Influence of B-permeated goethite on soil B fraction and its availability to rape seedlings (brassica napus L.)

The purpose of the study was to determine the effect of boron (B)-permeated goethite on soil B fractionation and the availability of this B fraction to rape seedlings (Brassica napus L.). For this purpose, goethite and two kinds of B-permeated goethite were synthesized and their processes in soil were simulated. Plant availability of B adsorbed or occluded on goethite was investigated with rape seedling. Results found that both ad-B-goethite and oc-B-goethite significantly increased the water soluble B (WS-B), specifically adsorbed B (SPA-B), B occluded in amorphous iron (Fe) and aluminum (A1) oxides (AMO-B) and crystalline Fe and Al oxides (CRO-B) content in the soil, compared with ordinary goethite. Also the B-permeated goethites improved B content of the rape seedling and therefore enhanced the rape shoot and root dry weight. Correlation analysis demonstrated that water soluble B (WS-B) plays the most important role in rape B uptake and accumulation, moreover the specifically adsorbed B (SPA-B), nonspecifically adsorbed B (NSA-B), amorphous Fe and A1 oxides (AMO-B) was also significant correlated with the B content or B accumulation of the rape.     

The use of boron isotopes to evaluate boron uptake by rape grown in acid soil treated with boron containing goethite

Boron (B), taken up by plants, comes mainly from boron adsorbed by soil constituents, in particular by metal hydrous oxides, organic matter, and edges of clay minerals. The extent and availability of B adsorbed or occluded by soil minerals is unknown due to the lack of a methodology for probing activity of this type of boron. In this study, ¹⁰B labeled boron‐containing goethites, i.e., goethite with adsorbed B (ad‐B‐goethite) and occluded B (oc‐B‐goethite), were added individually to an Ultisol for pot experiments to probe soil B bioavailability. The fraction of soil B extracted from B‐containing goethite showed a sigmoidal extraction pattern similar to that of B adsorbed on soil minerals. The rape seedling uptake of B from ad‐B‐goethite treatment of soil was close to that from soil background (50%), while that from oc‐B‐goethite treatment of soil was about 66%. The B absorbed from both B‐containing goethite and soil was mainly accumulated in the shoot; less than a tenth of the B was accumulated in the root. In summary, the behavior of B in B‐containing goethite was generally similar to that of soil B, indicating that B containing goethite can be used to probe migration of B from soil to plant.     

EFFECT OF BORON-DOPED GOETHITE ON SOIL ACIDITY,DIFFERENT FORMS OF MANGANESE IN RED SOIL AND THE GROWTH OF RAPE (BRASSICA NAPUS L.) SEEDLINGS

Rape (Brassica napus L.) seedling pot experiments were performed with a red soil treated with goethite which had boron (B) either adsorbed (ad-B-goethite) or occluded (oc-B-goethite). Soil acidity, different forms of manganese in the soils and different elements content of the rape seedlings were determined. It was found that the addition of boron-containing goethite to the soils resulted in increased rape growth, elevated soil pH and decreased exchangeable acidity. Compared with the control, boron-containing goethite elevated the content of exchangeable manganese (Mn) (EXC-Mn), organic matter bound Mn (OM-Mn), reducible oxide Mn (RO-Mn) and residual Mn (RES-Mn) which were difficult to use for plant. Low labile organic matter was significantly correlated with easily reducible oxide Mn (ERO-Mn) (P < 0.01) and RO-Mn (P < 0.05). Middle organic matter and soil pH was significantly (P < 0.05) correlated with RES-Mn. Stepwise regression was used to select the combination of variables that best estimates shoot and root dry weight of rape seedling. Among them, soil pH, EXC-Mn, OM-Mn, RO-Mn and RES-Mn significantly influenced the dry weight of rape seedlings. The addition of boron-containing goethite improved the uptake of iron (Fe), calcium (Ca), magnesium (Mg), and copper (Cu) element and decreased the uptake of Mn and zinc (Zn) element in rape seedling. The results suggested that boron-containing goethite could provide a better soil acidity environment for plant growth; it was also an important agent increasing a part of manganese difficult to use for plant and reducing the activity of soil manganese, which was beneficial to altering rape seedling growth.     

Response of Soil and Plant to Boron-Doped Aluminum Hydroxide

The aims of this work are to test whether boron (B) may alleviate soil acidification and aluminum (Al) phytotoxicity to rape (Brassica napus L.) in acidic soil. The Al hydroxide that reacted with borax was called ad-B-Al hydroxide. Point of zero charge (PZC) of Al hydroxide (pH 4.86) was greater than that of ad-B-Al hydroxide (pH 4.68). Compared with the control, ad-B-Al hydroxide raised the soil pH significantly by 0.10 pH units. Rape was planted in the control soil, the soil treated with Al hydroxide, and the soil treated with ad-B-Al hydroxide. It was found that the B content of the soil and rape seedlings grown on the soil treated with ad-B-Al hydroxide was greater than the others. Biomass production of rape seedlings grown in the soil treated with ad-B-Al hydroxide was significantly increased compared to that in the others. These demonstrated that ad-B-Al hydroxide can be an important source of B for plants and alleviate acidity of acidic soils because it can decrease exchangeable acid and Al toxicity in soil significantly.     

Adsorption of Cr(VI) ion on synthetic hydrated oxides of iron

Abstract

The adsorption of Cr(VI) ion on synthetic hydrated oxides of iron (goethite (α-FeOOH) and lepidocrocite (γ-FeOOH)) with different crystallinities was studied in order to remove the Cr(VI) ion from polluted water. At pH 4.5, the amounts of the adsorbed Cr(V1) ion on goethite and lepidocrocite were 51.9 and 62.2 mmol g^?, respectively. Probably, this is due to the fact that the structure of lepidocrocite is more open than that of goethite. Lepidocrocite, therefore, is more effective for the removal of Cr( V1) ion from Cr(Vl)-contaminated and acidic groundwater and sewage.     

Adsorption of glycerophosphate on goethite (α‐FeOOH): A macroscopic and infrared spectroscopic study

Adsorption, desorption, and precipitation reactions at environmental interfaces govern the bioavailability, mobility, and fate of organic phosphates in terrestrial and aquatic environments. Glycerophosphate (GP) is a common environmental organic phosphate, however, surface adsorption reactions of GP on soil minerals have not been well understood. The adsorption characteristics of GP on goethite were studied using batch adsorption experiments, zeta (ζ) potential measurements, and in situ attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR). GP exhibited fast initial adsorption kinetics on goethite, followed by a slow adsorption. The maximum adsorption densities of GP on goethite were 2.00, 1.95, and 1.44 μmol m^?2 at pH 3, 5, and 7, respectively. Batch experiments showed decreased adsorption of GP with increasing pH from 3 to 10. Zeta potential measurements showed a remarkable decrease in the goethite isoelectric point upon GP adsorption (from 9.2 to 5.5), suggesting the formation of inner‐sphere surface complexes. In addition, the ATR‐FTIR spectra of GP sorbed on goethite were different from those of free GP at various pH values. These results suggested that GP was bound to goethite through the phosphate group by forming inner‐sphere surface complexes.     

镉在针铁矿、针铁矿-腐植酸复合胶体中吸附解吸行为比较研究

采用批平衡试验法,比较研究了重金属镉在针铁矿和针铁矿-腐植酸复合胶体中的吸附热力学和动力学行为。结果表明,在试验浓度范围内,两种吸附剂对Cd2＋的等温吸附特征均可用Langmuir、Freundlich和Linear方程加以描述。其中以Langmuir方程的拟合效果最佳,线性相关系数为：0.991、0.999,由此推导出的最大吸附量分别为41.667和45.455mg·g^-1,表明腐植酸与针铁矿复合胶体较单一针铁矿的吸附力有所提高,且所吸附的镉均难以解吸,平均解吸率分别为5.871%和1.068%。胶体对Cd^2＋的吸附是一个快速反应过程,4h达到吸附平衡。Elovich方程是拟合吸附动力学过程的最优方程（相关系数分别为0.987和0.997）。通过计算镉在针铁矿和针铁矿-腐植酸复合胶体中的吸附自由能变化量（ΔG的绝对值均〈40kJ·mol^-1）,推测镉在两种胶体中的吸附为物理吸附过程,其吸附机理可能有氢键、偶极作用力和范德华力等作用,而不存在化学键合作用。     

Iron oxide‐humic acid coprecipitates as iron source for cucumber plants

In soil, iron (Fe) solubility depends on complex interactions between Fe minerals and organic matter, but very little is known about plant availability of Fe present in Fe oxides associated with humic substances. For this purpose, this study investigates the effect of Fe mineral crystallinity in the presence of humic acids (HA) on Fe availability to plants. Four Fe–HA mineral coprecipitates were prepared, either in the presence or absence of oxygen, i.e., two goethite (G)‐HA samples containing large amounts of Fe as nanocrystalline goethite and ferrihydrite mixed phases, and two magnetite (M)‐HA samples containing crystalline magnetite. Bioavailability studies were conducted in hydroponic systems on cucumber plants (Cucumis sativus L.) grown under Fe deficient conditions and supplied with the Fe–HA coprecipitates containing goethite or magnetite. Results showed that plants grown in the presence of Fe–HA coprecipitates exhibited a complete recovery from Fe deficiency, albeit less efficiently than plants resupplied with Fe‐chelate fertilizer used as control (Fe‐diethylene triamine penta acetic acid, Fe‐DTPA). However, the supply with either G‐ or M–HA coprecipitates produced different effects on plants: G–HA‐treated plants showed a higher Fe content in leaves, while M–HA‐treated plants displayed a higher leaf biomass and SPAD (Soil–Plant Analysis Development) index recovery, as compared to Fe‐DTPA. The distribution of macronutrients in the leaves, as imaged by micro X‐ray fluorescence (µXRF) spectroscopy, was different in G–HA and M–HA‐treated plants. In particular, plants supplied with the poorly crystalline G–HA coprecipitate with a lower Fe/HA ratio showed features more similar to those of fully recovered plants (supplied with Fe‐DTPA). These results highlight the importance of mineral crystallinity of Fe–HA coprecipitates on Fe bioavailability and Fe uptake in hydroponic experiments. In addition, the present data demonstrate that cucumber plants can efficiently mobilize Fe, even from goethite and ferrihydrite mixed phases and magnetite, which are usually considered unavailable for plant nutrition.     

Effects of Crystal Modification on the Binding of Trace Metals and Arsenate by Goethite (7 pp)

-  Dedicated to Prof. Dr. Ulrich Förstner on his 65th birthdayGoal, Scope and Background   Goethite (&#945;-FeOOH) as the most frequently occurring iron oxide in the environment plays a significant role in the binding of inorganic pollutants. Accordingly, synthetic goethite is used for the purification of contaminated water. Goethite crystals can be prepared in different shape as porous and non-porous forms. The mineral can also be modified by partial substitution of structural Fe+3 for different foreign elements. The biggest possible substituent known so far is Cd+2 which causes a strong expansion of the unit-cell parameters. An incorporation of Pb+4 generates a permanent positive charge. Goethites with these morphological and structural modifications were selected for sorption experiments with Co2+, Ni2+, Zn2+, Cd2+, Pb2+, and arsenate. It was intended to demonstrate the potential of mineral modification for improving sorption properties.Methods   Batch sorption studies were carried out combining each mineral with a single element at different pH and reaction times. Cations were investigated at a single initial concentration only while arsenate was tested over a range of concentrations in order to establish sorption isotherms. The sorption step was followed by an extraction step to characterize time dependent immobilization reactions.Results and Discussion   A time dependent increase of trace metal and arsenate sorption is attributed to a migration of ions into pores of star-shaped goethite and to a binding by specific sorption sites at the surface. The migration into pores is related to the size of adsorbing cations. The almost identical sorption behaviour of Ni2+ and Co2+ on pure goethite is contrasted by a strong preference of Co over Ni on Cd-goethite. Expansion of the unit-cell dimensions in Cd+2 substituted goethite generates highly specific binding sites at the surface. These are accessible to Co and Zn only. A permanent positive charge in Pb+4 substituted goethite reduces the binding of cations and doubles the sorption capacity for arsenate. Pb-goethite also contains a limited portion of highly specific sites which can only be accessed by Zn2+. Immobilization takes place even after a short contact time of 16 hours. This process results in a growing fraction of non-extractable metals and arsenate with reaction time.Conclusions   Pores and foreign elements in the goethite structure greatly affect the reactivity of the mineral and the ability to immobilize inorganic pollutants. A possible mechanisms for the preferred sorption of Co and Zn by Cd-goethite is seen in the ability of these metal ions to adopt a smaller size: Co by oxidation of Co2+ to Co3+ and Zn by tetrahedral coordination of Zn2+. This kind of binding can be viewed as structural incorporation. The binding properties of modified goethites can well be characterized by sorption tests including an array of elements with different ionic size and charge.Recommendation and Outlook   There is considerable potential for designing goethite modifications with improved surface reactivity for specific purposes such as water purification and possibly catalysis of reactions.     

Modeling ferricyanide adsorption on goethite: Basics and applications

Ferricyanide, [Fe^III(CN)₆]^3–, is an anthropogenic and potentially toxic contaminant in soil. Its adsorption on goethite has been previously studied, but not evaluated with a surface complexation model (SCM) considering the effects of pH and ionic strength. Therefore, we carried out batch experiments with ferricyanide and goethite suspensions with different ferricyanide concentrations (0.075 mM and 0.15 mM), ionic strengths (0.01 and 0.1 M), and pH (ranging from 4 to 7.4). Adsorption data were then interpreted with the 1‐pK Stern and the charge distribution model assuming monodentate inner‐sphere ferricyanide surface complexes on goethite (lg K = 10.6), which are known from infrared spectroscopy. Furthermore, we applied the SCM to ferricyanide adsorption in previous studies on ferricyanide adsorption in the presence of sulfate and on the solubility of Fe‐cyanide complexes in a suspension of a loess loam. The SCM correctly reflected ferricyanide adsorption in the batch experiments as well as the effects of pH and ionic strength. The SCM also described ferricyanide adsorption in the presence of sulfate, because the ferricyanide adsorption measured and that modeled were significantly correlated (R² = 0.80). Furthermore, we applied the SCM to a study on the solubility of Fe‐cyanide complexes in soil under varying redox conditions so that ferricyanide adsorption on goethite and precipitation of Fe‐cyanide complexes were considered. The actual ferricyanide concentrations were rather reflected when applying the SCM compared to those modeled in an approach in which exclusively precipitation was taken into account. We conclude that ferricyanide adsorption on goethite should be included into geochemical modeling approaches on the mobility of Fe‐cyanide complexes in subsoils.     

pH对针铁矿表面磷酸盐吸附的化学形态的影响

Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinate groups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results showed that the chemical forms of P on goethite surfaces changed from the dominance of monodentate corrdination to that of bidentate one with increasing pH of the solution.By influencing types of phosphate ions in solutions,pH affected the chemical forms of P on goethite surfaces,The amount of OH^- displaced by phosphae on goethite surfaces was the most at pH 7.0,the second at pH 9.0,and the least at pH 4.5.     

Sorption of iron‐cyanide complexes on goethite investigated in long‐term experiments

The iron‐cyanide complexes ferrocyanide, [Fe^II(CN)₆]^4–, and ferricyanide, [Fe^III(CN)₆]^3–, are anthropogenic contaminants in soil. We investigated their sorption on goethite, α‐FeOOH, in batch experiments in a time range from 1 d to 1 yr, their desorption by phosphate and chloride as well as their surface complexes on goethite by Fourier‐transform infrared spectroscopy (FTIR). The sorption of both complexes continued over the whole time range. Percent desorption of ferricyanide by phosphate decreased, whereas that of ferrocyanide increased until it amounted to approximately 87% for both complexes. By FTIR spectroscopy inner‐sphere complexation of both complexes on the goethite surface was indicated. With both complexes, a Berlin‐Blue‐like layer (Fe₄[Fe(CN)₆]₃) was formed initially on the goethite surface which disappeared with increasing reaction time. After at least 30 d reaction time, ferricyanide was the only sorbed iron‐cyanide complex detected even when ferrocyanide was initially added. This resulted from slow oxidation of ferrocyanide, most probably by dissolved oxygen. Based on all results, we propose that ferricyanide forms monodentate inner‐sphere complexes on the goethite surface.     

作物秸秆与城市污泥高温好氧堆肥产物对土壤氮矿化的影响

为揭示不同作物秸秆与污泥堆肥产物对土壤氮素矿化特征的影响,为科学施用城市污泥堆肥提供参考依据,通过室内培养试验研究了城市污泥与4种秸秆（小麦、水稻、玉米和油菜）高温好氧堆肥产物施入酸性紫色土、黄壤、石灰性紫色土后土壤氮矿化的差异。结果表明,4秸秆污泥堆肥均可显著提高3种土壤氮的潜在矿化势（N0）和矿化速度（k）,促进土壤氮的矿化,提高土壤NH4+-N、NO3--N质量分数,其中石灰性紫色土以油菜秸秆污泥堆肥和小麦秸秆污泥堆肥处理、黄壤以油菜秸秆污泥堆肥处理、酸性紫色土以小麦秸秆污泥堆肥处理提高幅度最大。作物秸秆与污泥堆肥施入土壤后,黄壤、酸性紫色土在培养60 d和30 d后趋于稳定,石灰性紫色土在培养60 d后仍有增高的趋势,但不同秸秆污泥堆肥对土壤氮矿化速度的影响无明显规律。结果说明秸秆污泥堆肥对土壤氮矿化的效应因土壤及秸秆类型的不同而异,根据研究结果提出了4种作物秸秆与城市污泥堆肥施用的建议。     

Mineralogical composition of iron oxides in red- and yellow-colored soils from Southern Japan and Yunnan,China

Six soil samples from the Bt2 horizon of red- and yellow-colored soils collected in Southern Japan and Yunnan, China, were used in this study. Detailed mineralogical studies by differential X-ray diffraction analysis showed the presence of hematite in association with goethite in the red-colored soils, whereas no hematite was detected in the yellow-colored soils. Among the samples studied, the increase in the hematite contents was as follows: Terra rossa-like/Red-Yellow soil in Kikai Island, Red soil in Toyota City, Lateritic Red soil in Minami-Daito Island and Lateritic Red soil in Yunnan, China. Since Lateritic Red soil and Lateritic Yellow soil are distributed adjacently on the Pleistocene raised coral reef terrace in Minami-Daito Island, having a fairly similar soil temperature regime, soil pH, soil organic matter and iron oxide contents, the difference in the soil color between the two soils may be caused by the difference in the hydrologic conditions.     

不同调理剂对酸性土壤降酸效果及大麦幼苗生长的影响

采用土壤培养及盆栽试验研究5种调理剂(生石灰、油菜秸秆、有机肥、钾硅肥、土壤改良剂,用量均为1.8 g/kg)对酸性土壤(pH值3.9)酸度指标和大麦幼苗生长的影响。土壤培养试验结果表明,施用生石灰、有机肥和钾硅肥均能明显提高土壤pH值,降低土壤交换性酸总量、交换性H+和交换性铝含量。其中以生石灰降酸效果最好,到培养第90 d,相比于对照处理提高了0.66个单位,土壤交换性铝含量减少了2.01 cmol/kg;其次是有机肥和钾硅肥处理,pH值较对照处理分别提高了0.14和0.15,土壤交换性铝含量分别降低了0.23和0.19cmol/kg;油菜秸秆和土壤改良剂处理从酸度指标来看,与对照并没有显著差异。大麦幼苗盆栽试验结果表明,与对照相比,生石灰、油菜秸秆、有机肥、钾硅肥和土壤改良剂处理的大麦幼苗地上部生物量分别增加71.5%、24.1%、27.6%、28.2%、24.7%,大麦株高、根长、根系总表面积和根系活力均显著高于对照处理,根系平均直径减少,有利于养分和水分的吸收。综合结果表明,不同类型的调理剂对酸性土壤的降酸效果不尽相同,其中以生石灰效果最好,秸秆处理尽管没有有效降低土壤酸度但仍可明显促进作物生长,因此也可用作酸性土壤的改良物质,在实际生产中应因地制宜应用各种调节物质来促进作物生长。     

根际施肥调控对油菜硝酸盐含量的影响研究

利用盆栽试验,测定了肥料周围不同距离处土壤中NH4+与NO3-增量的变化,验证不同施肥方式对小油菜产量与NO3-含量的影响。结果发现,通过肥料在土壤中的扩散作用,肥料氮对土壤NH4+与NO3-增量的影响范围主要是在距肥料4cm内,但集中施肥与酸性根际肥(Ph1.0～2.0)的显著差异则是在2cm内;后者的NH4+扩散与硝化作用都较前者弱。其中,在距肥料1cm处,集中施肥的土壤NH4+增量于施肥一周后达最大值,而酸性根际肥则在两周后,且两者NH4+增量差异显著;在2cm处,二者土壤NH4+增量达最大值的时间都较1cm处晚一周,且前者显著低于后者,而后者土壤的NO3-增量都低于前者。在盆栽试验中,酸性根际肥使小油菜的土壤NH4+含量显著提高,而NO3-含量却很低。与集中施肥比较,土壤NH4+含量提高13%,NO3-含量降低72%～89%,小油菜的硝酸盐累积量降低了28%,小油菜产量增加39%。     

添加生物质炭对黄棕壤和红壤上油菜生长的影响

通过盆栽试验,探究施用不同比例的生物质炭对黄棕壤和红壤理化性质和油菜生长发育的影响。结果表明:黄棕壤和红壤在添加1%生物质炭后,两者的pH值、有效磷、速效钾、有机质含量均比对照显著增加。油菜根、茎、叶、角果、籽粒等干物重均增加,其中黄棕壤上油菜籽粒产量比对照提高114.8%,达到显著水平。添加生物质炭后,两种土壤上油菜各部位氮含量均有所下降,磷含量也呈降低趋势,钾含量则有所升高,其中红壤上油菜的变化幅度较黄棕壤显著。由于油菜干物重增加,两种土壤上油菜氮磷钾积累量在加入生物质炭后也有明显地提高。因此,施用1%生物质炭可以促进油菜生长,并有助于油菜对磷、钾等养分的吸收。     

pH变化条件下针铁矿表面吸附的磷酸盐联合态的转化

X-ray photoelectron spectroscopy(XPS) and automatic titrimeter were used to study the relation bewteen pH and the transformation of the coordinate forms of P on goethite surfaces.The results showed that for a given P concentration,increasing the pH of suspension could cause a fast transformation of monodentate complexes of phosphate ions on goethite surfaces to binuclear ones,When lowering the pH,additional adsorption of P occurred and the binuclear complexes reverted slowly to the monodentate ones,The dissociation and association of protons of the sorbed P caused by pH changes was considered to be a major reason leading to the transformation of the coordinate forms of P on the surfaces.The stability of binuclear surface complex of P was greater than that of monodentate omplex.The possible reactions on the interface of goethite and solutions with pH changes,and the reasons causing the different stabilities of the two coordinate P complexes are discussed in the paper.     

不同氧化物硼负载体吸附锰离子的特性研究

以人工合成针铁矿（Goethite，简写为G），水锰矿（Manganite，简写为M），经硼砂处理的吸附态针铁矿（简写为Ad—B-G），吸附态水锰矿（简写为Ad—B-M），经硼酸处理的包被态针铁矿（简写为Oc—B—G），包被态水锰矿（简写为Oc-B—M）等6种氧化物为研究对象，在等温条件下，用吸附平衡法研究了6种硼负载体对Mn^2＋的吸附解吸行为。结果表明，吸附Mn^2＋能力：Oc—B—G〉Ad—B—G〉G；Ad—B—M和Oc—B—M吸附Mn^2＋量最大，M吸附能力最弱。6种硼负载体Mn^2＋吸附量随pH升高而增加,但铁氧化物和锰氧化物之间有差别。不同形态锰氧化物吸附Mn^2＋前后溶液pH变化不同，吸附等量Mn^2＋离子时，Ad—B—M向溶液中释放H^＋量最多，Oc—B—M最少。上述结果说明，硼的参与不仅可改变氧化物吸附Mn^2＋离子的行为，而且对反应体系的影响也不尽相同。     

缓释型保水剂对土壤物理性状作用及油菜增产效果的研究

田间小区试验对施用缓释型保水剂、保水剂、常规肥料下土壤物理性状及油菜生长进行了研究。结果表明,缓释型保水剂为植株提供适宜的水分条件,促进了作物生长,油菜产量增加;缓释型保水剂具有保水和持水性能,提高了土壤水分含量,同时改善了土壤物理性状,降低土壤容重,使土壤孔隙数量增加,提高了土壤总孔隙度,尤其增加了非毛管孔隙度,增强了土壤通气性能;缓释型保水剂增加了土壤中大于0.25mm团聚体的数量,从而提高了土壤通气性,同时也增加了土壤中2mm以上的团聚体数量,提高了土壤的抗蚀性。