016和2016—2017两季田间试验在云南农业大学试验基地耕作红壤上进行,供试小麦品种为云麦-52,蚕豆品种为玉溪大粒豆。设施P2O5 0 (P0)、45 (P45)和90 kg/hm^2 (P90)三个水平,和单作(M,包括小麦单作MW和蚕豆单作MF)和间作(I)两种种植模式。每季在小麦分蘖期、拔节期、抽穗期、灌浆期和成熟期,蚕豆分枝期、开花期、结荚期、籽粒膨大期、收获期采取根际土样测定有效磷含量。在小麦蚕豆收获期测定单、间作小麦、蚕豆产量,并测定作物地上部磷含量。计算土地当量比(LER)来衡量间作优势,并用磷肥农学利用率来反映磷肥的吸收效率。【结果】与单作相比,在P0、P45、P90水平下,2016年间作种植显著提高了小麦籽粒产量12.5%、21.7%和17.3%,2017年间作蚕豆产量较单作分别降低了16.8%、11.7%和8.2%。三个磷水平下,小麦–蚕豆间作具有产量优势,土地当量比(LER)为0.95~1.18。与常规施磷水平(P90)下的单作相比,小麦–蚕豆间作条件下,磷肥减施1/2 (P45)并未降低小麦和蚕豆产量。间作种植对小麦根际有效磷含量无显著影响(除2016年成熟期外),但2017年,在蚕豆分枝期、开花期、结荚期,间作则分别降低蚕豆根际有效磷含量20.8%、44.5%和18%。与P90单作相比,间作P45处理几乎不会降低小麦、蚕豆根际有效磷含量。小麦、蚕豆磷吸收量主要受磷水平的调控,种植模式对小麦和蚕豆磷的吸收量及磷肥农学利用率均没有影响。【结论】在本试验条件下,小麦–蚕豆间作提高了小麦籽粒产量,降低了蚕豆产量;间作种植主要是改变了蚕豆生育前期根际有效磷含量,但对作物的磷吸收量没有影响。小麦–蚕豆间作具有减施磷肥、维持作物产量和根际土壤有效磷的潜力。     

不同抗性小麦品种与蚕豆间作对小麦根际速效养分含量的影响

通过田间试验研究了3个对白粉病抗性不同的小麦品种93-124(低抗)、云麦-47(高抗)和云麦-42(中抗)分别与蚕豆间作对小麦不同生育期根际速效氮、磷、钾养分的影响差异。结果表明,在单作条件下,不同抗性小麦品种间根际速效氮含量和根际速效钾含量在各生育期均无显著差异,根际有效磷含量在分蘖、拔节、抽穗期无显著差异,灌浆期93-124根际有效磷含量显著高于云麦-42。小麦蚕豆间作显著提高了分蘖、拔节和抽穗期小麦根际土壤速效氮、磷、钾含量,降低了成熟期根际速效氮、有效磷含量。在分蘖至抽穗期,与单作相比,93-124、云麦-47和云麦-42的根际碱解氮含量分别提高了23.16%~46.90%、23.74%~31.78%和11.23%~22.44%间作93-124的根际有效磷含量提高了35.26%~59.63%;间作云麦-47根际速效钾提高了10.87%~57.59%。间作提高根际速效氮、磷养分的效应以93-124最高,间作提高根际速效钾的效应以云麦-47最高。小麦蚕豆间作具有显著的产量优势,93-124、云麦-47和云麦-42的LER(土地当量比)分别为1.01,1.20和1.14。     

小麦蚕豆间作改善蚕豆根际微生物区系与减轻蚕豆枯萎病的作用

本文用盆栽试验的方法和应用稀释平板计数法、实时荧光定量PCR法及BIOLOG技术,通过比较单作和单作蚕豆根际土壤可培养的细菌、真菌、放线菌、微生物总量、微生物Shannon多样性指数(H)、Simpson优势度指数(D)、Mc Intosh均匀度指数(U)和尖孢镰刀菌的数量、尖孢镰刀菌数量与真菌数量比、尖孢镰刀菌和拮抗菌的基因拷贝数等指标,研究了小麦蚕豆间作对接种蚕豆枯萎病病原菌(尖孢镰刀菌)、对蚕豆枯萎病发病的影响。结果表明:与单作蚕豆相比,间作蚕豆的发病率和病情指数降低86.9%和23.4%,差异显著;小麦蚕豆间作能够显著提高蚕豆根际土壤细菌、真菌、放线菌的数量及其总量,且微生物总量提升主要来源于细菌,其贡献率为83.72%,促进了蚕豆根际土壤向细菌型土壤转化;小麦蚕豆间作还能够提高蚕豆根际土壤微生物Shannon和Mc Intosh指数,有效降低Simpson指数,提高土壤微生物多样性;与单作蚕豆相比,小麦蚕豆间作蚕豆根际土壤尖孢镰刀菌数量降低了32.46%、基因拷贝数降低了17.52%,短短芽孢杆菌的基因拷贝数增加了86.06%,尖孢镰刀菌数量与真菌数量的比值降低了46.64%...     

黑垆土和红壤上两种磷效率小麦根际特征差异

以磷高效型小麦洛夫林和磷低效型小麦中国春为试材设计三室根箱试验,通过测定两品种小麦生物量、吸磷量、pH值和酸性磷酸酶活性,对比它们在两种磷水平(P 0 mg/kg、P 100 mg/kg)及两种土壤(石灰性黑垆土、酸性红壤)上的根际特征差异。结果表明,黑垆土上增施磷肥,洛夫林和中国春的总生物量分别增加了30.14%和17.75%,总吸磷量分别增加了139.24%和71.72%;红壤上增施磷肥,两小麦总生物量并没有显著增加。根际pH方面,黑垆土上,不施磷条件下,洛夫林和中国春的根际pH值分别降低0.30和0.12个单位,但在红壤上两小麦根际pH值变化不大。酸性磷酸酶方面,PO条件下,黑垆土上两小麦根际酸性磷酸酶活性差异不显著,但红壤上洛夫林酸性磷酸酶活性显著高于中国春。P100条件下,黑垆土上洛夫林酸性磷酸酶活性显著高于中国春,而红壤上两小麦酸性磷酸酶活性差异不大。试验结果表明,在黑垆土和红壤上,两种磷效率小麦根际特征存在差异。     

根际pH值与烤烟产量和质量的关系研究

主要研究根际ｐＨ值对烤烟生长及其烟叶产质量的影响。结果表明,烤烟在伸根期和旺长后对根际ｐＨ值的生长反应明显不同,微酸性的根际环境促进烟株前期生长,而微碱性则有利于烟株中后期烟叶的发育与成熟。     

不同品种小麦根际磷转化及VA菌根对小麦根际磷转化的影响

采用三室根箱研究了磷高效小麦 81( 85)-5-3-3-3及磷低效NC37两个小麦品种根际磷转化及VA菌根对根际土壤磷转化的影响。结果表明 ,磷胁迫下 ,81( 85)-5-3-3-3的吸磷量略高于NC37,两种小麦品种根际土壤均形成了明显的Olsen-P ,Ca2-P ,Ca8-P ,Al P等形态磷的耗竭区。两种小麦品种在不施磷肥和施用磷肥下接种VA菌根 ,小麦的生物量、植株磷浓度、小麦根际Olsen-P,Ca2-P ,Ca8-P,Al-P ,Fe-P的消耗量均显著增加 ;根际、非根际土壤各形态磷素的浓度梯度明显降低。     

不同形态无机磷对两种磷效率小麦根际特征的影响

以磷高效型小麦小偃54和磷低效型小麦京411为材料的砂培试验,通过测定植株生物量及吸磷量、根系形态特征、根际pH、磷酸酶活性,研究不同形态无机磷WP(KH2PO4),Al-P(AlPO4)和Fe-P(FePO4)对两种磷效率小麦根际特征的影响.结果表明,在WP处理下,两种磷效率小麦的地上部吸磷量、总吸磷量和磷吸收效率均显著高于其它处理,而其根冠比和磷利用效率却低于其他处理.除了根部吸磷量,小偃54的生物量和吸磷量有高于京411的趋势.除了WP处理,其他处理的小偃54的根冠比和地下吸磷量均高于京411.所有处理的小偃54的根长和根体积均显著高于京411,且不施磷条件(PO)下更为明显,小偃54根系长度是京411的1.6倍;此外,小偃54根系磷酸酶活性均比京411弱.除Al-P外,小偃54的根际酸化能力较京411强.由此可见,磷胁迫条件下,磷高效小麦根系形态特征改变是根际磷活化的主要机理之一,且受磷水平、磷形态及其溶解性的影响.     

不同施氮水平下小麦蚕豆间作对作物产量和蚕豆根际镰刀菌的影响

通过田间试验,研究了小麦蚕豆间作和蚕豆单作两种种植方式下,三种施氮水平(N0为0 kg hm-2,N为225 kg hm-2,N3/2为337.5 kg hm-2)对蚕豆产量和蚕豆枯萎病根际病原菌的影响,并初步探讨了间作蚕豆枯萎病根际病原菌与根际微生物区系间的关系。探讨合理的施肥及间作,使土壤微生物有利于作物的生长发育及病虫害控制。结果表明:小麦蚕豆间作显著提高了蚕豆生物量和籽粒产量,籽粒产量提高依次为:N(23.9%)>N3/(25.53%)>N(05.04%)。蚕豆根际真菌数量为间作显著高于单作,N(常规施氮水平)效果最优。间作显著抑制了镰刀菌数量,常规施氮水平镰刀菌数量最低,分别为43.0%,70.87%,76.80%。土壤中镰刀菌占真菌数量的百分比为单作明显高于间作,而且间作随着生育期变化,镰刀菌与真菌的比值逐渐降低,单作则逐渐增加。     

铝胁迫下不同耐铝性小麦根际pH值变化及其与耐铝性的关系

Al3＋是植物铝毒害的主要形态,而其活性受环境pH值的影响,H＋-ATPase通过调节根的质子分泌改变根际pH值。为探讨铝胁迫下根际pH值变化与小麦耐铝性的关系,以小麦品种ET8（耐铝型）、ES8（铝敏感型）为试验材料,采用溶液培养的方法对铝胁迫下根际pH值及根尖H＋-ATPase活性变化进行了研究。结果表明,铝处理条件下,小麦根际pH值随培养时间的延长而升高;随培养液中铝浓度的增加,根际pH值上升幅度下降,相同铝浓度处理条件下ET8根际pH值显著高于ES8。根际pH值与根尖铝含量呈极显著负相关（R2=0.932 1）,与根相对伸长率呈极显著正相关（R2=0.858 5）,表明小麦通过提高根际pH值降低根尖铝含量,减轻铝毒害。根尖H＋-ATPase活性随铝处理浓度升高而显著降低,100 μmol·L-1Al处理24 h ET8和ES8根尖H＋-ATPase活性分别为各自无铝处理的69.8%和60.0%,根尖H＋-ATPase相对活性与根际pH值呈极显著负相关（R2=0.831 9）。温度显著影响根的伸长,低温处理（9 ℃）根际pH值显著高于常温处理（25 ℃）,而根尖铝含量却显著低于常温处理。表明小麦通过根尖H＋-ATPase提高根际pH值降低铝毒害。综上所述,铝胁迫下小麦可通过提高根际pH值减轻铝毒害,不同耐铝性小麦品种根际pH值的显著差异是耐铝性差异显著的     

石灰性土壤小麦根际pH及磷动态变化的研究

本文采用网隔栽培室种植小麦,置于人工气候室内生长,对不同温度条件下土小麦根际及距根不同距离土体中ｐＨ,Ｏｌｓｅｎ-Ｐ及无机磷组分动态变化进行了研究。主要结果有:（１）根际及０～３ｍｍ土体ｐＨ较低,而３～８ｍｍ和８～５０ｍｍ土体ｐＨ较高;（２）Ｏｌｓｅｎ-Ｐ含量为根际＜０～３ｍｍ土体＜３～８ｍｍ和８～５０ｍｍ土体,温度升高,各土层Ｏｌｓｅｎ-Ｐ含量呈降低趋势;（３）距小麦根系越近,Ca2-P、Ａｌ Ｐ、Ｆｅ-Ｐ和Ca8-P含量越低,Ｏ-Ｐ和Ca10-P变化不明显;随时间延长和温度升高,Ca10-P含量有所增加,Ca2-P、Ａｌ-Ｐ、Ｆｅ-Ｐ和Ca8-P含量有所降低,Ｏ-Ｐ含量变化不大     

不同磷水平下玉米-大豆间作对红壤无机磷组分及有效磷的影响

通过2年盆栽试验,探讨不同磷水平下玉米–大豆间作根际土壤无机磷组分、土壤有效磷含量及作物磷吸收的差异,明确土壤无机磷组分、土壤有效磷与作物磷吸收之间的相互关系。试验设置玉米单作、大豆单作、玉米–大豆间作3种种植方式以及3个P2O5施用水平(0、50、100 mg/kg,分别记作P0、P50、P100),共9个处理。结果表明：与单作相比,2018年和2019年在P0、P50和P100水平下,间作显著提高玉米和大豆的籽粒产量,并显著提高玉米和大豆植株的磷素吸收量。与常规施磷水平(P100)下的单作处理相比,玉米–大豆间作在磷肥减少50%(P50)的条件下,并未降低玉米和大豆的磷吸收量与籽粒产量。3个磷水平下,间作提高了玉米和大豆根际土壤有效磷含量,而降低了根际土壤总无机磷以及Fe-P、Al-P、Ca-P、O-P的含量;同时适当增施磷肥显著提高了玉米和大豆根际土壤总无机磷及各无机磷组分的含量。本试验条件下,间作促进土壤中Fe-P、Al-P、Ca-P和O-P的活化(尤其是Fe-P),是低磷胁迫下间作土壤有效磷含量与作物磷吸收量增加的重要原因。玉米–大豆间作具有节约磷肥、维持作物产量及根际土壤有...     

两个小麦品种对根际土壤中磷的吸收

Inorganic soil phosphorus extractable with sodium bicarbonate(NaHCO3-Pi),soil pH and root hairs length and density in the rhizosphere of two winter wheat cultivars (Tritium aestivum L.cv.Shichum,Sleipner)grown on a high pH Chinese silt loam(52.7 mg NaHCO3-Pikg^-1) and a Danish sandy loam(43.4mg NaHCO3-Pi kg^-1)wer studied to assess how these wheat cultivars differed in phosphorus uptake.The rhizosphere soil pH of two wheat cultivars grown on the two soils were fairly unchanged with increasing distrance from the roo surface.However the root hairs of Shichun were 2.1 times longer than those of Sleipner,Root surface area(RSA) of Shichun increased by 192% due to root hairs whereas root hairs of Sleipner increased RSA by 68% only.Hence the root system of Shichun was in contact with more soil than that of Sleipner,even though Sleipner had a longer root,Grown at the lower pH and level of NaHCO3-Pi in the Danish soil Shichun absorbed more inorganic phosphorus than Sleipner whereas at the higher pH and level of NaHCO3-Pi in the Chinese soil there was no phosphorus uptake difference between the two wheat culivars.     

两个水稻基因型根际磷素组分、pH以及磷酸酶活性的动态变化

A rhizobox experiment with two phosphorus （P） treatments, zero-P （0 mg P kg^-1） and plus-P （100 mg P kg^-1） as Ca（H2PO4）2.H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of two rice genotypes （cv. Zhongbu 51 and Pembe） different in P uptake ability and their relationship with the depletion of soil P fractions. Plant P uptake, pH, phosphatase activity, and soil P fractions in the rhizosphere were measured. Both total dry weight and total P uptake of Pembe were significantly （P 〈 0.05） higher than those of Zhongbu 51 in the zero-P and plus-P treatments. Significant depletions of resin-Pi, NaHCO3-Pi, NaHCO3-Po, and NaOH-Pi, where Pi stands for inorganic P and Po for organic P, were observed in the rhizosphere of both Zhongbu 51 and Pembe under both P treatments. Pembe showed a greater ability than Zhongbu 51 in depleting resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and NaOH- Po in the rhizosphere. HCl-Pi and residual-P were not depleted in the rhizosphere of both genotypes, regardless of P treatments despite significant acidification in the rhizosphere of Pembe under zero-P treatment. Higher acid phosphatase （AcPME） activity and alkaline phosphatase （AlPME） activity were observed in the rhizosphere of both Zhongbu 51 and Pembe compared to the corresponding controls without plant. AcPME activity was negatively （P 〈 0.01） correlated to NaHCO3-Po concentration in the rhizosphere of both Zhongbu 51 and Pembe, suggesting that AcPME was associated with the mineralization of soil organic P.     

攀西烟区紫色土pH值与土壤养分的相关分析

对四川攀西烟区有代表性的30个紫色土样品的pH值、有机质及有效养分含量进行了测定。结果表明,攀西烟区紫色土的pH值在5．13～8．14范围内,有半数左右的土壤偏碱性;有机质、碱解氮、有效锌和有效锰的含量均随pH值的升高而降低,交换性钙的含量随pH值的升高而升高,而pH值与速效磷、速效钾、交换性镁、速效铜、速效硼间的相关性则不显著。烟区紫色土的有机质和碱解氮含量偏低,速效磷、速效钾含量中等,交换性钙、交换性镁含量丰富;部分pH值较高的土壤可能会缺乏铜、锌等微量元素;在不同pH值的土壤上硼营养均严重亏缺,建议生产中增施硼肥。     

不同磷供应水平下小麦根系形态及根际过程的变化特征

以石麦15和衡观35两个品种小麦为试验材料,应用根袋栽培方式,研究了不同施磷量对小麦根系形态和根际特征的影响。结果表明,与施磷量P2O5 0.1 g/kg相比,高量供磷（P2O5 0.3 g/kg）条件下石麦15地上部生物量和磷累积量增加幅度大于衡观35;但不施磷处理衡观35地上部生物量降低幅度小于石麦15,磷含量和累积量高于石麦15,衡观35耐低磷能力较强。土壤供磷不足时,衡观35总根长中直径0.16 mm细根所占比例高于石麦15,根系平均直径较小;而高磷供应下,石麦15根系中直径0.16 mm细根长度较长,在总根长中所占比例较高。总根长和直径0.16 mm的细根长度与植株地上部磷累积量之间呈显著正相关关系。总根长越长尤其是细根越多,有利于促进植株对磷的吸收。与非根际土壤相比,高磷供应下根际土壤有机磷含量增加,微生物量磷含量降低;而供磷不足时根际土壤碱性磷酸酶活性较高,有机磷含量较低。与施磷量P2O5 0.1 g/kg相比,高量供磷下根际土壤pH值升高、碱性磷酸酶活性下降,不施磷处理根际土壤pH值降低。本研究表明,供磷不足时,小麦根系形态和根际过程均发生适应性变化,而高量供磷条件下,小麦植株根系形态的改变因品种而异。     

Residual Effect of Phosphorus Fertilizer in a Low‐Humic Andosol with Low Extractable Phosphorus

Abstract

Phosphorus (P) fertilization is quite important for crop production grown on Andosols. Fertilizer P‐use efficiency was 17% in a long‐term wheat experiment on a low‐humic Andosol. Residual effects of P fertilization were investigated using field soils in pot experiments. Topsoil was collected from the plots with or without annual P fertilizer at the rate of 65 kg‐P ha^?1 for 23 years (nitrogen phosphorous potassium (NPK) soil and nitrogen potassium (NK) soil, respectively). There was no significant difference in dry matter of wheat and P uptake between NPK and NK soils. However, dry matter of rice and P uptake were higher in NPK soil than in NK soil. Inorganic aluminum P (Al‐P_i) and iron P (Fe‐P_i) increased in NPK soil. Increase in Al‐P_i and Fe‐P_i during 23 years contributed little to P uptake by wheat, and repeated P fertilization is indispensable to obtain acceptable grain yield.     

土壤－水分－植物体系中铅和镉的交互作用及其机制: Ⅱ. 根际中Pb-Cd的交互作用

The interaction of Pb-Cd can be observed not only in the uptake process of elements by plants and in their influence on the growth,but also in rhizosphere.The changes in extractable Cd and Pb concentrations in the rhizosphere soil of rice plants ,root exudates from wheat and wheat plant and their complexing capacity,with Pa and Cd were investigated under different Pb and Cd treatments.Results showed that the concentration of extractable Cd in the rhizosphere of rice in red soil was markedly increased by Pb-Cd interaction,It increased by 56% in the treatment with Pb and Cd added against that in the treatment with only Cd added in soil . The considerable differences in both composition and amount of root exudate from wheat and rice were found among different treatments.Pb and Cd might be complexed by root exudates ,The concentrations of free Pb and Cd in the solution were increased markedly by adding root exudate from wheat and decreased by that from rice due to Pd-Cd interaction.The distribution patterns of Pb and Cd in roots were affected by Pb-Cd interaction,which accelerated transport of Pb into internal tissue and retarded accumulation of Cd in external tissue.