Cuticular penetration of calcium salts: effects of humidity,anions, and adjuvants

Physical laws of cuticular penetration of calcium salts have been studied using astomatous isolated pear (Pyrus communis L.) leaf cuticular membranes (CM). Penetration followed first order kinetics and was greatly affected by humidity, hygroscopicity, solubility of salts, and nature of adjuvants. Penetration required dissolution of the salts and this is determined by their point of deliquescence (POD). POD corresponds to the humidity over a saturated salt solution containing undissolved salt. When humidity was above POD the salt residue on the cuticle dissolved, while below a solid residue was formed and penetration ceased. CaCl₂ and Ca(NO₃)₂ have POD's of 32 and 55%, respectively, while POD's of organic calcium salts (acetate, lactate, propionate) were between 95 and 100%. Furthermore, aqueous solubility of the inorganic calcium salts is one to two orders of magnitude higher than that of the organic salts. Thus, organic calcium salts are not well suited for foliar nutrition since POD's are very high and driving forces of penetration are low due to low solubility even at 100% humidity. CaCl₂ and Ca(NO₃)₂ penetrate even at low humidity and solubility is much higher. When humidity was above the POD, rate constants of penetration increased with increasing humidity by about a factor of three and maximum rates were measured at 100%. Temperature did not affect rate constants of penetration from which it can be concluded that penetration is most rapid during the night when humidity is high. All salts should be used with an effective wetter as with an alkyl polyglucoside half time of penetration was decreased from 204 to 17 h. All other adjuvants tested (protein hydrolysates, EDTA, gum guar) decreased rate constants of penetration by factors of 3 to 9. This finding is discussed in relation to mixing foliar nutrients with fungizides.     

Rates of cuticular penetration of chelated Fe(III): role of humidity, concentration, adjuvants, temperature, and type of chelate

Time courses of cuticular penetration of FeCl3 and Fe(III) complexes of citric acid, EDTA, EDDHA (Sequestrene 138Fe), imidodisuccinic acid (IDHA), and ligninsulfonic acid (Natrel) were studied using astomatous cuticular membranes (CMs) isolated from Populus x canescens leaves. At 100% relative humidity, the Fe(III) chelates disappeared exponentially with time from the surface of the CMs; that is, penetration was a first-order process that can be described using rate constants or half-times of penetration (t(1/2)). Half-times ranged from 20 to 30 h. At 90% humidity, penetration rates were insignificant with the exception of Natrel, for which t(1/2) amounted to 58 h. Rate constants were independent of temperature (15, 25, and 35 degrees C). Permeability decreased with increasing Fe chelate concentration (IDHA and EDTA). At 100% humidity, half-times measured with FeIDHA were 11 h (2 mmol L(-1)), 17 h (10 mmol L(-1)) and 36 h (20 mmol L(-1)), respectively. In the presence of FeEDTA, penetration of CaCl2 was slowed greatly. Half-times for penetration of CaCl2, which were 1.9 h in the absence of FeEDTA, rose to 3.12 h in the presence of an equimolar concentration of EDTA and 13.3 h when the FeEDTA concentration was doubled. Hence, Fe chelates reduced permeability of CMs to CaCl2 and to the Fe chelates themselves. It is suggested that Fe chelates reduced the size of aqueous pores. This view is supported by the fact that rate constants for calcium salts were about 5 times higher than for Fe chelates with the same molecular weights. Adding Tween 20 (5 g L(-1)) as a humectant did not increase permeability to FeIDHA at 90% humidity and below, while addition of glycine betaine did. Penetration of FeCl3 applied at 5 g L(-1) (pH 1.5) was not a first order process as rate constants decreased rapidly with time. Only 2% of the dose penetrated during the first 2 h and less than that in the subsequent 8 h. Recovery was only 70%. This was attributed to the formation of insoluble Fe hydroxide precipitates on CMs. These results explain why in the past foliar application of Fe compounds had limited success. Inorganic Fe salts are instable and phytotoxic because of low pH, while Fe chelates penetrate slowly and 100% humidity is required for significant penetration rates. Concentrations as low as reasonably possible should be used. These physical facts are expected to apply to stomatous leaf surfaces as well, but absolute rates probably depend on leaf age and plant species. High humidity in stagnant air layers may favor penetration rates across stomatous leaf surfaces when humidity in bulk air is below 100%.     

Mixing calcium chloride with commercial fungicide formulations results in very slow penetration of calcium into apple fruits

Foliar applications of calcium salts are usually combined with fungicides. In the years 2002 and 2003, it was tested if this practice assures high rates of penetration of calcium. Amounts that penetrated in 24 h were measured at 20 °C using ⁴⁵CaCl₂. To ensure maximum penetration rates, humidity was maintained at 100 %. Sample size was 40 to 50 fruits, and data were presented as box plots because distribution of data was not normal. Median rates of penetration of CaCl₂, measured with mixtures of fungicides and CaCl₂ at 5 or 10 g l^–1, respectively, were very slow, and amounted to only a few percent of the dose applied. Rates were a little higher with very young fruits (55 days after full bloom, DAFB). Adding alkyl polyglycoside surfactants at 0.2 g l^–1 significantly decreased surface tensions, and increased rates of penetration by up to 15‐fold. Still, total penetration of CaCl₂ rarely exceeded 20 % of the dose applied (median penetration), even in the presence of an additional surfactant. In all treatments, outliers with 60 to 100 % penetration in 24 h occurred, and this was attributed to penetration into lenticels. This is expected to result in unequal concentrations of calcium in fruits, especially in the sub‐epidermal layers. Addition of a suitable surfactant to mixtures of fungicides with CaCl₂ is strongly recommended as it enhances wetting and greatly increases penetration rates of CaCl₂.     

化肥减量配施黄腐酸降低盐渍农田NaCl含量提高氮磷养分有效性的协同效应

[目的]土壤盐渍化以及肥料过量施用严重限制着黄河三角洲盐渍化地区农业的可持续发展.综合分析氮、磷肥优化减量及其与黄腐酸配施对盐渍农田土壤肥力、冬小麦产量以及养分吸收利用的影响,可为该区盐渍农田化肥减施增效提供理论依据.[方法]以黄河三角洲中度盐土[pH 7.73、电导率 (EC) 1.18 dS/m]为研究对象进行室内...     

山梨醇螯合钙对NaCl胁迫下油菜种子萌发的影响

本文通过控制钙源种类(螯合态钙和游离态钙)、两种形态钙配比(不同螯合率)及螯合态钙浓度等3组试验探究山梨醇螯合钙对NaCl胁迫下油菜种子萌发的影响.结果表明:当培养液中NaCl浓度为150或170 mmol/L时严重影响油菜种子的萌发和胚根生长,添加两种形态钙后均能显著提高NaCl胁迫下种子活力和发芽率,促进胚根的生长...     

Selected Calcium Salt Formulations: Interactions between Spray Deposit Characteristics and Ca Penetration with Consequences for Rain-Induced Wash-Off

The effect of two ethoxylated rapeseed oils (RSO) as surfactants for foliar-applied calcium chloride CaCl₂ and calcium acetate Ca(CH₃COO)₂ on deposit characteristics, penetration, and calcium (Ca) residues after rainfall was investigated in columnar apple trees (CAT, Malus domestica Borkh.) and apple seedlings. Irrespective of salt and apple variety, both surfactants enhanced droplet spreading and led to a greater area covered by calcium within the droplet residues. The addition of the rather lipophilic surfactant RSO 5 and the rather hydrophilic RSO 60 increased penetration of Ca from both salts through isolated apple leaf cuticular membranes. Our data demonstrate that penetration is better reflected by area covered with calcium than by droplet spreading area. Considering the point of deliquescence (POD) from the salts and results of cuticular Ca penetration, we postulate that in case of CaCl₂ reduction of wash-off was due to enhanced penetration, whereas for Ca(CH₃COO)₂ wash-off was decreased due to distinct enhancement of rainfastness.     

不同氮形态配比对菠菜营养品质及抗氧化酶活性的影响

通过水培试验研究了不同氮形态配比对菠菜可食部位硝酸盐、草酸、维C含量及POD、CAT、SOD抗氧化酶活性的影响。结果表明:随铵态氮比例的增加,菠菜可食部位的硝酸盐、草酸含量逐渐减少,在完全供铵时含量最少。硝态氮/铵态氮比为25/75时Vc含量最高。在增加铵态氮比例时,POD、SOD和CAT活性有所下降,而在完全供铵时,P0D、S0D、CAT活性最高,MDA含量也最高。     

Biodegradation of oxalic acid from spinach using cereal radicles

A high level of oxalate intake constitutes a health risk for infants and metabolically disposed adults. Spinach, acclaimed for its many health benefits, is among the vegetables richest in oxalate. Blanching reduces oxalate unsatisfactorily and unspecifically. An alternative, biological method is proposed on the basis of rye seedlings or radicles (also barley and wheat) containing an oxalate-specific oxalate oxidase by nature. Dissolved oxalate (0.25 mM) was rapidly degraded in the presence of radicles (e.g., 70% within 100 min). With commercial deep-frozen spinach, near-complete degradation of soluble oxalate was achieved at pH 3.5. The total level of oxalate was reduced by half. Similarly high rates occurred from 18 to 35 degrees C. Even at 55 degrees C appreciable rates were observed. The seedling as a whole is effective, too, and enrichment with cereal-specific healthy components would occur. Removal of oxalate from other vegetables, juices, cycled process waters, or feeds is conceivable with fresh or heat-dried cereal seedlings or radicles.     

硝/铵营养对香蕉生长及其枯萎病发生的影响

通过水培试验,研究了不同硝/铵配比对香蕉生长及其根际尖孢镰刀菌侵染的影响。结果表明, 1）铵硝混合营养对香蕉生长的效果优于单一营养,尤其是在75%硝态氮+25%铵态氮处理下香蕉生长最好,叶片中氮、磷、钾含量也最高; 2）香蕉根际pH在100%铵态氮处理时最低,随着硝态氮比例的增加,pH逐渐上升; 3）接种尖孢镰刀菌后,根际病原菌数量在100% 铵态氮处理时最多,但是在根系细胞内却没有检测到,相反,随着硝态氮比例的增加,虽然在根际中检测到的病菌数量有所降低,但是在根系内均发现存在病原菌。本研究结果说明,相对于铵硝混合营养,全铵营养会导致香蕉生长受到一定的影响,但是却能够防止香蕉尖孢镰刀菌侵染进植物根系。由于在离体培养时,全铵可以抑制尖孢镰刀菌穿透植物细胞壁的过程,因此全铵培养植物时,其根部质外体及细胞中铵态氮浓度高很可能是抑制病原菌侵染的主要原因。     

Reactions of chrome tannery sludge with organic and mineral soils

Chrome tannery sludge applied to agricultural land may have benefits in terms of added N for crop growth. An experiment was designed to compare tannery waste with commercial N fertilizer and investigate the potential of the waste as an alternative or supplement to commercial fertilizer. Soils with 38% and 7% organic C and N content of 1.3% and 0.2%, respectively, were amended with lime, commercial N fertilizer, or tannery sludge containing 1.6% Cr. A portion of the tannery waste was supplemented with additional Cr 3⁺ salt before adding to the soils. The amended soils were analyzed for total Cr, ammonium acetate extractable Cr, selected nutrient and trace element concentrations. The tannery sludge increased soil pH, total Cr and N, S, Ca, P, Mg, and Na concentrations. DTPA extractable Cr increased only when Cr³⁺ salt was added, but soil pH decreased markedly. Electroconductivity of the soils increased with the waste application rate and, at the highest rate of Cr³⁺ salt addition, far exceeded values recommended for successful crop production. The acidic, high salt conditions complicated interpretation of the Cr³⁺ salt addition results. Tannery sludge may be applied to agricultural land as a fertilizer amendment without adversely affecting soil chemical properties. The amount and frequency of application should be determined by (1) total and available N, (2) total salt content, (3) total and available Cr, and (4) soil organic matter.     

Inhibiting effects of resveratrol and its glucoside piceid against Venturia inaequalis, the causal agent of apple scab

Resveratrol is a phytoalexin produced in different unrelated plant species such as grapevine and peanut. The effect of resveratrol and its glucoside trans-resveratrol-3-O-beta-D-glycopyranosid (piceid) against Venturia inaequalis, the causal agent of apple scab, was evaluated using a newly established test based on enzymatically isolated cuticular membranes (CMs) from apple (Malus domestica Borkh.) leaves. The test substances resveratrol and piceid were either sorbed to CMs before inoculation with spores or were applied simultaneously with the Venturia inaequalis spores to the CMs, and their effect on germination, appressoria formation, and penetration was examined. Resveratrol had no influence on spore germination but a significant inhibiting effect on penetration when applied simultaneously as well as before. A percentage inhibition of 89.7 +/- 11.5 and 61.8 +/- 35.1 was observed for simultaneous and preapplication, respectively. The resveratrol glucoside piceid had a significant inhibitory effect on germination and completely inhibited penetration of the fungus at concentrations between 200 and 400 microg mL(-1) when applied simultaneously with the spores to the CMs. On piceid-enriched CM (preapplication), spores germinated but penetration was inhibited nearly completely (96.1 +/- 5.1%). Thus, in vitro experiments showed that resveratrol and its glucoside in fact could contribute to improving the pathogen resistance of apple leaves.     

Optimum conditions for extraction of Al,Fe, and Si from soils with acid oxalate

Abstract

Acid oxalate reagent was used at various concentrations, pH values, shaking times, and soil to solution ratios to find the optimum conditions for the extraction of Al, Fe, and Si from short‐range‐order materials in soils and stream‐bed deposits. The optimum conditions vary with the nature of the soil sample and its components. For most soils maximum amounts of Al, Fe, and Si were extracted with 0.15M acid oxalate reagent at pH 3.0 with a soil to solution ratio of 1:100 and shaking for 4 h in the dark at 20°C. Soils with more than 5% oxalate‐extractable Al or Fe require a 0.20M oxalate solution at pH 3.0 with a soil to solution ratio of 1:200.

Allophane is extracted by acid oxalate reagent after shaking for 2 h and it may be estimated from the 4 h oxalate‐extractable Si values. Ferrihydrite is extracted after shaking for 4 h, and it may be estimated from the oxalate‐extractable Fe values. Either sodium oxalate or ammonium oxalate may be used     

Rates of foliar penetration of chelated Fe(III): role of light, stomata, species, and leaf age

Rates of foliar penetration of Fe(III) chelates of imidodisuccinic acid (IDHA), ligninsulfonic acid (Natrel), and citric acid (ammonium ferric citrate) were studied at 20 degrees C using a leaf disk method. After drying of the donor droplets, the humidity over the donor residues was maintained at 100% because Fe(III) chelates deliquesce only when humidity is higher than 90%. The wetting agent Glucopon 215 CSUP was added at a concentration of 0.2 g L(-1) to all donor solutions. With fully expanded stomatous broad bean leaves, penetration of Fe-IDHA followed first-order kinetics and rate constants of penetration were higher in light (0.073 h(-1)) than in the dark (0.042 h(-1)). Permeability of broad been leaves to CaCl2 was about 8 times higher than to Fe-IDHA. Doubling the Fe-IDHA concentration in the donor from 2.5 to 5 mmol L(-1) decreased rate constants of Fe-IDHA penetration by a factor of 2.2. Adding the silicon surfactant Break Thru S240 at 10 g L(-1) to the donor induced infiltration of open stomata and about 80% of the applied Fe-IDHA penetrated during droplet drying, while with Glucopon 215 CSUP stomatal infiltration was not observed. With broad bean leaves, penetration of Natrel and ammonium ferric citrate also followed first-order kinetics and rate constants were also higher in light than in the dark. Adaxial astomatous surfaces of fully expanded pear, apple, and grapevine leaves were practically impermeable to Fe-IDHA while stomatous abaxial leaf surfaces were permeable, but rate constants of penetration decreased with time and differed greatly among species. Astomatous surfaces of young unfurling grapevine and peach leaves were permeable to Fe-IDHA, but permeability of stomatous surfaces was much higher. The effect of light on permeability of stomatous leaf surfaces is attributed to the presence of aqueous pores in cuticles over guard cells, and it is suggested that permeability of these pores increases as stomata open. Consequences of these results for foliar applications of Fe chelates are discussed.     

不同种植密度下温室间作玉米的水分利用情况与其营养元素吸收特征的关系

Dent corn, as a catch crop used for salt removal, was cultivated at different densities, i.e., 7.3 （low density）, 59.7 （normal density）, and 119.5 plants m-2 （high density）, during a 50 d fallow period after cultivation of a commercial crop in a greenhouse, to analyze the characteristics of nutrient salt （N, K, Mg, and Ca） uptake by roots and to study the effect of plant density on the characteristics associated with crop water use. Leaf area index for the high and normal density treatments reached extremely high values of 24.3 and 14.9, respectively. These values induced higher transpiration rates that were estimated using the Penman-Monteith model with the incorporation of specific parameters for crop and greenhouse conditions. The total N, K, Mg, and Ca contents in the crop canopy at harvest were 26.8, 13.0, 1.0, and 1.7 g m-S, respectively, under the high density treatment. The dynamics of salt uptake rates for high, normal, and low density treatments were evaluated by assessing weekly changes in salt content, and were subsequently compared against the transpiration rate. A positive linear relationship was obtained between these 2 parameters for all 3 density treatments and all tested salts. Hence, higher transpiration rates caused higher salt uptake rates through water absorption. On the other hand, salt uptake efficiency per unit water use by cultivation was lower in the low density treatment. Therefore, management procedures with dense planting that induce higher transpiration rates and lower evaporation rate are extremely important for the effective cultivation of corn catch crops.     

Effect of certain herbicides on soil microbial populations and their influence on saprophytic growth in soil and pathogenicity of take-all fungus

Summary The application of diquat + paraquat, glyphosate and trifluralin to unsterilized field soil increased take-all caused by the fungus, Gaeumannomyces graminis var. tritici Walker by 13.0% 16.6% and 10.8% respectively, while no effect on disease was recorded in sterilized soil treated with the same herbicides. The herbicides tested had no effect on the saprophytic growth of the pathogen with the exception of glyphosate, which increased its growth in unsterilized soil. The application of diquat + paraquat and glyphosate to unsterile soil had no effect on the numbers of actinomycetes. The diquat + paraquat treatment, however, increased populations of fungi while the glyphosate decreased the numbers of bacteria. The proportion of soil fungi antagonistic to the pathogen was reduced in glyphosate-treated soil. The frequency of occurrence of Eupenicillium euglaucum (v. Beyma) Stolk & Samson (strain B), and Penicillium verruculosum Peyr. (strain B), which were strong and low level antagonists of Ggt on agar, were reduced in their occurrence in soil by 7.7% and 2.5% respectively, following glyphosate treatment. Moreover, the numbers of Aspergillus viridinutans Ducker & Thrower, which showed moderate antagonism to the pathogen, was decreased by 1.9% and 4.1% in diquat + paraquat and glyphosate treatments respectively. The proportion of antagonists rather than total numbers of fungi appears to be related to the treatment effect observed on the soil growth and pathogenicity of G. graminis var. tritici in our investigation. The increase in disease of wheat in certain herbicide-treated soils may be due to the shift in soil microbial populations away from those which are antagonistic to the pathogen.     

Influence of Urea and Ammonium Sulfate on Soil Acidity Indices in Lowland Rice Production

Urea and ammonium sulfate are principal nitrogen (N) sources for crop production. Two field experiments were conducted during three consecutive years to evaluate influence of urea and ammonium sulfate application on grain yield, soil pH, calcium (Ca) saturation, magnesium (Mg) saturation, base saturation, aluminum (Al) saturation, and acidity (H + Al) saturation in lowland rice production. Grain yield was significantly influenced by urea as well as ammonium sulfate fertilization. Soil pH linearly decreased with the application of N by ammonium sulfate and urea fertilizers. However, the magnitude of the pH decrease was greater by ammonium sulfate than by urea. The Ca and Mg saturations were decreased at the greater N rates compared to low rates of N by both the fertilizer sources. The Al and acidity saturation increased with increasing N rates by both the fertilizer sources. However, these acidity indices were increased more with the application of ammonium sulfate compared with urea. Rice grain yield had negative associations with pH, Ca saturation, Mg saturation, and base saturation and positive associations with Al and acidity saturation. This indicates that rice plant is tolerant to soil acidity.     

Effect of certain herbicides on growth and pathogenicity of take-all fungus on wheat (Triticum aestivum L.)

Summary The effects of Spray Seed (diquat + paraquat), Roundup (glyphosate), Banvel-D (dicamba), Treflan (trifluralin), Glean (chlorsulfuron) and Dacthal (chlorthal dimethyl) at concentrations of 0–500 ppm product on the vegetative growth, vigour and pathogenicity of Gaeumannomyces graminis var. tritici (Ggt) on wheat were examined. All herbicides with the exception of dicamba and chlorsulfuron inhibited fungal growth on potato dextrose agar (PDA) at concentrations 10–500-fold of rates recommended for use in the field. The vegetative growth of the pathogen growing out of straw colonized on PDA supplemented with 100 ppm diquat + paraquat or glyphosate was reduced by 47.4% and 42.4%, respectively. When portions of these colonies were subcultured onto unamended PDA, their growth and the pathogenicity of straw pieces colonized by these subcultures were found to be unaltered. Straw colonized by Ggt on agar amended with concentrations of diquat + paraquat or at all concentrations of glyphosate produced less root disease in wheat seedlings in comparison to those colonized on unamended agar. It is proposed that the reduced pathogenicity of inocula prepared on agar amended with these two herbicides is due to poor colonization by the pathogen of straw on these media, and that a similar effect on saprophytic colonization in the field could lead to a reduction in the field inocula of the pathogen.     

适宜无机盐及浓度抑制麦胚脂肪酶存在时油水界面张力

为了探明无机盐稳定化脂肪酶的潜在机理,该文以小麦胚芽脂肪酶为研究对象,基于界面酶学的分析方法,研究添加浓度介于1.0×10-9~1.0×10-2 mol/L的Na~+、K+、Ca~(2+)、Mg~(2+)的氯化物对小麦胚芽脂肪酶存在的油-水界面特性的影响。结果表明,当小麦胚芽脂肪酶体系浓度为1.7×10-6 mol/L时,一价金属中Na~+更有利于抑制油-水界面的表面张力(P0.05),对麦胚脂肪酶存在时的油水界面特性影响也较大;二价金属离子Ca~(2+)对界面张力的影响趋势与一价离子不同,在高浓度时反而增加界面张力;当油水界面上存在脂肪酶的催化底物(三油酸甘油酯)和产物(油酸)时,添加浓度分别为10-6、10-6、10-4和10-9mol/L的Na~+、K~+、Ca~(2+)、Mg~(2+)均可一定程度上降低油水界面张力,从而降低麦胚脂肪酶的作用效果,三油酸甘油酯存在时Mg~(2+)的作用效果最明显(P0.05),油酸存在时Na+的作用效果最明显(P0.05)。综上,无机盐金属离子主要通过影响麦胚脂肪酶在油水界面的聚集行为及底物结构状态起到钝化麦胚脂肪酶的作用,该结果可为麦胚脂肪酶存在时界面的活性调控及麦胚的稳定化处理提供参考。     

Influence of incubation temperature on the behavior of triethylamine-extractable glyphosate (N-phosphonomethylglycine) in four soils

The behavior of glyphosate, extracted from four soils using aqueous triethylamine, was investigated at two temperatures. For each soil, and at both temperatures, there was a marked loss in the amount of extractable glyphosate immediately after addition of the herbicide to soil. This rapid loss of glyphosate was ascribed to adsorption of the herbicide into a nonextractable form. For three of the four soils used when incubated at 25 degrees C, the rates of loss of extractable glyphosate were similar to previously measured rates of degradation of this herbicide in these soils. However, loss of extractable glyphosate from the Culgoa clay loam was due not only to substrate degradation but also to slow sorption of glyphosate into the nonextractable form in this soil over the experimental period. For the Rutherglen and Walpeup soils, when incubated at 10 degrees C, the rates of loss of extractable glyphosate were half of the previously measured rate of degradation of this herbicide in these soils. However, there was no measured loss of extractable glyphosate from the Wimmera clay. As previous work has shown glyphosate to decompose readily in these soils at this temperature, these findings suggest that desorption of glyphosate may occur at a rate greater than degradation at this temperature and, hence, that temperature may play a pivotal role in sorption processes. Investigations with these soils when sterilized by gamma-irradiation showed that for the Walpeup, Wimmera, and Rutherglen soils, sorption was complete soon after the addition of the herbicide; however, for the Culgoa soil, further adsorption occurred over the entire experimental period.     

氮肥施用对砖红壤硝态氮和盐基离子淋失特征的影响

氮肥品种的合理选用对作物增产增收、 土壤酸化改良有重要的影响。本文以海南省海口市观澜湖采集的砖红壤为研究对象,采用室内土柱模拟试验,对尿素、 硝酸铵和硫酸铵3种氮肥处理下砖红壤硝态氮及盐基离子（Ca2+、 Mg2+、 K+、 Na+）淋失特征进行了研究。结果表明, 1）硝态氮累积淋溶量表现为硫酸铵硝酸铵尿素N0,且硝态氮的淋溶量与施肥量呈正相关关系,整个淋溶过程中硝态氮累积淋溶量（y kg/hm2）与施肥量（x kg/hm2）之间满足线性方程 y=3.3064x+315.74（R2=0.8848）; 2）尿素、 硝酸铵、 硫酸铵处理整个淋溶过程的盐基离子淋溶量均表现为 Ca2+Mg2+K+Na+,且盐基离子淋溶总量（kg/hm2）表现为硫酸铵（1821.12）硝酸铵（1080.27）尿素（872.24）N0（417.23）; 3）砖红壤盐基离子迁移速率表现为硫酸铵（26.28%）硝酸铵（13.37%）尿素（11.78%）,尿素、 硝酸铵和硫酸铵处理分别以线性方程 y=0.1178x+123.18（R2=0.9121）、 乘幂方程 y=15.634x0.4423（R2=0.9259）和对数方程 y=128.38e0.0007x（R2= 0.9244）的拟合度最高。