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Effects of Nitrogen Fertilizer,Soil Moisture and Temperature on Methane Oxidation in Paddy Soil

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Pedosphere 1996年第2期6卷 175-181页

作者： YANXIAOYUAN CAIZUCONG lmcp，InstituteofSoilScience AcademicaSinicaNanjing210008China lmcp，InstituteofSoilScience Academi

Effects of nitrogen fertilizer,soil moisture and temperature on methane oxidation in paddy soil were investigated under laboratory conditions. Addition of 0.05 g N kg-1 soil as NH4Cl strongly inhibited methane oxidation and addition of the same rate of KCl also inhibited the oxidation but with more slight effect,suggesting that the inhibitory effect was partly caused by increase in osmotic potential in microorganism *** only NH but also NO greatly affected methane *** did not affect methane oxidation in paddy soil in the first two days of incubation,but strong inhibitory effect was observed *** was oxidized in the treated soil with an optimum moisture of 280 g kg-1, and air-drying inhibited methane oxidation *** optimum temperature of methane oxidation was about 30℃in paddy soil,while no methane oxidation was observed at 5℃or 50℃

关键词： methane oxidation nitrogen fertilizer paddy soil soil moisture temperature

Simulation of Methane Oxidation by Paddy Soils in a Closed System

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Pedosphere 1996年第4期6卷 313-320页

作者： CAIZUCONG YANXIAOYUAN lmcp，InstituteofSoilScience ChineseAcademyofSciencesNanjing210008China lmcp，InstituteofSoilScienc

Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of first-order-kinetics. According to the equation the change of soil ability to oxidize CH4 could be estimated by the equstion The results showed that the soil ability to oxidize CH4 varied, depending on the initial CH4 *** initial CH4 concentration stimulated soil ability to consume CH4, while low concentration depressed the ability. This characteristic of paddy soil seemed to be of considerable significance to self-adjusting CH4 emission from flooded rice fields if there exist oxic microsites in the soil.

关键词： methane oxidation paddy soils simulation

Combined Heavy Metal Pollution in Red Soil

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Pedosphere 1996年第4期6卷 305-312页

作者： CHENHUAIMAN ZHENGCHNURONG lmcp，InstituteofSoilScience AcademiaSinicaNanjing210008China lmcp，InstituteofSoilScience Academia

The effects of combined heavy metal pollution of red soil on the growth of wetland rice and the transfer of Pb, Cd, Cu and Zn from soil into plants were studied by greenhouse pot experiment. The results showed that the plat yields were markedly affected by heavy metals, with the exception of Pb, in soils under the experimental conditions, without taking into consideration all the interactions among the elements. The concentrations of the elements in plants were mainly affected by the specific element added to the soil. The effect of interactions among the heavy metals was very significant either on plant yields or on the concentration of the elements in plants. The risk assessment of a combined pollution by heavy metals in the soil is discussed preliminarily in terms of the relative pollution equivalent.

关键词： heavy metals rice risk assessment soil

Use　of　New　Water　Soluble　Surface　Film－Forming　Material　to　Reduce　Ammonia　Loss　from　Water　Solution

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Pedosphere 1996年第4期6卷 329-334页

作者： YINBIN SHENRENFANG 等 lmcp，InstituteofSoilScience AcademiaSinicaP.O.Box821Nanjing210008China lmcp，InstituteofSoilScien

A new water soluble surfaCe film-forming material was developed and its effect on reducing ammonia volatilization from an alkaline solution was investigated in laborstory. Results showed that the new film formed by the material was not only more effective in reducing ammonia loss than any other films tested but also much cheaper. The optimum amount of addition of the new film-forming material was about 10times the theoretical amount to form a monomolecular film. Under the experimental conditions, the new film could effectively depress the ammonia volatilization for at least 6 days. The cumulative ammonia loss rates for different films were fitted to a simple logistic equation, and some important parameters such as the cumulative loss, and the maximum and average volatilization rates were calculated. The effect of different films could be, therefore, compared quantitatively, indicating the new film was most effective in depressing ammonia volatilization.

关键词： ammonia loss logistic equation surface film-forming material

Study on Variation in ^(15)N Natural Abundance. Ⅰ. Characteristics of Variation in ^(25)N Natural Abundance of Forest Soils

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Pedosphere 1991年第3期1卷 277-281页

作者： SUNGUO－QING XINGGUANG－XI 等 lmcp，InstituteofSoilScience AcademiaSinicaNanjing210008（China） lmcp，InstituteofSoilScience Academi

INTRODUCTION A lot 0fwork has been done on the variation of natural ^(15)N abundance in soils andtheir N components (Chen et al., 1964). However, these reports mostly concerned thegeochemical mean of natural ^(15)N abundance, and only a little work has been done on thecharacteristics of variation of the natural ^(15)N abundance in different ecosystems and itsrelationship with the properties and conditions of soil, which is the aim of our recent re-

关键词： forest soil 15N natural abundance

Nitrogen Forms in Humic Substances

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Pedosphere 1992年第4期2卷 307-315页

作者： ZHUOSU－NENG WENQI－XIAO lmcp，InstituteofSoilScience AcademiaSinicaP.O.Box821Nanjing210008（China） lmcp，InstituteofSoilScie

In this paper,the nitrogen forms in newly-formed humic substances,including humic acid (HA),fulvic acid (FA) and humic acid in humin (HAI),were studied by using the ^15N CP-MAS NMR technique in combination with chemical *** show that the majority of nitrogen in HA,FA and HAI was in the amide form with some presented as aliphatic and/ or aromatic amines and some as pyrrole type nitrogen,although the contents of nonhydrolyzable nitrogen in them differed greatly from each other (15-55%).

关键词： fulvic acid humic acid 15N CP-M AS NMR nitrogen forms

Cr^(Ⅵ) adsorption on four typical soil colloids: equilibrium and kinetics

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Journal of Environmental Sciences 2000年第3期12卷 325-329页

作者： ZHOU Dong-mei CHEN Huai-man lmcp Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

It is observed that the adsorption of chromium are greater on kaolinite minerals, red soil (R) and laterite (L) colloids than that on montmorillonite, indicotic black (IB) and yellow brown (YB) soil colloids. The adsorption process of Cr Ⅵ on these media can be further described by Langmuir or Freundlich equation quite well. The adsorption reaction of Cr Ⅵ is fast, and the adsorption equilibrium can be reached within the first two hours in moderate temperature. The adsorption quantity of Cr Ⅵ to kaolinite mineral increased with the increasing pH in the range of 2.0 to 7.0, then decreased at higher pH. But it showed some consistence among the four soil colloids. The lower the pH, the stronger the adsorption. The possible mechanisms are further discussed here. Meanwhile the influence of temperature on Cr Ⅵ adsorption on different soil colloid and clay minerals are also investigated.

关键词： Cr Ⅵ soil colloids clay mineral adsorption

Nitrogen Forms in Synthetic Humic Acids Using Nitrogen-15 Nuclear Magnetic Resonance Technique

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Pedosphere 1993年第3期3卷 193-200页

作者： ZHUOSU－NENG WENQI－XIAO lmcp，InstituteofSoilScience AcademiaSinicaP.O.Box821Nanjing210008（China） lmcp，InstituteofSoilScie

^15N-labelled phenolic polymers were synthesized by reactions of p-benzoquinone and 1,4-diphenol with ^15N-labelled glycine and were studied by using ^15N CP-MAS NMR technique in combination with chemical *** showed that the proportion of polymer nitrogen as N-phenyl amino acid N was not as great as expected,only accounting for 5%-15%;and most of N in polymers occurred in the forms of amide,pyrrole-and indole-like nitrogen,aliphatic amines and *** seems that great differences existed between synthetic humic acids and soil humic acids in the type and distribution of nitrogen forms.

关键词： 15N CP-MAS NMR N-phenyl amino acid nucleophilic addition reaction

Degradation of Soil Properties due to Erosion on Sloping Land in Southern Jiangsu Province,China

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Pedosphere 2004年第1期14卷 17-26页

作者： ZHANGYan PENGBu-Zhuo GAOXiang YANGHao lmcp InstituteofSoilScienceChineseAcademyofSciencesNanjing210008（China） DepartmentofUrbanandResourcesScience NanjingUniversityNanjing210093（China）

Soil erosion accelerates soil degradation. Some natural soils and cultivated soils on sloping land in southern Jiangsu Province, China were chosen to study soil degradation associated with erosion. Soil erosion intensity was investigated using the 137Cs tracer method. Soil particle-size distribution, soil organic matter (OM), total nitrogen (TN) and total phosphorus (TP) were measured, and the effects of erosion on soil physical and chemical properties were analyzed statistically using SYSTAT8.0. Results indicated that erosion intensity of cultivated soils was greater than that of the natural soils, suggesting that cultivation increased soil loss. Erosion also led to an increase of coarser soil particle proportion, especially in natural soils. In addition, silt was the primary soil particle lost due to erosion. However, in cultivated fields, coarser soil particles over time were attributed not only to soil erosion but also to mechanical eluviation as a result of farming activities. Moreover, erosion caused a decrease in soil OM, TN and TP as well as thinning of the soil layer.

关键词： ^(137)Cs coarser soils nutrients soil degradation soil layer