不同施肥处理红壤生物活性有机碳变化及与有机碳组分的关系

采用物理分组方法对长期不同施肥处理的旱地红壤有机碳组分进行了区分,布置室内培育试验观测了培养过程中土壤有机碳的矿化动态,通过拟合一级动力学方程计算土壤生物活性有机碳库量.研究结果表明,不同施肥处理的土壤中,轻组有机碳(LF-C)、团聚体包裹的粗颗粒有机碳(iPOMc-C)及细颗粒有机碳(iPOMf-C)、矿物结合态有机碳(mSOC)分别占总有机碳的7%～10%、0.5%～1.5%、4%～7%、76%～85%,并与总有机碳(TOC)含量显著相关;厩肥处理显著增加了各组分含量,其作用优于绿肥处理和单施无机肥处理(CK);培养过程中土壤有机碳矿化动态符合一级反应动力学方程;有机无机肥配施处理的土壤生物活性有机碳库(C0)显著提高;和绿肥相比,厩肥处理中生物活性有效碳库(C0)增加幅度更大,但其周转速率常数k更小;各组分有机碳含量与C0含量均达到极显著(p＜0.01)相关,但除LF-C外其余有机碳组分占TOC的百分率均与C0达到极显著水平.     

Dynamic Relationship Between Biologically Active Soil Organic Carbon and Aggregate Stability in Long-Term Organically Fertilized Soils

Biologically active soil organic carbon (BASOC) is an important fraction of soil organic carbon (SOC), but our understanding of the correlation between BASOC and soil aggregate stability is limited. At an ecological experimental station (28°04 -28°37 N, 116° 41 -117° 09 E) in Yujiang County, Jiangxi Province, China, we analyzed the dynamic relationship between soil aggregate stability and BASOC content over time in the red soil (Udic Ferrosols) fertilized with a nitrogen-phosphorus-potassium chemical fertilizer (NPK) without manure or with NPK plus livestock manure or green manure. The dynamics of BASOC was evaluated using CO2 effux, and soil aggregates were separated according to size using a wet-sieving technique. The soils fertilized with NPK plus livestock manure had a significantly higher content of BASOC and an improved aggregate stability compared to the soils fertilized with NPK plus green manure or NPK alone. The BASOC contents in all fertilized soils decreased over time. The contents of large aggregates (800-2000 μm) dramatically decreased over the first 7 d of incubation, but the contents of small aggregates (< 800 μm) either remained the same or increased, depending on the incubation time and specific aggregate sizes. The aggregate stability did not differ significantly at the beginning and end of incubation, but the lowest stability in all fertilized soils occurred in the middle of the incubation, which implied that the soils had a strong resilience for aggregate stability. The change in BASOC content was only correlated with aggregate stability during the first 27 d of incubation.     

Particulate Organic Matter in Noncultivated and Arable Soils

Eurasian Soil Science - Data on the contents of particulate organic matter (POM) in the humus horizons of different soil types were obtained. The influence of the land use system and fertilizers on...     

Soluble Organic Matter in Soils of the Rostov Agglomeration

Eurasian Soil Science - Specific features of humus accumulation and migration of water-soluble organic matter (WSOM) extracted by cold and hot distilled water in soil profiles were studied. The...     

曲靖市耕地土壤有机质状况

2006—2011年,采集曲靖市耕地12个土类13 171个土壤样品,进行有机质测定,了解曲靖市耕地土壤有机质状况。结果表明,与第二次土壤普查结果相比,曲靖市耕地不同土类土壤有机质有升有降。其中,赤红壤、水稻土、紫色土、冲积土和燥红土有机质平均含量分别升高13.0%、16.8%、19.5%、52.5%和222.4%;而草甸土、黄壤、红壤、石灰(岩)土、黄棕壤、棕壤和沼泽土平均含量则分别降低了6.2%、17.7%、19.6%、32.3%、36.0%、42.9%和74.1%。从面积上来看,80.8%的旱作耕地土壤有机质平均含量低于第二次土壤普查结果,这意味着曲靖市旱作耕地土壤质量有所退化。耕地土壤管理中需加强绿肥生产利用、秸秆还田,提升土壤有机质。     

Decomposition of Organic Matter with Previous Cadmium Adsorption in Soils

Decomposition of organic matter with previous Cd adsorption (thereafter referred to as OMACd) in soils and in water was studied in order to clarify the mechanism of Cd-induced inhibition of organic matter decomposition in soil. Two types of organic materials (sludge, rice straw) with or without previous Cd adsorption were mixed with a Gley soil or a Light-colored Andosol in a proportion of 1%. In the soils amended with the Cd-free organic materials, a CdCl₂ solution was added to the soils. The decomposition of the organic matter was examined by measuring the CO₂ evolution for 4 weeks at 28°C. Although the same amount of Cd was added to the soils, the decomposition of OMACd was inhibited to a greater extent than that in the soils to which a CdCl₂ solution had been added.

Furthermore the decomposition of sludge with previous Cd adsorption (thereafter referred to as SACd) in water after inoculation of soil microorganisms was investigated. Although the control sludge without Cd was markedly decomposed at 30°C during 4 weeks, SACd was not appreciably decomposed. These results suggest that OMACd cannot be readily decomposed by microorganisms.     

Organic Matter and Mineralizable Nitrogen Relationships in Wetland Rice Soils

Abstract

Soil nitrogen (N) supply plays a dominant role in the N nutrition of wetland rice. Organic matter has been proposed as an index of soil N availability to wetland rice. This is based on the finding that mineralizable N produced under waterlogged conditions is related to soil organic carbon (C) and total N. The relationship between organic matter and mineralizable N is a prerequisite for determining the N requirement of wetland rice. However, no critical analysis of recent literature on organic matter–mineralizable N relationships has been made. This article evaluates current literature on the relationships of mineralizable N or ammonium N production with soil organic C in wetland rice soils. A number of studies with diverse wetland rice soils demonstrate a close relationship of N mineralized (ammonium‐N) under anaerobic conditions with organic C or total N. However, a few recent studies made on sites under long‐term intensive wetland rice cropping showed that strong positive relationships of mineralizable N with organic C or total N do not hold. Clearly, both quantity and quality of organic matter affect N mineralization in wetland rice soils. Future research is needed to clarify the role of quality of organic matter, especially its chemistry, as modified by the chemical environment of submerged soils, on the mineralization of organic N in wetland rice soils.     

长期施肥对土壤生物活性有机碳库的影响

采用土壤培养实验方法,研究了25年施肥对平凉黑垆土土壤生物活性有机碳库(C0)的影响。结果表明:土壤生物活性有机碳库(C0)以施用有机肥处理显著增大,其中以S+NP处理最高,达1071.00μg/g,M+NP处理为940.85μg/g,M处理为776.90μg/g,分别比CK增加1.86倍、1.51倍和1.07倍,单施N肥处理对土壤生物活性有机碳库影响不大,为399.10μg/g,仅比CK增加6.4%,NP配合处理为621.60μg/g,比CK增加65.76%。增施有机肥料可明显增大土壤生物活性有机碳库(C0),NP化肥配合施用也有良好效果,N肥单施无明显作用。土壤生物活性有机碳库(C0)占土壤总有机碳(TOC)的百分比为2.70%～6.34%,生物活性有机碳库的周转速率(K)为0.0223～0.0301d-1,生物活性有机碳库在土壤中的半周转期(T1/2)为22.55～31.09d。土壤生物活性有机碳库(C0)与土壤全氮呈极显著性正相关,与总有机碳(TOC)呈显著性正相关。     

Nonhydrolyzable Part of Soil Organic Matter in Buried and Modern Soils

Eurasian Soil Science - Results of the study of humus composition in about 200 modern soils of different genesis and more than 100 buried Pleistocene and Holocene paleosols have been collected and...     

杭州市城市土壤有机碳的积累和特性

杭州市城市土壤有机碳具明显的积累并具较大的空间变异性,城区土壤表土(0~10 cm)和0~100 cm深度土壤平均有机碳贮量约为远郊区土壤的4.3和5.7倍。城市土壤有机碳中含较高比例的碳黑、颗粒态碳和较低比例的易氧化态碳,表明城市土壤有机碳较为稳定。随着人为影响程度的增加,土壤碳黑、颗粒状碳量增加,易氧化态碳的数量减少。     

Cultivation-Induced Effects on the Organic Matter in Degraded Southern African Soils

We studied quantitative and qualitative changes in soil organic matter (SOM) due to different land uses (reference woodland versus cultivated) on six soils from Tanzania (Mkindo and Mafiga), Zimbabwe (Domboshawa and Chickwaka), and South Africa (Hertzog and Guquka). Structural characteristics of the humic acids (HAs) were measured by Curie-point pyrolysis–gas chromatography/mass spectrometry (P_y–GC/MS) and solid-state ¹³C nuclear magnetic resonance (CPMAS ¹³C NMR) spectroscopy. Significant changes in concentration and composition of SOM were observed between land uses. Losses of organic carbon after cultivation ranged from 35% to 50%. Virgin soils showed large proportions of colloidal humus fractions: humic acids (HAs) and fulvic acids (FAs) but negligible amounts of not-yet decomposed organic residues. The change in land use produced a contrasting effect on the composition of the HAs: a noteworthy “alkyl enhancement” in Mkindo soil and “alkyl depletion” in Chikwaka and to a lesser extent in Domwoshawa. The remaining soils displayed only minor alterations.     

土壤活性有机质的研究进展

本文简要综述了土壤活性有机质及其应用的研究进展,包括活性有机质的概念及其测定方法、活性有机质与土壤养分供应、土壤理化性质的关系及其活性有机质在反映土壤肥力综合评价土壤质量等方面的应用.     

Patterns of Organic Matter Accumulation in Soils of the Semiarid Argentinian Pampas

A-horizons of 48 Haplic Phaeozems and Kastanozems in plain sites of the Semiarid Argentinian Pampas under three contrasting management systems (virgin bushland, permanent pasture and continuous agriculture) were studied. Morphological characteristics, organic carbon and total nitrogen levels and E4:E6 ratios were determined on the assumption that both quantity and quality of organic matter should be related to soil texture of parent materials in this region since other soil forming factors are uniform. The more intensive land use produced an averaged decrease of 7 cm in A-horizon thickness and degradation of soil structure, but little changes in color and properties of boundaries to AC horizons. In virgin soils organic carbon and nitrogen contents correlate with silt + clay fractions (r = 0,92 and 0,99, respectively), while E4:E6-ratios are related to clay contents (r = ?0.69*) confirming the strong influence of soil texture. Agricultural-management and pasture use of soils lead to dispersion of these correlations probably because of differential influence of varying intensities of land use within each management system. Soils under continuous agriculture show lower organic carbon contents than virgin soils only at clay + silt > 40%. Eragrostis curvula-pastures seems to be more effective in restoring organic matter and nitrogen levels in sandy but not in loamy soils with respect to virgin soils. This may be due to a better efficiency of E. curvula-roots in coarse than in fine textured soils to produce humificable residues than the autochthonous grass species.     

Ectomycorrhizal Formation in Herbicide-Treated Soils of Differing Clay and Organic Matter Content

Herbicides are commonly used on private timberlands in the western United States for site preparation and control of competing vegetation. How non-target soil biota respond to herbicide applications, however, is not thoroughly understood. We tested theeffects of triclorpyr, imazapyr, and sulfometuron methyl on ectomycorrhizal formation in a greenhouse study. Ponderosa pine, Douglas-fir, and white fir seedlings were grown in four forest soils ranging in clay content from 9 to 33% and organic matter content from 3 to 17%, and treated with commercial formulations of each herbicide at 0, 1.0, and 2.0 times the recommended field rate. Many of the possible herbicide-soil combinations resulted in reduced seedling growth. Root development was particularly sensitive to the three herbicides, with an average of 51% fewer root tips compared to the control treatment. The ability of mycorrhizal fungi to infectthe remaining root tips, however, was uninhibited. Mycorrhizal formation was high, averaging 91% of all root tips, regardless of herbicide, application rate, soil type, or conifer species. In agreement, soil microbial biomass and respiratory activity were unaffected by the herbicide treatments. The results show that these herbicides do not alter the capability of mycorrhizal fungi to infect roots, even at concentrations detrimental to seedling growth.     

Microbiological Transformation of Organic Matter in Oil-Polluted Tundra Soils after Their Reclamation

Eurasian Soil Science - The influence of oil pollution caused by the accident of 1994 on the biological activity of Histic Cryosols is considered. Despite the use of complex mechanical (oil...     

长期不同施肥处理水稻土溶解性有机质组分含量及其特性研究

基于长期定位试验研究不同施肥处理下土壤溶解性有机质量(DOM)组分含量及其特性。研究表明:不同量化肥施用土壤DOC含量没有显著增加,而施用化肥,配施秸秆能显著增加耕层土壤DOC含量,配施猪粪能显著提高耕层和犁底层土壤DOC含量。施化肥以及化肥有机肥配施均能显著提高土壤各层DON含量,除耕层C2外。施化肥后土壤无机态氮含量增加,DON比例下降,化肥配施猪粪后土壤DON含量和比例显著增加。施用C1+M处理土壤DOP含量均显著高于其他处理,并促进磷向下层迁移,而其他施肥处理之间差异不明显。耕层土壤DP含量显著高于犁底层和渗育层,C1+M、C2+S、C3均能显著提高土壤DP含量,且向深层迁移明显。施化肥以及化肥有机肥配施均能显著提高土壤DS含量,化肥有机肥配施处理增幅尤为显著。施化肥以及化肥有机肥配施均能提高土壤UV280,而化肥有机肥配施显著有利于土壤DOM芳香性结构更具复杂化与稳定性,特别是C1+M。DOM组分间显著相关性分析表明土壤DOM各组分之间是密切相关,相互联系的。     

Reactive Modeling of Denitrification in Soils with Natural and Depleted Organic Matter

Nitrogen fertilizers used in agriculture often cause nitrate leaching towards shallow groundwater, especially in lowland areas where the flat topography minimize the surface run off. In order to introduce good agricultural practices that reduce the amount of nitrate entering the groundwater system, it is important to quantify the kinetic control on nitrate attenuation capacity. With this aim, a series of anaerobic batch experiments, consisting of loamy soils and nitrate-contaminated groundwater, were carried out using acetate and natural dissolved organic matter as electron donors. Acetate was chosen because it is the main intermediate species in many biodegradation pathways of organic compounds, and it is a suitable carbon source for denitrification. Sorption of acetate was also determined, fitting a Langmuir isotherm in both natural and artificially depleted organic matter soils. Experiments were performed in quadruplicate to account for the spatial variability of soil parameters. The geochemical code PHREEQC (version 2) was used to simulate kinetic denitrification using Monod equation, equilibrium Langmuir sorption of acetate, and equilibrium reactions of gas and mineral phases (calcite). The reactive modeling results highlighted a rapid acetate and nitrate mineralization rate, suggesting that the main pathway of nitrate attenuation is through denitrification while calcite acted as a buffer for pH. However, in the absence of acetate, the natural content of organic matter did not allow to complete the denitrification process leading to nitrite accumulation. Reactive modeling is thought to be an efficient and robust tool to quantify the complex biogeochemical reactions which can take place in underground environments.     

The Content and Composition of Organic Matter in Soils of the Subpolar Urals

Eurasian Soil Science - Soil organic matter at high latitudes is an important and sensitive indicator of climate change. This article describes the main morphological features, chemical properties,...     

Characterization of the Soil Organic Matter in Agricultural Mine Spoils and Reclaimed Soils Treated with Organic Amendments

Recycling organic waste in agricultural soils is a valid solution. We performed short‐term experiments to investigate the fate of urban sludge and composts, in mine spoils, cultivated or uncultivated, and reclaimed soils located in Florence and Milan, Italy. The samples, either treated or untreated, were fractionated by density into light (<1.63 Mg m^?3) and heavy (>1.63 Mg m^?3) fractions. The fractions were analyzed for total carbon (C) and nitrogen (N) contents and for δ ¹³C and δ ¹⁵N isotopes, and they were characterized by ¹³C NMR spectroscopy. Treatment increased the heavy fraction. The addition of sludge in the Florence area acts in synergy with the cultivation, increasing the light fraction (LF). In the Milan area, the LF tends to be decomposed and apparently transformed into HF. The addition of amendments or cultivation enhances the decomposition with release of carbon dioxide. For future research, we suggest lengthening the time of the experiments to integrate climatic variations.     

黄棕壤中活性有机碳对Cu吸附的影响

通过盐酸酸化法来去除4种不同利用方式黄棕壤的活性有机碳（AOC）,得到相对稳定的有机碳土壤,用于研究去除活性有机碳前后对Cu2＋吸附行为的影响。结果表明,黄棕壤去除有机碳前后,对Cu2＋吸附量与平衡液浓度的关系符合Langmuir方程和Freundlich方程,其拟合都呈现极显著相关（P〈0.01）,去除AOC后,黄棕壤各层次对Cu2＋的最大吸附量明显降低,是原土Cu2＋最大吸附量的10%～30%。盐酸酸化法对4种不同利用方式的黄棕壤有机碳的去除率为30%～75%,对Cu2＋吸附的减少率为54%～86%。去除活性有机碳前后,有机碳含量与对Cu2＋的吸附量都呈显著线性相关。土壤有机碳的去除率与对Cu2＋吸附的减少率间相关性达到极显著水平。