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Interaction of NpK Fertilizers During Their Transformation in soils: I. Dynamic Changes of soil pH

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pedosphere 2003年第3期13卷 257-262页

作者： WANG HUoYAN, ZHoU JIANMIN, chen XIAoQIN, LI SHoUTIAN, DU CHANGWEN and DoNG CAIXIAInstitute of soil science, the Chinese Academy of sciences, nanjing 210008 (China) Institute of soil science the Chinese Academy of Sciences Nanjing 210008

Dynamic changes of soil pH as influenced by ammonium sulfate (AS),monocalciuin phosphate (MCp), potassium chloride (KCl) and their interaction in soils were evaluatedin incubation experiments. Applying these fertilizers significantly reduced soil pH values in allcases and followed sequences of AS > MCp > KCl, MCp > KCl > AS and KCl > AS > MCp for the paddy,calcareous and red soils, respectively. The AS-induced reduction of pH in the three soils followedthe sequence of red soil > paddy soil > calcareous soil, while in MCp and KCl systems the reductionof pH followed the sequences of calcareous soil > paddy soil > red soil and red soil > calcareoussoil > paddy soil, respectively. The interactions of the NpK fertilizers on pH were significant. MCpplus KCl or MCp plus AS reduced pH values more than the fertilizers applied solely in the paddysoil, but AS partly counteracted the effect of MCp on pH in the 1 d sample of the calcareous *** effect of MCp on pH was trivial when MCp was applied in combination with KCl or AS in the redsoil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed thereduction of pH at the later incubation stage, which was related to inhibition of nitrification byKCl in the soils.

关键词： nitrogen pH phosphorus potassium

Kinetic Characteristics of Nitrate Uptake by Wheat and Rape and Their Determination

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pedosphere 1993年第2期3卷 127-132页

作者： ZHANGLI－GAN XUANJIA－XIANG 等 AnhuiAgriculturalCollege Hefei230036（China） Instituteofsoilscience AcademiaSinicaP.O.Box821Nanjing2

15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNo3 for a definite period of time. The changes in No3- concentration of the solutions were determined by the double ion-selective electrode method, and then the amount of No3- taken up by the plants was estimated and values of Km and Imax of the Michealis-Menten equation were calculated. Results show that both the method and conditions of determination affected the values of Km and Imax. For example, the Km value was appreciably reduced when the volume of culture solution was increased or when the duration of nutrient uptake was shortened; the Km value obtained with short-term depletion method was higher than that obtained with long-term one. Similar Variations were found for the values of Imax. There was a considerable difference in the characteristics of uptake kinetics between wheat and rape when determined under the same conditions of determination. The isotherm of No3- uptake by wheat could be separated into saturated and unsaturated parts, and when the concentration of No3- exceeded 180 uuuuuuuuuuuuM, the relationship between the rate of No3- uptake and No3- concentration tended to be linear. However, the isotherm of No3- uptake by rape was found to fit the Michealis-Menten equation and no linear relationship could be found.

关键词： double ion-selective electrode method kinetic parameter nitrate

Speciation and fractionation of heavy metals in soil experimentally contaminated with pb, Cd, Cu and Zn together and effects on soil negative surface charge

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Journal of Environmental sciences 2002年第4期14卷 439-444页

作者： ZHoU Dong mei, HAo Xiu zhen, TU Cong, chen Huai man, SI You bin (Institute of soil science, Chinese Academy of sciences, nanjing 210008, China. )

Speciation and fractionation of heavy metals in soil subsamples experimentally loaded with pb, Cd, Cu and Zn in orthogonal design was investigated by sequential extraction, and operationally defined as water soluble and exchangeable(SE), weakly specific adsorbed(WSA), Fe and Mn oxides bound(oX) and organic bound(oRG). The results showed that fractions of heavy metals in the soil subsamples depended on their speciation. About 90% of Cd and 75% of Zn existed in soil subsamples in the SE fraction. Lead and Cu existed in soil subsamples as SE, WSA and oX fractions simultaneously, although SE was still the major fraction. organic bound heavy metals were not clearly apparent in all the soil subsamples. The concentration of some heavy metal fractions in soil subsamples showed the good correlation with ionic impulsion of soil, especially for the SE fraction. Continuous saturation of soil subsamples with 0.20 mol/L NH 4Cl, which is the first step for determination of the negative surface charge of soil by the ion retention method, resulted in desorption of certain heavy metals from the soil. It was found that the percentage desorption of heavy metals from soil subsamples depended greatly on pH, the composition and original heavy metal content of the soil subsamples. However, most of the heavy metals in the soil subsamples were still be retained after multiple saturation. Compared with the parent soil, the negative surface charge of soil subsamples loaded with heavy metals did not show difference significantly from that of the parent one by statistical analysis. Heavy metals existed in the soil subsamples mainly as exchangeable and precipitated simultaneously.

关键词： soil heavy metals speciation soil surface charge

Fractionation of Heavy Metals in soils as Affected by soil Types and Metal Load Quantity

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pedosphere 2002年第4期12卷 309-319页

作者： ZHoU DoNGMEI, chen HUAIMAN, HAo XIUZHEN and WANG YUJUNInstitute of soil science, the Chinese Academy of sciences, nanjing 210008 (China) Institute of soil science the Chinese Academy of Sciences Nanjing 210008

Two series of soil subsamples, by spiking copper (Cu), lead (pb), zinc (Zn) and cadmium (Cd) in an orthogonal design, were prepared using red soil and brown soil, respectively. The results indicated that heavy metal fractions in these soil subsamples depended not only on soil types, but also on metal loading quantity as well as on interactions among metals in soil. Lead and Cu in red soil appeared mostly in weakly specifically adsorbed (WSA), Fe and Mn oxides bound (oX), and residual (RES) fractions. Zinc existed in all fractions except organic bound one, and Cd was major in water soluble plus exchangeable (SE) one. Different from the results of red soil, pb and Cu was present in brown soil in all fractions except organic one, but over 75% of Zn and 90% of Cd existed only in SE fraction. Meanwhile, SE fraction for any metal in red soil was lower than that in brown soil and WSA and oX fractions were higher. It is in agreement with low cation exchange capacity and large amounts of metal oxides included in red soil. Metal fractions in soil, especially for water soluble plus exchangeable one, were obviously influenced by other coexisting metals. The SE fraction of heavy metals increased with increasing loading amounts of metals in red soil but not obviously in brown soil, which suggest that metal availability be easily affected by their total amounts spiked in red soil. In addition, more metals in red soil were extracted with 0.20 mol L-1 NH4Cl (pH 5.40) than that with 1.0 mol L-1 Mg(No3)2 (pH 7.0), but the reverse happened in brown soil, implicating significantly different mechanisms of metal desorption from red soil and brown soil.

关键词： fraction heavy metal interaction ionic impulsion soil

Effects of Different Lead Compounds on Growth and Heavy Metal Uptake of Wetland Rice

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pedosphere 1991年第3期1卷 253-264页

作者： chenHUAI－MAN ZHENGCHUN－RoNG 等 LMCp，Instituteofsoilscience AcademiaSinicaP.O.Box821Nanjing210008（China） LMCp，InstituteofsoilScie

Effects of different lead compounds, pbCl2, pb(No3)2 and pb(oAc)2, on the rice growth and uptake of lead and some microelements by wetland rice were studied. The results showed that the seed germination, rice seedling growth, chlorophyl content, grain yield and uptake of pb, Cu, Zn, Fe and Mn by rice plant were affected by the chemical forms of pb compounds added in soil to a certain degree. The germination rate and the amount of chlorophyl decreased remarkably with increasing pb concentration, the root extension was restrained obviously by the presence of pb, and the effect of pbCl2 was more evident than that of pb(No3)2 or pb(oAc)2. The pot incubation test with yellow brown soil and red soil showed that there was no significant regularity in effect of pb on grain yield, but the difference in the influence of various pb compounds on yield was clearer. The effect on the amount of pb in straw and brown rice was in the sequence of pb(No3)2> pb(oAc)2> pbCl2. In case the content of pb in brown rice was 0.5 mg/ kg, the relative loading capacities of yellow brown soil for pb added as pbCl2, pb(oAc)2 and pb(No3)2 were 100, 90 and 60 respectively. pb uptake by wetland rice was closely related to the chemical species of pb in soil, but there was no comparability among chemical forms of different pb compounds in the same soil. The uptake of Cu, Zn, Fe and Mn by wetland rice was markedly affected by the addition of pb, and different pb compounds varied in their impacts on the uptake of other metals by different organs of wetland rice, e.g. the concentration of Fe in root increased significantly (r = 0.92), while opposite was true for Fe in brown rice (r =-0.92) due to the application of pb(oAc), in soil. These results demonstrate that the effect of accompanying anions of pb on the physiological and biochemical processes of wetland rice was rather complex.

关键词： anion loading capacity of soil microelement pb rice

potassium Fractions in soils as Affected by Monocalcium phosphate,Ammonium Sulfate,and potassium Chloride Application

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pedosphere 2010年第3期20卷 368-377页

作者： WANG Huo-Yan, ZHoU Jian-Min, DU Chang-Wen and chen Xiao-Qin State Key Laboratory of soil and Sustainable Agriculture, Institute of soil science, Chinese Academy of sciences, nanjing 210008 (China) [a] State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China)

soil potassium （K） deficiency has been increasing over recent decades as a result of higher inputs of N and p fertilizers concomitant with lower inputs of K fertilizers in China; however, the effects of interactions between N, p, and K of fertilizers on K status in soils have not been thoroughly investigated for optimizing N, p, and K fertilizer use efficiency. The influence of ammonium sulfate （AS）, monocMcium phosphate （MCp）, and potassium chloride application on K fractions in three typical soils of China was evaluated during 90-d laboratory soil incubation. The presence of AS significantly altered the distribution of native and added K in soils, while addition of MCp did not significantly affected K equilibrium in most cases. Addition of AS significantly increased water-soluble K （WSK）, decreased exchangeable K （EK） in almost all the soils except the paddy soil that contained considerable amounts of 2：1 type clay minerals with K added, retarded the formation of fixed K in the soils with K added, and suppressed the release of fixed K in the three soils without K added. These interactions might be expected to influence the K availability to plants when the soil was fertilized with AS. To improve K fertilizer use efficiency, whether combined application of AS and K was to be recommended or avoided should depend on K status of the soil, soil properties, and cropping systems.

关键词： fertilizers K availability K fixation K release

Effect of potassium Nutrition of Different Varieties of Rice on the Redox Status in Microzone Rhizosphere soils

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pedosphere 1992年第4期2卷 337-344页

作者： chenJI－XING XUANJIA－XIANG 等 Instituteofsoilscience AcademiaSinicaP.O.Box821Nanjing210008（China） Instituteofsoilscience Academia

Being divided into three groups-strong, moderate and weak-according to the different kinetic parameters (Fmax, km, Cmin) of potassium uptake by crops, 21 cultivars of rice have been studied to find out the relationships between their potassium nutrition and the oxidation-reduction status in the rhizosphere *** show that, with no application of K fertilizer, there were higher contents of active reducing substances and ferrous iron in rhizosphere soils planted with cultivars, such as Zhongguo 91, week in absorbing potassium than in soils cropped with cultivars, Shanyou 64, stronger in absorbing potassium. As a result of K application, however, these toxic substances were decreased appreciably in the soil, particularly in the root zone where weakly K-absorbing cultivars were growing, and the parameter of soil redox (pH +pE) was increased, the most striking example of this being found in the rhizosphere soil where the more strongly K-absorbing cultivars were growing. on and close to the root surface in soils where rice plants were supplied with potassium fertilizer, rather more iron oxide had been accumulated compared with rice receiving no potash, and even greater amounts of red iron oxide precipitated on the rice root in neutral paddy soils. As shown by the concentration distribution of active reducing substances and ferrous iron in a microzone of the profile, the redox range of rice roots supplied with potassium may extend as far as several centimeters from the root surface. It can thus be seen that potassium nutrition exerts its effect first on the morphological properties of rice roots and their exudation of oxygen, then on the content of soluble oxygen and the count and species of oxygen-consuming microbes in the rhizosphere soil, and finally on the redox status of the soil.

关键词： potassium nutrition redox status rice cultivar

Influence of Chelating Agents on Chromium Fate in Sediment

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pedosphere 1996年第2期6卷 163-166页

作者： WANG XIAoCHANG SUN JINHE ZHANG QINZHENG CAo zhiHoNG and chen ZIYUAN(Institute of soil science,Academia sinica,nanjing 210008 China)(Zhejiany Agricultural University,Hangzhou 310029 China) Instituteofsoilscience AcademiaSinicaNanjing210008China ZhejiangAgriculturalUniversity Hangzhou3100

A laboratory investigation on reaction between chelating agents and chromium was conducted to evaluate the effect of chelating agents on the adsorption and desorption of chromium in sediment. The amount of adsorbed chromium(VI) in sediment decreased slightly by 5%-10% because of addition of chelating *** agents inhibited the remodel of Cr(Ⅲ) by sediment from solutions and the inhibiting effect was in the order:citric acid > tartaric acid > EDTA, salicylic *** effect of chelating agents on desorption of chromium in sediment was observed.

关键词： adsorption chelating agent Cr desorption sediment

Characterization of Humic Fractions in a ^(15)N-labelled soil by Solid-State ^(13)C and ^(15)N NMR

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pedosphere 2001年第2期11卷 151-157页

作者： chenG LILI, WEN QIXIAo and chen BIYUN Institute of soil science, the Chinese Academy of sciences, nanjing 210008 (China)

Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4p207, 0.1 mol L-1 NaoH, and HF/HCI-0.1 mol L-1 NaoH, consecutively, and analyzed by 13C and 15N CpMAS NMR (cross polarization and magic angle spinning nuclear magnetic resonance). Compared with those of native soils humic fractions studied as a whole contained more alkyls, methoxyls and o-alkyls, being 27%-36%, 17%-21% and 36%-40%, respectively, but fewer aromatics and carboxyls (being 14%-20% and 13%-90%, respectively). Among those humic fractions, the humic acid (HA) and fulvic acid (FA) extracted by 0.1 mol L-1 Na4p207 contained slightly more carboxyls than corresponding humic fractions extracted by 0.1 mol L-1 NaoH, and the HA extracted by 0.1 mol L-1 NaoH after treatment with HF/HCI contained the least aromatics and carboxyls. The distribution of nitrogen functional groups of soil humic fractions studied was quite similar to each other and also quite similar to that of humic fraction from native soils. More than 75% of total N in each fraction was in amide form, with 9%-13% present as aromatic and/or aliphatic amines and the remainder as hoterocyclic N.

关键词： aromaticity 13C CpMAS NMR humic substances 15N CpMAS NMR nitrogen forms