Is magnesium deficiency the major cause of needle chlorosis of Pinus taeda in Brazil?

Needle chlorosis(NC)in Pinus taeda L.systems in Brazil becomes more frequent after second and third harvest rotation cycles.In a study to identify factors contributing to yellowing needle chorosis(YNC),trees were grown in soils originating from contrasting parent materials,and soils and needles(whole,green and chlorotic portions)from 1-and 2-year-old branches and the first and second needle flush release at four sites with YNC on P.taeda were analyzed for various elements and properties.All soils had very low base levels(Ca^(2+),Mg^(2+)and K^(+))and P,suggesting a possible lack of multiple elements.YNC symptoms started at needle tips,then extended toward the needle base with time.First flush needles had longer portions with YNC than second flush needles did.Needles from the lower crown also had more symptoms along their length than those higher in the canopy.Symptoms were similar to those reported for Mg.In chlorotic portions,Mg and Ca concentrations were well below critical values;in particular,Mg levels were only one third of the critical value of 0.3 g kg^(-1).Collectively,results suggest that Mg deficiency is the primary reason for NC of P.taeda in various parent soils in Brazil.

Transmission characteristics of Tomato chlorosis virus (ToCV) by Bemisia tabaci MED and its effects on host preference of vector whitefly

The epidemiology of Tomato chlorosis virus(ToCV)in China is closely associated with its vector whitefly,Bemisia tabaci(Gennadius)MED.However,the transmission characteristics of ToCV by B.tabaci MED remain poorly understood.In this study,we analyzed:1)the horizontal and vertical transmission of ToCV by B.tabaci MED whiteflies;2)the acquisition of ToCV by male and female B.tabaci MED whiteflies after different feeding durations;3)the transmission efficacy of viruliferous male and female B.tabaci MED whiteflies after different inoculation access periods(IAPs);4)the retention of ToCV by viruliferous male and female B.tabaci MED whiteflies after a 48 h acquisition access period(AAP);and 5)the effects of ToCV on host choice of healthy or ToCV-infected tomato plant of viruliferous and non-viruliferous B.tabaci MED at different time points.Our results showed that:1)viruliferous males could not transfer ToCV to non-viruliferous females,and vice versa,viruliferous females could not pass on ToCV to non-viruliferous males.ToCV could not be detected in the F1 generation adults;2)ToCV could be detected within 4.0%of females or males after a 20 min AAP;3)ToCV could be detected in 33.3%of tomato plants inoculated by 10 viruliferous males or females with IAPs of 20 or 30 min;4)the maximum retention time in females was 7 and 5 days in males;and 5)non-viruliferous B.tabaci MED did not show a preference for ToCV-infected tomato plants or healthy tomato plants.However,viruliferous B.tabaci MED whiteflies did prefer to settle on healthy tomato plants over ToCV-infected tomato plants.These findings will be helpful to better understand the epidemiology of the recently emerged plant virus,ToCV,in tomato fields in China.

Effect of slow-release iron fertilizer on iron-deficiency chlorosis, yield and quality of Lilium davidii var.unicolor in a two-year field experiment

Iron deficiency chlorosis of Lilium davidii var. unicolor is often the case in practice in alkaline soils of northwest region of China. It is difficult to control iron chlorosis because of high cost and short effective work time of conventional iron fertilizers. In this study, a 2-year field experiment was conducted to evaluate the effects of two slow-release fertilizers on the suppression of iron deficiency chlorosis, soil chemical properties, and the yield and quality of L. davidii var. unicolor. Results show that both coated slow-release iron fertilizers and embedded slow-release iron fertilizer effectively controlled iron-deficiency chlorosis. The application of slow-release iron fertilizers significantly increased plant height and chlorophyll content of L. davidii var. unicolor at different growth stages. Furthermore, coated iron fertilizer application significantly increased starch, protein, soluble sugar and vitamin C content of L. davidii var. unicolor, and it also significantly improved total amino acid content, with increases in essential amino acids(Trp, Leu, Lys, Phe, Val, and Thr contents) and in nonessential amino acids(Asp, Glu, Cit, Ihs, Acc, Ala, Pro, and Cys contents). It was concluded that application of coated slow-release iron fertilizer could be a promising option for suppression of iron deficiency chlorosis and deserves further study.

Occurrence Reasons and Integrated Control of Physiological Chlorosis ofCinnamomum camphora L. in Urban Area of Pingdingshan City

The relevant factors for physiological chlorosis of Cinnamomum camphora L. in Pingdingshan were studied combining with references and production sur- vey. The resuhs showed that the disease was the integrated results of soil environment, planting situation, microenvironment construction and maintenance manage- ment. Therefore, the countermeasures of ＂prevention first, restore tree vigor; integrated control, enhance tree vigor＂ were proposed. Chlorosis of C. camphora had been basically controlled after four years, and the control effect was obvious.

Manganese toxicity-induced chlorosis in sugarcane seedlings involves inhibition of chlorophyll biosynthesis

Manganese(Mn)toxicity-induced leaf chlorosis limits crop production in acidic soils,but its underlying mechanisms remain unknown.The effects of excessive Mn on chlorophyll(Chl)biosynthesis in sugarcane(Saccharum officinarum L.)leaves were investigated.Under Mn treatment,Chl concentration decreased with Mn accumulation and chlorosis appeared in expanding leaves.Before that,levels of the initial Chl precursor 5-aminolevulinic acid(ALA)and its downstream intermediates decreased,whereas magnesium-protoporphyrin IX monomethyl ester(MgPME)accumulated.Overaccumulation of Mn in leaves downregulated the ALA biosynthetic gene GluTR(encoding glutamyl-tRNA reductase)and MgPME conversion gene MgPMEC(encoding MgPME cyclase),upregulated the ALA biosynthesis inhibitor FLU(encoding FLUORESCENT),but had no significant effect on the expression of other Chl biosynthetic genes.The above Mn-induced changes of Chl precursors and expression of corresponding genes commenced before the Chl decline and leaf chlorosis,and were reversed by ALA supplementation.Thus,excessive Mn-induced chlorosis in sugarcane is mediated by a Chl-biosynthesis disorder resulting from the inhibition of ALA synthesis and MgPME conversion.

How Raised Beds and Fe-Chelate Affect Soybean Iron Deficiency Chlorosis and Yield

Water-logging and the inability to take up sufficient iron (Fe), causing iron deficiency chlorosis (IDC) in soybean (Glycine max, L. Merr.), can be major yield reducing factors in certain soils in the northern USA and Manitoba, Canada, soybean growing regions. The objective of this research was to evaluate soybean IDC, biomass production, and yield with seeding on raised beds and seed application of the Fe-chelate compound ortho-ortho-Fe-EDDHA. In six environments, soybean were seeded on raised beds and conventionally prepared seedbeds (flat) and with a factorial arrangement of five cultivars (within adapted maturity group 0.1 to 0.9 and variable IDC tolerance) and seed applied Fe-EDDHA using rates of 0 kg·ha−1 and 3.36 kg·ha−1. There were no significant interactions between the factors tested. The plant population was 27% higher on the raised beds compared with flat, and yield was 6.3% higher (2893 kg·ha−1 vs. 2722 kg·ha−1). Total dry plant biomass on raised beds was 9.8% greater compared with flat. The plant population with seed applied Fe-EDDHA was 10.6% lower compared with no application. However, the IDC score was significantly lower 2.2 vs 2.4 (1 = green, 5 = dead) for Fe-EDDHA seed application. Yield and plant biomass were not significantly different between Fe treatments. Raised beds offer an opportunity for soybean growers to reduce the negative influence of excessive water. Further research is needed to determine the long-term effect of raised beds on plant development, IDC expression, and yield. The application of Fe-EDDHA remains a partial solution and should therefore be combined with other methods to reduce IDC. Further research should study other Fe-EDDHA application rates and methods.

‘阳光玫瑰’葡萄黄化现象及防治技术

‘阳光玫瑰’葡萄因具有优良的品质和较高的栽培效益,近年来种植面积迅速增加,已成为我国葡萄主栽品种之一。然而在栽培过程中黄化现象时有发生,严重影响了产量和品质。为此,在生产实践基础上,结合前人的研究,本文针对‘阳光玫瑰’葡萄黄化的成因和造成的危害,提出了防治黄化现象的技术措施,以期为‘阳光玫瑰’葡萄生产提供支撑。

基于缺铁诊断指标筛选的猕猴桃叶片黄化诱因分析

[目的]筛选适宜的缺铁诊断指标,据此分析导致陕西关中地区猕猴桃园叶片黄化的主要因子,并利用施肥矫治试验对该因子进行验证,为猕猴桃叶片黄化防控提供理论依据。[方法]在陕西关中地区,依据叶片黄化后土施Fe-EDDHA可以复绿确定了3个缺铁猕猴桃果园,采集当年强旺营养枝顶端第2~3个叶片,共采集不同黄化度叶片64份,缺铁叶片样品的黄化度以SPAD值表征,将SPAD值与5个缺铁诊断指标进行相关分析。在关中地区选择5个健康果园、80个出现不同程度黄化症状的猕猴桃果园,采集叶片样品,将黄化果园叶片按照黄化程度分为绿叶、轻度黄化叶和重度黄化叶,测定12种元素、活性铁和硝态氮含量及SPAD值,并将其与SPAD值进行相关分析。在85个果园各采集1份土壤样品,分析其基础理化性状。选择两个黄化果园进行施肥矫治效果验证。[结果]64份缺铁黄化叶片中,鲜样邻二氮菲浸提铁与其SPAD值的相关性明显高于干样全铁、0.1 mol/L盐酸浸提铁、1 mol/L盐酸浸提铁和鲜样1 mol/L盐酸浸提铁,说明鲜样邻二氮菲浸提铁最适于猕猴桃缺铁的黄化诊断。健康园绿叶和黄化园绿叶中所测的12种元素、活性铁和硝态氮含量均无显著差异。SPAD和邻二氮菲浸提铁含量的顺序为黄化园绿叶>轻度黄化叶>重度黄化叶,而叶片硝态氮、磷、钾和硼含量则相反。轻度和重度黄化叶钙、全铁和锰含量低于绿叶。相关分析表明,猕猴桃叶片SPAD与叶片邻二氮菲浸提铁、全铁、锰和钙含量正相关,而与叶片钾、磷、硝态氮、全氮、硼、铜等含量负相关。随机森林和通径分析进一步表明,与猕猴桃叶片黄化关系最密切的指标为邻二氮菲浸提铁、钾及硝态氮。线性加平台函数拟合表明,邻二氮菲浸提铁5.084 mg/kg是猕猴桃叶片缺铁黄化诊断的临界值。土壤分析结果表明,黄化园土壤pH和碳酸氢根含量均偏高,而速效钾和硝态氮含量均适宜,说明土壤重碳酸盐诱发缺铁很可能是导致叶片黄化的主要原因。与健康园相比,黄化园土壤阳离子交换量偏低,说明叶片黄化还与土壤阳离子交换能力不足有关。施用Fe-EDDHA和蓝铁矿[Fe_(3)(PO_(4))_(2)·8H_(2)O]均可提高叶片SPAD和邻二氮菲浸提铁含量,降低叶片钾和硝态氮含量,从而矫治猕猴桃叶片缺铁黄化。[结论]叶片鲜样中邻二氮菲铁最适于猕猴桃缺铁黄化诊断,其临界浓度为5.084 mg/kg。陕西关中地区猕猴桃园叶片黄化主要是由土壤重碳酸盐诱发缺铁所致,且与土壤阳离子交换能力不足有关;黄化叶中钾和硝态氮的累积是由缺铁造成的。因此,生产上应注意黄化园铁肥的补充和土壤阳离子交换能力的提升。

基于DRIS法的大花序桉苗期“黄化症”苗圃营养状况诊断

植物营养诊断是评估大花序桉营养状况的可靠、便捷方法。本研究采用诊断施肥法(DRIS),对广西崇左发生“黄化症”的大花序桉苗木营养状况进行调查、诊断。结果表明,大花序桉苗期叶片营养元素含量与“黄化症”之间密切相关。大花序桉叶片苗期养分供给状况以及需肥顺序为Fe>P>N>Mg>K>B>Cu>Zn>Mn>Ca。黄化症的叶片N、P、Fe和Ca诊断指数均小于0,属于缺乏水平,是影响苗木黄化的关键因子,而其他营养元素的DRIS诊断指数均为正值,供给较为充足。大花序桉苗期的各营养元素的适宜范围为N(7.50~10.80)g/kg、P(1.25~2.98)g/kg、K(10.37~30.64)g/kg、Ca(5.13~23.631)mg/kg、Mg(1.55~3.82)mg/kg、Cu(4.53~8.34)mg/kg、Zn(46.57~62.83)mg/kg、Fe(140.03~226.31)mg/kg、Mn(252.95~426.99)mg/kg、B(18.80~39.85)mg/kg。

广西番茄花叶病毒和番茄褪绿病毒的分子鉴定

为明确引起广西番茄呈现褪绿斑驳和花叶症状的病毒病原,采集4个疑似病毒感染的番茄样品,利用小RNA深度测序、RT-PCR、序列分析、遗传进化树的构建等方法对样品进行鉴定及遗传进化分析。研究结果发现,小RNA数据中的41条contigs分别被注释为番茄花叶病毒(tomato mosaic virus,ToMV)和番茄褪绿病毒(tomato chlorosis virus,ToCV);RT-PCR证实了s RNA的结果,且所有样品均存在ToMV和To CV的复合侵染。通过拼接获得ToMV和ToCV RNA2的近全基因序列,ToMV近全基因序列为6383 bp,命名为ToMV-GX;ToCV RNA2的近全基因序列为8031 bp,命名为ToCV-GX。进化树分析发现,本研究获得的ToMV-GX与ToMV中国山西、内蒙古、呼和浩特3个分离物处于一个分支,说明其具有较近的亲缘关系;ToCV-GX与ToCV中国台湾、广东分离物处于一个大分支,说明具有较近的亲缘关系。上述结果证实,引起广西番茄呈现褪绿斑驳和花叶症状的病原是To MV和ToCV,本研究是ToMV和ToCV复合侵染广西番茄的首次报道。

叶片黄化对葡萄生理和果实品质的影响

为了探究叶片黄化对葡萄生理和果实生长的伤害机制,试验以生长在河南省荥阳市蔡寨村表现黄化症状的4年生‘阳光玫瑰’成龄树为试材,通过测定并分析黄化植株与正常植株的茎叶生长量、叶绿素含量、光合特性、叶绿素荧光参数、叶片解剖结构以及果实品质和产量的变化特征,考察叶片黄化后对葡萄生长量、光合指标、叶绿素荧光特性以及果实品质的影响,以期为葡萄开展黄化矫正栽培提供参考依据。研究表明,(1)黄化植株叶片的叶绿素含量、叶片大小、叶片重量、新梢长度、枝条粗度均显著降低;(2)黄化植株叶片的净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s))显著下降,而胞间CO_(2)浓度(Ci)显著上升;(3)黄化植株叶片的叶绿素荧光参数初始荧光(Fo)、光下最小荧光产量(Fo′)、最大荧光产量(Fm)、相对电子传递速率(ETR)、实际光合量子产量Y(Ⅱ)均比正常植株显著降低;(4)黄化植株叶片厚度、栅栏组织厚度和栅海比比正常植株显著升高,上表皮厚度和海绵组织厚度比正常植株显著降低;(5)黄化植株果实产量、穗重、果实大小、可溶性固形物含量以及单粒重量均比正常植株显著降低。因此,葡萄黄化植株的叶片光合作用和枝叶生长发育受到显著抑制,果实的产量和品质均显著下降。

阳光玫瑰葡萄叶片黄化原因及矫正效果研究

【目的】探寻阳光玫瑰葡萄叶片大面积普遍黄化的原因以及行之有效的矫正方案,为切实解决葡萄叶片黄化问题提供参考依据。【方法】以出现黄化症状的阳光玫瑰葡萄植株为材料,调查郑州地区24个黄化葡萄园,测定其理化指标以及土壤不同形态铁含量。分析土壤和叶片元素含量、FCR酶活性、根系铁含量以及根系活力的差异,初步确定叶片黄化的原因。以盆栽试验的方法,用NaHCO_(3)和NaOH处理后观察黄化情况,测定并分析叶片铁含量、FCR酶活性及根系铁含量的差异,进一步确定黄化的原因。设计3种矫正方案对黄化植株进行处理,通过观察复绿情况和叶片营养元素变化,验证叶片黄化的发生原因,探索可行的矫正方案。【结果】调查结果表明,所有园区土壤均呈碱性,且大部分黄化园区土壤有效铁并不缺乏,植株黄化程度与土壤pH值、EC值、有机质含量以及全铁和有效铁含量相关性均不显著。在大田试验中,黄化植株与正常植株的土壤均偏碱性,土壤中氮以硝态氮为主。黄化植株根际土壤中速效元素氮、磷、铁、铜、锌含量均显著低于正常植株的土壤,速效钾含量显著高于正常植株的土壤,二者土壤全铁含量差异不显著。不同程度黄化叶片中氮、磷、钾、有效铁以及铜、锌的含量均显著低于正常植株。黄化植株根系中全铁含量显著高于正常植株。正常叶片全铁含量显著高于黄化叶片,不同程度的黄化叶片全铁含量随黄化程度增大而增加。黄化和正常植株根系活性无显著差异,黄化叶片FCR酶活性受到显著抑制。在盆栽试验中,NaHCO_(3)溶液处理的植株叶片发生黄化,而用pH值为9的NaOH溶液处理的植株并未发生黄化现象。NaHCO_(3)诱导发生黄化的植株根系铁含量、叶片铁以及FCR酶活性与大田试验结果相似,黄化植株根系铁大量积累,且显著高于正常植株,叶片FCR酶活性受到抑制,黄化叶片全铁含量显著高于正常叶片。矫正试验的3种方案处理后有不同程度复绿,其中以根施铵肥配柠檬酸复绿效果最好,叶面喷施铁肥配柠檬酸次之,单纯叶面喷施柠檬酸较差。各处理复绿叶片中氮、磷、钾、锌、铜元素含量相较于黄化对照均有下降,但叶面喷施柠檬酸处理叶片中总铁含量依然高于根施铵肥配柠檬酸处理。【结论】由于土壤高pH值诱导,HCO_(3)^(-)和NO_(3)^(-)在土壤中大量积累,使根和叶中铁还原酶活性降低,植株对铁元素吸收和转运受到抑制,积累在根系和叶片质外体的铁元素不能顺利被还原转运到根细胞和叶肉细胞,最终导致阳光玫瑰叶片缺铁黄化。黄化矫正方案以根施铵肥和酸性物质、解除根系铁还原受到的抑制作用复绿效果最佳。

不同矿化水对纳米纤维素-铁螯合物的影响及其在矫治梨缺铁黄化中的应用

采用不同矿化度水质配制纳米纤维素(NC)-铁(Fe)螯合物(NC-Fe),研究不同矿化度水对NC-Fe的螯合及其对梨树缺铁黄化矫治的影响。结果表明:用矿化度为750、1500、3000 mg·L^(-1)的矿化水配制的NC-Fe悬浮液,其纳米粒子粒径、Zeta电位值随水矿化度的增加而变大;随水矿化度的升高,纳米螯合物的生物活性降低,与NC-Fe处理相比,由750、1500、3000 mg·L^(-1)矿化水配制的NC-Fe处理叶片活性铁含量分别下降9.1%、23.6、40.3%。此外,与NC-Fe处理相比,随水矿化度的升高,其配制的NC-Fe处理叶片内铁蛋白基因Fer1的相对表达量显著下降。综上,当水矿化度小于1500 mg·L^(-1)时,矿化度对NC-Fe的螯合有限,但仍能促进叶片有效铁含量提升,对铁蛋白基因Fer1的表达有诱导作用,故可在生产中使用Ⅲ类以下的矿化水配制NC-Fe,用于矫治梨树缺铁黄化。

平衡针灸联合益气维血胶囊在萎黄病患者中的应用效果

目的探讨平衡针灸联合益气维血胶囊在萎黄病患者中的应用效果。方法回顾性分析2021年1月~2022年12月于门诊就诊的60例萎黄病患者作为研究对象,按照随机数表分为对照组及观察组。对照组30例进行常规治疗,观察组30例进行平衡针灸联合益气维血胶囊治疗。比较两组患者临床疗效,治疗前后血常规指标。结果治疗前对照组和观察组的MCHC、MCV、Hb水平比较差异均无统计学意义(P>0.05);治疗后与同组治疗前相比,两组MCHC水平无明显变化(P>0.05);治疗后与同组治疗前相比,两组MCV、Hb水平均明显升高,且与对照组相比,观察组明显更高(P<0.05)。对照组的临床有效率和治疗满意度分别为73.33%、66.67%,观察组分别为96.67%、90.00%,与对照组相比,观察组明显更高(P<0.05)。结论平衡针灸联合益气维血胶囊治疗可显著改善萎黄病患者的血常规指标水平,提高治疗效果,进而提高患者满意度。

番茄褪绿病毒研究进展

番茄褪绿病毒(tomato chlorosis virus, ToCV)属于长线形病毒科(Closteroviridae),毛形病毒属(Closteroviridae),可以侵染番茄、马铃薯、黄瓜等多种农作物,自2011年在我国山东发现该种病毒以来,目前已经逐步蔓延至多个省份,对我国番茄的安全生产造成了重大损失。本文从番茄褪绿病毒的基本特点、检测方式、防治措施等多方面进行归纳总结,以期为番茄褪绿病毒的防治工作以及抗番茄褪绿病毒品种育种奠定基础。

基于猕猴桃叶片黄化问题的土壤分析研究

随着种植面积的扩大,叶片黄化成为猕猴桃生长中常见的现象,严重影响猕猴桃生产的效益。选取陕西省周至县正常和发生叶片黄化的猕猴桃果园各6个,取样并测定了果园土壤的pH和养分含量。结果表明,发生叶片黄化的猕猴桃果园中土壤的pH平均偏高0.99,土壤中有机质的含量是正常果园的32.3%,且中微量元素匮乏。通过对土壤中各养分之间的相关性分析,提出采取调节土壤的pH、增施有机肥和中微量元素等措施,来改善猕猴桃果树叶片黄化的状况,以提高猕猴桃的产量和品质。

警惕番茄褪绿病毒在我国的传播和危害

番茄褪绿病毒(Tomato chlorosis virus,ToCV)侵染番茄引起番茄褪绿病毒病。发病植株下部叶片黄化、脉间褪绿、边缘轻微卷曲,叶片光合作用显著降低,果实变小,产量和品质明显下降。该病毒最早于1998年在美国佛罗里达州发现,随后在世界多地陆续报道。我国首先于2004年在台湾报道,2013年又在北京和山东发现并鉴定了该病毒,同时在辣椒上检测到该病毒。ToCV属于长线形病毒科(Closteroviridae)毛形病毒属(Crinivirus)成员,基因组为二分体正义单链RNA,由粉虱传播。经初步调查和检测,ToCV在我国北京、山东、河北、天津等省市相继发生,给当地番茄生产造成了严重危害。ToCV传播迅速,成为我国番茄生产中又一重要病毒,防控形势严峻。基于以上原因,建议有关部门立即采取相应预防和防治措施,组织开展相关研究和攻关,控制该病毒在我国的传播和危害。

植物吸收利用铁的机理

根据植物铁营养的一些研究进展 ,论述了植物对铁的吸收和运输机理以及 HCO- 3 、N。

不同铁制剂对石灰性土壤条件下猕猴桃缺铁黄化的矫治效果

为明确陕西杨凌渭河滩地猕猴桃出现黄化现象的原因,通过对喷施铁制剂矫正效果的比较,筛选出理想的铁制剂用于果树缺铁黄化病防治。以陕西杨凌西桥村出现缺铁黄化的猕猴桃园为研究对象,采用土壤诊断和叶片诊断等方法确定黄化的原因,并以清水为对照,喷施不同铁制剂(硫酸亚铁、柠檬酸铁、复合氨基酸铁、乳酸亚铁和腐殖酸铁)进行矫治,检测其对猕猴桃叶片叶绿素和有效铁含量及果实品质的影响。结果表明,猕猴桃黄化原因不仅仅是由于土壤有效铁含量低,还与植株吸收能力不同有关。由于植株过多吸收P、K、Zn、Mn等元素,引起养分不平衡而导致对铁吸收产生拮抗作用也是产生缺铁黄化的原因之一。不同铁制剂对猕猴桃黄化的矫治效果有差异,其中以柠檬酸铁和复合氨基酸铁的处理效果最好,显著提高了猕猴桃叶片的叶绿素和有效铁含量以及果实中维生素C、可溶性固形物、全铁的含量,有效改善了果实品质。在供试的几种铁制剂中,柠檬酸铁和复合氨基酸铁是矫治果树缺铁黄化的最理想制剂。

甘蔗幼苗失绿的土壤营养特性初探

【目的】研究影响甘蔗幼苗失绿的土壤因素,为克服失绿现象提供科学依据。【方法】对广西南宁、崇左、来宾等地甘蔗发生幼苗失绿问题的土壤营养进行调查研究,分析土壤pH值、铁、铝、锰和有机质含量等与甘蔗失绿现象的关系。【结果】甘蔗幼苗失绿病发土壤多属强酸性土壤,活性铝、交换性锰水平较高;土壤有机质、氮磷钾全量和有效水平总体上属于中高等水平;土壤有效铁含量不高,而与土壤有机质含量呈极显著正相关。【结论】甘蔗幼苗失绿可能与强酸性土壤中过多的活性铝、锰及高效整合铁有关。