冰糖橙果园土壤养分与果实品质关系的多元分析及优化方案

对湖南省74个冰糖橙果园土壤矿质养分和果实品质含量进行测定分析,运用R和LINGO软件多元统计分析筛选了影响果实品质因子的主要土壤养分因子,探明了果实品质最佳时的土壤养分优化方案。研究结果表明,调查果园中超过86.20%的样点果园土壤pH处于酸性至强酸性环境,65.52%的果园土壤缺钙,75.86%的果园缺镁,82.76%的果园缺硼。冰糖橙果实品质是多个土壤养分因子综合作用的结果,偏最小二乘回归分析表明对冰糖橙单果质量影响较大的因子为土壤碱解氮、交换性钙;果形指数主要受土壤有效磷、有效铜、有效锌和pH影响;可溶性固形物含量主要受有机质、有效铜、有效锌和pH影响;可滴定酸含量主要受土壤速效钾、有效硼和pH的影响;Vc含量主要受土壤有机质、有效磷、速效钾、交换性镁和pH的影响。线性规划求解出pH为5.50~6.50、有机质含量大于39.68 g/kg、碱解氮为169.17~170.41 mg/kg、有效磷34.50 mg/kg、速效钾158.95~160.88 mg/kg、交换性钙1954.69 mg/kg、交换性镁123.81 mg/kg、有效铁468.31 mg/kg、有效锰96.09 mg/kg、有效铜1.73 mg/kg、有效锌10.93 mg/kg、有效硼0.33~0.85 mg/kg时,冰糖橙果实品质最佳。调节土壤酸碱度,增施有机肥,及时补充钙、镁和硼肥是今后果实品质管理的关键。     

广州城市公园绿地土壤肥力及酶活性特征

采集广州市中心城区部分公园绿地表层土壤（0-20 cm）,研究了土壤pH、有机质、粘粒、氮、磷、钾含量等肥力特性和脲酶、蔗糖酶、磷酸酶活性。结果表明,广州公园绿地土壤以酸性（pH 4.5-5.5）和中性（pH 6.5-7.5）占的比例高,部分土壤呈碱性,土壤pH值较自然土壤有增高的趋势;土壤有机质含量以中等水平为主,土壤全氮、碱解氮以中等到低水平为主。土壤全磷和有效磷以中等以上水平为主,土壤全钾、速效钾以中等以上水平为主,土壤脲酶、蔗糖酶和磷酸酶活性平均分别为0.36 m g NH3-N/g,12.29 m g葡萄糖/g和2.14 m g酚/g。不同公园绿地土壤肥力特性和土壤酶活性呈现出一定的差异性。土壤脲酶、蔗糖酶和磷酸酶活性之间相关性均达到极显著水平（p〈0.01）;土壤蔗糖酶、脲酶和磷酸酶活性与土壤有机质等肥力性状之间呈显著或极显著的相关性,可以作为评价广州公园绿地土壤肥力的指标。     

桂北柑橘园土壤化学性状研究

要 ：为了解桂北柑橘园土壤养分丰缺状况,2017年在桂北7个柑橘主产县(市)选取102个代表性柑橘园采集土壤样本,对pH、有机质和10种营养元素进行定量分析。结果表明,土壤pH变幅 3.95-8.02。其中,pH值处于强酸性(pH < 4.5)、酸性(pH值 4.5-5.5)和碱性(pH值 >7.3)范围的果园分别占总样本数的24.51%、48.04%和9.80%,大部分果园土壤pH值为强酸性和酸性,有64.70%的果园土壤pH值适宜或基本适宜(pH值4.5-7.0)柑橘生长,但仅有14.71%的果园土壤pH值适宜柑橘生长(pH值5.5-6.5)。土壤有机质含量丰富,适量及以上水平的比例达86.27%。果园土壤营养元素丰缺并存,失衡比较明显,其中,有效P和有效K含量不足(低量或缺乏)的比例分别为33.33 %和30.39 %,超标(高量或过量)比例分别为21.57%和23.53%；碱解N和有效Ca含量主要在适量范围,不足比例分别为36.27%和31.37 %；有效Fe和有效Mn含量丰富,超标比例分别为64.71%和55.89%；有效Mg、Zn、Cu和B含量不足比例较高,分别为59.80 %、92.16 %、56.86 %和50.98 %。桂北柑橘产区土壤养分限制因子主要为土壤酸化,有效Mg、Zn、Cu和B含量不足,生产上应注重调节土壤酸碱度,适度增施Mg、Zn、Cu和B肥。     

施硒对紫云英生长、生理和硒积累特性的影响

通过盆栽试验,系统地研究了紫云英生长过程中对不同土壤硒浓度(0,0.125,1.25,2.5和5 mg kg~(-1))处理的生理生态响应以及不同土壤硒浓度处理下紫云英各部位硒的赋存形态,以期为紫云英的进一步综合开发利用提供科学理论依据。研究表明,随着土壤施硒浓度的升高,紫云英各项生长指标(株高、茎粗、根长、各部分鲜重和干重)呈先升后降趋势,土壤施硒浓度为0.125 mg kg~(-1)时,其各项生长指标达到最大值。随着土壤施硒浓度的增加,SOD活性、POD活性、可溶性蛋白和叶绿素含量均呈现先降后升再降的变化趋势;CAT活性呈先降后升的趋势;脯氨酸含量呈上升的趋势;可溶性糖含量则呈逐渐下降的趋势。随着施硒培养时间的延长,各处理组SOD活性和脯氨酸含量主要表现为先降后升再降的趋势;POD活性、可溶性糖、可溶性蛋白以及叶绿素含量主要表现为先升后降的趋势;CAT活性主要表现为先降后升的趋势。在土壤施硒浓度为0~5 mg kg~(-1)下,紫云英根部的硒含量为0.14~150.87 mg kg~(-1),地上部分硒含量为0.04~215.17 mg kg~(-1),其中,土壤施硒浓度≥2.5 mg kg~(-1)时,地上部分含硒量高于根部。硒在紫云英中主要以有机态(Se Met、Me Se Cys和Se Cys2)存在,占提取液总硒的81.43%~93.05%。综合研究结果认为,紫云英适合被开发为高硒材料,实际生产中以土壤施硒浓度为2.5 mg kg~(-1)为宜。     

无机硒肥对土壤有效氮含量及菠菜品质的影响

【目的】研究不同浓度亚硒酸钠(Na_2SeO_3)对土壤脲酶活性、铵态氮(NH_4^+-N)和硝态氮(NO_3~–-N)含量及菠菜品质的影响,综合分析Na_2SeO_3在土壤-根部-作物之间被吸收、转运、转化的可能路径,为生物强化生产富硒农产品及调控硒的安全水平提供参考。【方法】进行连续42天盆栽试验,共设置4个处理,每千克土施Na_2SeO_3 0 (对照)、1、10、30 mg,分别于定植后的14、28、42天测定菠菜叶可溶性糖、可溶性蛋白、维生素C、硝酸盐含量,并测定土壤铵态氮、硝态氮含量及土壤脲酶活性等指标。【结果】在菠菜生长期间,≤10mg/kg Na_2SeO_3处理可使土壤脲酶活性表现为先被激活后减弱至对照水平,土壤硝态氮含量也表现出相同的变化趋势,但铵态氮变化趋势正好相反;30 mg/kg Na_2SeO_3处理对土壤脲酶活性没有明显的影响,在整个培养时期与对照水平相当,土壤NH_4^+-N含量后期明显减少,转化成的NO_3~–-N含量明显增加,有利于菠菜吸收利用。同等Na_2SeO_3添加量条件下,Na_2SeO_3对三个取样时间菠菜叶的硝酸盐、维生素C (Vc)、可溶性蛋白、可溶性糖含量影响各异。1 mg/kg Na_2SeO_3处理组可使菠菜叶的硝酸盐含量明显增加,Vc含量先增后减,可溶性蛋白含量减少,可溶性糖含量没有变化;10 mg/kg处理组可使菠菜叶中的硝酸盐、可溶性糖含量表现为先增后减,Vc含量、可溶性蛋白含量均有不同程度增加;30 mg/kg处理组可使菠菜叶的硝酸盐含量先增后减,可溶性蛋白、可溶性糖含量减少,Vc含量没有变化。【结论】不同浓度亚硒酸钠对土壤有效氮及菠菜品质有不同程度的影响。富硒作物生产中无机硒肥施用量要综合考虑硒在作物体内的转化率及硒对作物品质影响的各项因素而确定。     

博尔塔拉河沿岸土壤重金属含量特征与有机质、pH值的关系

以博尔塔拉河沿岸表层土壤中重金属As,Cd,Ni,Cr,Pb与有机质及pH为研究对象,并对它们之间关系进行研究。结果表明:土壤中5种重金属元素As,Cd,Ni,Cr,Pb平均含量分别为22.37,52.52,27.50,0.48,28.92mg/kg。土壤有机质平均含量为27 431mg/kg。土壤pH值为6.5~7.5,平均值为6.94。研究区土壤性质与土壤重金属含量间关系复杂:有机质含量与As,Cd,Cr,Pb含量呈显著正相关,有机质易与重金属离子形成络合物,从而降低重金属离子活性,导致土壤重金属含量增加;pH值与As,Cd,Pb含量之间呈显著负相关,随pH值增大,有效态As、有效态Cd和有效态Pb在土壤中含量明显减少。通过对土壤有机质、pH与重金属含量的关系研究,发现土壤有机质、pH是影响土壤重金属含量的重要因素。     

浙西石灰岩地区土壤和稻米镉含量研究

为理解石灰岩地区农田土壤重金属积累特点及污染风险,以浙西石灰岩地区为例,随机选择了153块重金属污染农田,点对点采集了土壤和水稻样品,分析了土壤和糙米中镉的含量及土壤性状,探讨了石灰岩地区污染农田土壤与稻米镉积累特点及其与土壤性状的关系。结果表明,土壤全镉随粘粒含量的增加而增加,随土壤pH的下降而下降;土壤有效镉占全镉的比例与土壤pH呈负相关,糙米中镉含量与土壤有效镉、水溶性镉呈显著正相关;糙米中镉含量与土壤pH、有机质含量及粘粒含量均呈现显著负相关,土壤pH是影响石灰岩地区农田糙米镉积累最为重要的因素。《土壤环境质量－农用地土壤污染风险管控标准（试行）》（GB 15618—2018）的污染风险筛选值并不适用于石灰岩地区高pH的土壤。当6.5 < pH ≤ 7.5时,土壤重金属镉含量与农产品中重金属镉超标结果并不一致,其风险筛选值（0.60 mg kg?1）偏低,实际的风险筛选值可能在0.80 mg kg?1以上。土壤水溶性镉较土壤全镉和有效镉能更好地评估石灰岩地区农作物重金属镉的污染风险。     

西辽河流域苏打盐碱地养分特征及现状评价

为探究西辽河流域苏打盐碱地土壤养分现状,于2020年在花吐古拉镇(1区)和图布信苏木(2区)两个典型苏打盐碱区开展土壤养分监测,运用因子分析、聚类分析和克里金插值法对其进行单项养分评价和综合等级评价。结果表明,1区pH在7.5～8.5之间的面积占81%,2区pH在7.5～8.5之间的面积占55%、在8.5～9.5之间的面积占37%,两区全盐量在1.0～3.0 g/kg之间分别占73%和65%,盐碱化土壤类型以苏打盐化土和钠质碱化土为主。两区有机质和全氮含量较低,中等及以上等级耕地占比不足7.70%、19.23%和2.63%、25.00%,大部分耕地有机质和全氮含量处于较缺状态;有效磷和速效钾含量较高,中等及以上等级耕地占比达到84.60%、96.15%和77.63%、96.05%,因子分析结果表明,1区和2区因子1都主要表征有机质和全氮2个指标,是影响土壤养分的主要因素。IFI聚类评价结果显示,两区中等以上等级耕地占比分别为38.47%和65.79%。该结果可为西辽河流域苏打盐碱地区改善土壤养分提供理论参考。     

河南主要植烟土壤养分状况与施肥对策

在河南省不同生态类型区典型地块采集大量土壤和烟叶样品进行分析化验 ,结果表明 :河南省主要植烟土壤的 pH介于中性—微碱性范围 ,有机质和有效氮含量中等偏高 ,大部分土壤有效磷含量偏低 ,有效钾含量较高 ;中量元素钙含量过高 ,最高含量达 4 0 66mg/kg,钾钙关系失调 ;微量元素中锌较缺乏 .烟叶品质突出表现为钾素中等偏低 ,氯离子含量偏高 .为此提出该区烟草施肥中应掌握“稳氮、增磷、补钾、控钙、降氯、配微”的施肥对策     

不同改良剂对酸性烟田的改良效果及其对烤烟生长的影响

为比较碱渣、牡蛎粉和石灰对酸性烟田的改良效果及其对烤烟生长影响，本研究通过田间试验探究了三种改良剂对酸性烟田土壤酸度、烤烟产量与品质及经济效益影响。结果表明，三种改良剂施用均有效提高土壤pH，降低交换性酸和可溶性铝（Al）的含量，提升土壤交换性盐基阳离子含量。碱渣对土壤酸度的改良效果最佳，可使土壤pH提高0.38个单位，交换性酸和可溶性Al含量降低90.9%和39.8%。同时，碱渣处理中土壤交换性Ca2+和Mg2+含量分别增加了72.8%和91.9%。随着土壤性质的改善，三种改良剂均促进了烤烟的生长，提升了烟叶产量与内在品质。三种改良剂使烟叶产量增加6.0%~9.5%，上等烟比例提高4.0%~16.9%，产值增加11.7%~19.5%，净增收益增加4593.00~9270.30元/hm2，其中碱渣的增产增收幅度最大。此外，改良剂的施用优化了烤烟化学成分组成，其中牡蛎粉处理烟叶的品质最佳。总体看，利用碱渣改良酸性烟田具有广泛的应用前景，但在实际应用中，需注意控制碱渣Na和Cl元素含量。     

Effect of VA Mycorrhiza on Dry Weight and Phosphorus Content in Shoots of Cereal Crops Fertilized with Rock Phosphates at Different Soil pH and Temperature Levels

The influence of the VAM fungi Glomus macrocarpum and G. manihotis on shoot dry weight and P contents in the shoots of various graminaceous species was studied in pot culture experiments. The treatments included fertilization with different rock phosphates, four soil pH levels (pH 4.5, 5.5, 6.5, 7.5) and four soil temperatures (20, 25, 30, 35°C). The rock phosphate treatments were compared with soluble phosphate (mono calcium phosphate, MCP) and with a check (no P fertilizer, OP). Increases of shoot dry weight up to 143% could be found with mycorrhizal Triticum aestivum using Kodjari rock phosphate as P source. In the presence of VAM, Sorghum bicolor and T. aestivum fertilized with any of the rock phosphates, except Kola, produced yields comparable with those of plants fertilized with MCP, at soil pH 5.5 to 7.5 and at 25°C soil temperature. As the soil pH increased from 5.5 to 7.5 dry weight declined. Likewise, yields decreased with increasing soil temperature and at 35°C VAM showed no effect in all treatments.     

Interaction of Ph and Mn on Physiological Parameters of Brassica Oleracea L.

In the present study, interaction of 4 levels of manganese (Mn²⁺) (0, 100, 200, and 400 mM) and 4 levels of pH (4.5, 5.5, 6.5, and 7.5) were investigated on some physiological parameters of Brassica oleracea L. after 30 days of growth (15 days treatment) in hydroponic culture. Results showed that with an increase in manganese concentration, soluble carbohydrates, protein, and ascorbate contents also increased in shoots and roots of Brassica oleracea L. However, higher concentration of manganese reduced soluble carbohydrates, protein and ascorbate contents in the same plant. As manganese concentration increased, catalase activity in roots and shoots was also remarkably increased. Moreover, root peroxidase activity at pH 4.5 increased with an increase in manganese concentration and this increase was highest at pH 4.5 and 400 mM manganese concentration.     

Nonenzymatic antioxidative and antiglycative effects of oleanolic acid and ursolic acid

Oleanolic acid and ursolic acid are two triterpenes presented in several herbs. This study analyzed the content of oleanolic acid and ursolic acid in eight locally available fresh herbs, also examined several nonenzymatic antioxidant activities of these two triterpenes, and used a liposome system to evaluate the influence of temperature and pH upon the antioxidant property of these two triterpenes. The impact of these two triterpenes on the production of nonenzymatic glycative products, pentosidine and carboxymethyllysine (CML), was also evaluated. alpha-Tocopherol was used for comparison. Results showed that the content of oleanolic acid and ursolic acid in glossy privet fruit and hawthorn fruit varied from season to season and was in the range of 200-650 microg/g of fresh weight. Both oleanolic acid and ursolic acid possessed greater antioxidant activity against 2,2'-azobis-(2-amidinopropane) dihydrochloride and less antioxidant activity against 2,2'-azobis(2,4-dimethylvaleronitrile) when compared with alpha-tocopherol at equal concentration (P <0.05). At 75 and 100 degrees C, oleanolic acid exhibited greater antioxidant activity than alpha-tocopherol and ursolic acid (P <0.05). At pH 2 and pH 4, oleanolic acid and ursolic acid showed greater antioxidant activity than alpha-tocopherol (P <0.05). These two triterpenes also exhibited a dose-dependent effect in superoxide anion scavenging activity, chelating effect, xanthine oxidase inhibition activity, and reducing power (P <0.05). Oleanolic acid significantly and dose-dependently inhibited pentosidine and CML formation (P <0.05). Ursolic acid also significantly suppressed CML formation (P <0.05). These data support that these two triterpenes possessed nonenzymatic antioxidative and antiglycative properties.     

湿地松林土壤生化特性和酶活性对模拟硫沉降的响应

以亚热带湿地松人工林为研究对象,通过3种水平(对照CK:pH 6.5;低硫LS:pH 4.5;高硫HS:pH 2.5)的模拟硫沉降控制试验,分析土壤生化特性及酶活性对硫添加的响应。结果表明:(1)硫输入促进了土壤酸化,0—5 cm土层土壤pH在HS处理下显著降低,5—10 cm土层土壤pH在LS和HS处理下显著降低(P0.05);(2)硫输入对土壤有机碳库存在一定影响,土壤总有机碳(TOC)对硫输入无显著响应,但土层间的差异性显著增加(P0.05),土壤可溶性有机碳(DOC)受影响有限,5—10 cm土层微生物量碳(MBC)LS显著降低(P0.05);(3)硫输入对土壤有效氮库影响存在差异,土壤可溶性有机氮(DON)、铵态氮(NH_4~+—N)尚未表现出显著变化,土壤硝态氮(NO_3~-—N)、土壤微生物量氮(MBN)均在HS处理下显著降低,且硫输入加剧土层间的差异性(P0.05);(4)硫输入抑制了酶活性,土壤脲酶活性在HS处理下显著降低(P0.05),土壤蔗糖酶活性无显著变化,但硫输入均弱化了土层间酶活性的差异性。综合分析所有处理下的土壤生化性质和酶活性等指标发现,对硫添加响应敏感的是土壤pH和酶,土层是另外一个主要影响因子,硫添加和土层的交互作用则影响有限。采用Pearson分析得出,硫输入改变了土壤生化特性、酶活性等指标间的相关性程度。可见,酸雨对土壤酸化的影响是一个逐渐累积的过程,外源性硫添加对土壤碳氮及酶活性的影响存在一定差异,这可为硫沉降环境胁迫下森林管理提供科学依据。     

土壤主要理化性质对湘粤污染农田镉稳定效果的影响

利用盆栽试验研究了稳定剂(石灰、海泡石联合施用)对湖南、广东两省区不同性质土壤上生长的小青菜(Brassica chinensis L.)生物量、重金属吸收以及土壤pH和重金属提取态含量的影响,探讨了影响镉(Cd)稳定修复效果的土壤性质参数。结果表明:施加稳定剂对增加酸性土壤上小青菜生物量效果显著,土壤pH、有机质(OM)、全量Cd和黏粒是影响小青菜生物量变化的主要因素;土壤pH、阳离子交换量(CEC)、OM、黏粒是影响小青菜Cd含量变化的主要因素;土壤pH、CEC、全量Cd和黏粒是影响土壤提取态Cd含量变化的主要因素。     

Leaching of genetically modified Pseudomonas fluorescens through organic soils: Influence of temperature,soil pH,and roots

Summary The effects of soil temperature and bulk soil pH on the vertical translocation of a genetically modified Pseudomonas fluorescens inoculum were studied in reconstituted soil microcosms, in the presence and absence of growing Lolium perenne roots. The inoculated microcosms received one rainfall event per day (5 mm h^-1 for 6 h) for 5 days and the resulting leachate was quantitatively assayed for the presence of the modified pseudomonad. Soil temperature affected the total number of modified pseudomonads detected in the leachate over the 5 days, with significantly lower numbers detected at 25°C compared to 5°C. The bulk soil pH also affected leaching of the inoculum, with significantly greater numbers detected in the effluent at pH 7.5 than at pH 4.5. In the absence of L. perenne, greater numbers of the modified pseudomonads were detected in the pH 7.5 soil after 5 days of leaching compared to soil at pH 4.5. L. perenne roots decreased the number of cells of the inoculum that were leached and detected in the soil after 5 days of leaching. In the soil microcosms used for the pH study the distribution of the inoculum remaining with the soil was altered by L. perenne roots. At each pH value the proportion of cells detected within the soil below the surface 2 cm of the microcosms was greater in the presence of L. perenne roots. The results of this study indicate that soil temperature, bulk soil pH, and the presence of root systems are important factors in determining the extent of inoculum translocation, and should be considered in the design and interpretation of field experiments.     

模拟不同pH降雨和施氮对水耕铁渗人为土酸化的影响

室内模拟研究3个pH梯度降雨和3水平的施氮量对水耕铁渗人为土土壤酸化的影响。结果表明,不同pH降雨及施氮处理土壤的酸度累积量为4.73～15.57 mmol H+每柱,分别以pH 6.5降雨和不施氮处理、pH 2.5添加高氮量(N2)处理酸化速率为最低和最高,相同pH降雨处理下,致酸量随施氮量增加而上升;相同施氮下,不施氮处理土壤酸度累积随降雨pH降低而增加,但中施氮量(150 mg kg-1土)和高施氮量(300 mg kg-1土)下,pH 4.5处理土壤酸度累积量则小于pH 6.5处理;不同降雨及施氮处理NO3-淋溶致酸量为4.32～12.88 mmol每柱,NH+4淋溶消耗H+量为0.01～0.29 mmol每柱;正常酸沉降(pH 6.5)下,中施氮量和高施氮量处理致酸量都大于各梯度pH降雨的致酸量。以上结果表明,单施氮处理的致酸量大于单纯的酸沉降处理,而无论是降雨还是施氮,NO-3淋溶在加速土壤酸化进程中占主导作用。     

The Effect of Soil pH on Nodulation and N2-Fixation of Winged Bean Psophocarpus tetragonolobus (L) D.C. Rhizobium Strains

Nine effective Rhizobium strains of winged bean were tested for their symbiotic performance under different soil pH levels. In general, they performed best at soil pH 5.5. The performance of all the strains was poor when soil pH was either extremely low as 4.5 or high as 7.5. The strains RRIM 56, KUL-JN, KUL-Z₃ were suitable for soils with a pH range of 5.5 to 6.0. The strains KUL-Z₁, KUL-Z₂ and KUL-GP could be only used in soils with a pH of 5.5. The strains KUL-BH, KUL-6.2Z and KUL-6.9Z could be used for inoculation of soils with high pH. Isolating strains of Rhizobium by altering the original pH of the soil of Rhizobium isolation would be a good practice to obtain strains with desirable pH tolerance.     

SOME EFFECTS OF FERTILIZERS AND FARMYARD MANURE ON THE ORGANIC PHOSPHORUS IN SOILS

The amounts of P applied cumulatively to a neutral arable soil (pH 7.1–7. in 0.01M CaCl₂) at Rothamsted, as farmyard manure, alone or with superphosphate, which were converted to organic P in 100 years ranged from 18 to 44 μg P/g of soil (0–23 cm). Superphosphate alone (3300 kg P/ha) slightly lessened the total organic P in the soil. Neither farmyard manure nor super-phosphate significantly changed the amounts (38 to 42 μg P/g) of inositol penta- and hexaphosphate in these soils. In the surface layers (0–7.5 cm) of soils from permanent grassland at Rothamsted, superphosphate (3370kg P/ha) increased organic P by 134 μg P/g at pH 4.5 and 19 μg P/g at pH 6.5, about 6 and 1 per cent respectively of the P remaining from superphosphate applied cumulatively since 1858. In the sub-surface layers (7.5–23 cm) superphosphate increased organic P by 93 μg P/g at pH 4.5 and 62 μg P/g at pH 6.2, about 18 and 10 per cent respectively of the P remaining from superphosphate. The sum of inositol penta- and hexaphosphates accounted for 32 per cent at pH 4.5 and 21 per cent at pH 6.5 of the increases in organic P in the surface layers and 45 per cent and 26 per cent in the sub-surface layers at pH 4.5 and 6.5 respectively. Superphosphate (1260–2100 kg P/ha) applied intermittently or cumulatively increased total organic P by 19 to 52 μg P/g and inositol penta- and hexaphosphates by 13 to 17 μg P/g in acid tea soils (pH 3.2–3.4) from Georgia, U.S.S.R. Rock phosphate (510–1020kg P/ha) applied cumulatively had no effect on either the total organic P or the inositol P in acid tea soils (PH 3.6–3.7) from Ceylon.     

不同种植年限土壤微量元素对山银花品质的影响

[目的]探索不同种植年限土壤微量元素对山银花品质的影响,筛选山银花高产优质的最佳种植年限范围。[方法]采用野外调查和室内分析结合的方法,研究贵州省绥阳县不同种植年限山银花土壤微量元素对山银花品质的影响。[结果]不同种植年限下土壤pH值为4.67~6.01,土壤微量元素平均含量为:Cu 17.17~37.50 mg/kg,Mo 1.52~2.24 mg/kg,Mn 444.6~544.26 mg/kg,Zn 102.06~114.39mg/kg;山银花花蕾微量元素平均含量为:Cu 6.91~14.52 mg/kg,Mo 0.16~0.24 mg/kg,Mn 30.06~79.36mg/kg,Zn 12.73~23.54mg/kg;不同种植年限山银花绿原酸含量为2.988%~7.840%。[结论]土壤中Zn,Cu含量随种植年限增加而递增,Mo,Mn含量总体呈下降趋势。11~15a的山银花绿原酸含量最高,植物生长状况良好,花蕾微量元素含量总体随年限增加而增加。微量元素Cu,Zn能促进山银花的生长和绿原酸的合成,Mn元素与山银花的茎粗和叶片生长有关。