皖南山区土壤酸化趋势研究——以宣城市广德县为例

皖南山区土壤出现了酸化趋势,本文以具有代表性的宣城市广德县为例,通过将最新一轮土壤调查与第二次土壤普查的土壤pH值进行对比分析, 从总体、主要土壤类型、农用地类型以及空间分布4个方面,系统地研究了土壤酸化的趋势及其影响因素,并结合区域实际情况,提出了相应的土壤酸化防治对策.     

The relation between soil acidification and element cycling

Controversy about the contribution of acidic deposition to soil acidification partly arises from different concepts of soil acidification. Differentiating between actual and potential soil acidification has proved to be appropriate for properly identifying and quantifying the natural and anthropogenic sources of protons. Actual soil acidification is primarily manifested by leaching of cations from the soil, regulated by the mobility of major anions. Leaching of HCO₃ ^? and RCOO^? occurs naturally whereas leaching of NO₃ ^? and SO₄ ^2? is mainly caused by land use in agricultural soils and by acidic deposition in forest soils. Potential soil acidification is primarily due to accumulation of atmospherically derived N and S. This potential acid threat is partly realized by mineralization processes after the removal of vegetation.     

长期不同施肥下小麦离子吸收对土壤酸化贡献能力的比较

农业生产中长期不合理施肥导致土壤严重酸化,除了硝化作用和硝酸盐淋溶,作物对阳离子吸收是另一个重要的土壤酸度来源。本研究基于湖南祁阳红壤实验站农田25年长期定位试验研究了长期不同施肥下小麦阴阳离子吸收对土壤酸化贡献能力的变化。结果表明:长期施用化学氮肥显著降低土壤pH,影响小麦生物量,而施用有机肥可缓解土壤酸化,提高小麦生物量;单位面积土壤中小麦吸收阴阳离子对酸化的潜在贡献能力,即小麦产生的总质子量的大小顺序为:有机肥处理(M)氮磷钾配施有机肥处理(NPKM)磷钾肥处理(PK)氮磷钾肥处理(NPK)不施肥处理(CK)氮磷肥处理(NP)氮钾肥处理(NK)。相关性分析显示,小麦产生的总质子量与土壤pH、有效磷含量和地上部总生物量均呈显著正相关,而土壤pH和有效磷含量均与小麦地上部生物量呈显著正相关。因此,长期施肥的农田土壤中,随着酸化程度的加深,作物通过阴阳离子吸收对土壤酸化的贡献能力减弱,主要原因在于低土壤pH和有效磷含量限制了作物的生长,降低了作物的生物量。     

基于Web of Science和万方专利对土壤酸化和改良材料研究的计量分析

土壤酸化问题在近年来广受土壤和环境领域关注。为探索土壤酸化和改良材料应用现状，本文以Web of Science核心合集和万方专利数据库为基础，以“acid* soil*” or “soil acidi*”为检索式检索1990-2019年的期刊论文，以“酸化/酸性土壤改良剂/调理剂”为主题词检索2010-2019年的发明专利，分别检索出10193篇期刊论文和297篇发明专利，采用VOSviewer、CiteSpace和HistCite等可视化软件对关键词、期刊、作者、机构、国家等字段进行共现、共被引和引文分析等。结果表明土壤酸化及其改良材料得到越来越多的重视，进一步加强土壤酸化及其改良研究对土壤基础科学发展具有重要意义；研究领域聚焦于土壤酸化的生物化学过程、土壤铝毒及其防治、土壤重金属活化及其钝化、土壤酸化及其改良材料应用四大方面；近10年来，土壤酸化改良主要聚焦于石灰、农业废弃物/副产品、工业废弃物/副产品和矿物类等热点改良材料，而生物质炭、天然高分子、腐植酸盐和微生物菌剂等新型热点材料越来越受到学者的关注；高产国家美国、中国和澳大利亚等农业大国合作关系密切；高产机构中国科学院、中国科学院大学和西澳大学等机构有密切合作关系；高产作者Baligar VC，Xu renkou，Fageria NK等有密切合作关系。本研究有助于全面了解土壤酸化及其改良研究领域现状和趋势，为土壤酸化调控和可持续发展提供重要参考和依据。     

Effects of stopping liming on abandoned agricultural land

It is suggested that stopping liming on agricultural land could lead to a potential chemical time bomb (CTB). the sequence of interrelated events leading to the CTB include the end of liming, perhaps caused by a change in land use, a progressive decrease in soil pH and increased solubility of potentially toxic contaminants that accumulate in soils as a result of agricultural practices. Data are presented on rates of long-term soil acidification and modelled changes in the solubility of some trace metals in soil as a result of acidification. Soil acidification rates depend primarily on acid input rates and the soil's acid neutralizing capacity, possibly limited by neutralization kinetics. Experimental data illustrating this point show that the pH decreased rapidly in a field soil receiving ammonium rather than nitrate fertilizer treatment. on a limed agricultural field that was later abandoned and converted to deciduous woodland, The pH of the 0-23 cm soil layers decreased over 100 years from pH 7 to 4.2. Deeper layers acidified at a slower rate. Thermodynamic model calculations simulating the solubilities of metals in a sandy topsoil showed zinc, cadmium and aluminium solubilities increasing exponentially with decreasing pH, resulting in several-fold solubility increases between pH 5 and 4. These results suggest how metal solubility increases after liming stops. the model pH-solubility relationships depended on the type of metal, The solid phase controlling the solubility, and the amount of metal in the soil if adsorption controlled the solubility. Decreasing pH and the resultant increase in metal solubility expected on abandoned farmland might be managed through techniques such as liming or planting forests of selected tree species.     

生物质炭对茶园土壤改良及茶叶品质的影响

近年来,茶树种植过程中化肥的超量施用造成茶园土壤酸化加剧和有机质含量降低等一系列问题,进而影响到茶叶的产量和品质。生物质炭一般呈碱性,具有含碳量高、比表面积大、高度生物化学稳定性和较强的吸附性能等特性,能够增加土壤碳储量,提高土壤pH值和养分有效性,对于茶园土壤固碳、土壤改良和抑制土壤氮磷流失、改善农产品品质等方面有较大作用。针对我国茶园土壤存在的主要问题,以生物质炭的特性及生物质炭改良土壤的作用机理为研究对象,重点阐述了生物质炭在茶园酸化土壤改良、土壤氮素淋失阻控、土壤固碳增汇等方面的效应,以及生物质炭提高茶叶产量和提升茶叶品质方面的作用机理。基于以上研究,展望了生物质炭在茶园管理方面的理论研究方向,为生物质炭在农业生产中的应用和推广提供科学依据。     

三元复合肥料的酸度特征及其对土壤酸化的影响

针对目前农田土壤酸化严重,而酸性复合肥在农业生产中广泛施用,其本身的酸度特征及其对土壤酸化的促进作用程度不清的问题,本研究对目前市面上12种国内外生产的氮磷钾三元复合肥料进行了调查,发现11种复合肥料呈酸性,其中pH为4.0～5.0的肥料达58％以上,含酸量可高达1.95 mol/kg,这些酸性肥料施入土壤中1 d内可...     

中国酸性土壤利用的科学问题与策略

中国土壤酸化呈现出全国普遍发生的趋势,对作物产量、农产品品质和生物多样性造成不利影响。自20世纪50年代以来,我国在酸性土壤方面开展了大量工作,取得显著成效,但因我国酸性土壤分布详情不明、土壤酸化机制存在争议、耐逆作物品种缺乏、作物酸害阈值不清、改良产品及技术落地性差等问题,酸性土壤利用仍受到极大限制。针对上述问题,绘制了新的中国土壤酸碱度图,明确了我国酸性土壤的分布详情,讨论了土壤酸化机制特别是氮肥与土壤酸化之间的关系,论述了土壤酸化的危害,解析了植物和微生物对酸性土壤的响应和适应机制,提出了分区分级分类改良、酸度改良和肥力提高并重、有机无机肥配施、发展特色农业等酸性土壤改良和利用策略,建议进一步加强酸性土壤新型改良剂、作物酸害阈值、氮肥高效利用、中微量元素、耐逆作物育种和土壤酸化模型等方面研究,以期为酸性土壤可持续利用提供支撑。     

Spatial distribution,food chain translocation,human health risks,and environmental thresholds of heavy metals in a maize cultivation field in the heart of China’s karst region

Journal of Soils and Sediments - The overexploitation of resources such as mining and metallurgical and agricultural resources has resulted in heavy metal accumulation and soil acidification....     

中国土壤电化学的发展历程

本文介绍了土壤电化学研究历时50多年的系统成果,涉及带电粒子的化学行为、电极使用、学科渗透、工作成就、国内外影响和评价,形成集基本理论、实际应用和研究方法于一体的土壤电化学体系。在近期继承发展上,论述了电化学体系的土壤氧化还原过程及其研究法和酸化红壤修复原理与技术。前者扼要说明红壤中铝、锰离子的非等当量交换和非电性吸附;地跨湿润至干旱地区土壤氧化还原状况的水平带谱、垂直分异;有机还原性物质和无机氧化性物质的依存关系和变化规律,从而论证氧化还原过程作为土壤物质循环的转化动力(化学和生物学的)所作的贡献。后者扼要说明以铝化学为核心,土壤酸化理论、改良措施和从环保出发的工农业废弃物的利用;相反电荷胶体表面双电层的相互作用与电荷密度、离子强度、盐吸附的关系,扩散层重叠机制以及双电层作用对土壤表面性质和土壤酸化的影响。     

Soil acidification used as a management strategy to reduce nitrate losses from agricultural land

pH is known to be a primary regulator of nutrient cycling in soil. Increasing soil acidity in agricultural systems has the potential to slow down N cycling and reduce N losses from leaching thereby enhancing sustainability and reducing pollution. We conducted a field experiment to investigate the impact of acidity on N leaching in arable and grassland agricultural systems. The results showed that nitrate (NO₃⁻) concentrations in soil water were greater under arable than under grassland. Soil acidification significantly lowered NO₃⁻ concentrations in soil water over winter and spring under grassland, whilst in cereal plots a similar effect was only observed in spring. Our results suggest that soil acidification decreased nitrification causing an accumulation of NH₄⁺ which was not subject to leaching. Dissolved organic nitrogen (DON) concentrations in soil water were significantly greater under arable than grassland. Soil acidification lowered concentrations of DON in soil water, usually to a greater extent in grassland than in arable plots. It was concluded that it may be possible to use careful soil pH management as a tool to control NO₃⁻ leaching without compromising the quality of drainage water, and that this may be more effective on grassland than on arable crops.     

山东省土壤酸化特征及其影响因素分析

为弄清山东省土壤酸化状况,采用统计分析和空间分析方法,对山东省测土配方施肥项目数据进行分析,并与第2次全国土壤普查的部分数据作比较,分析山东省不同区域、不同土地利用类型、不同土类的土壤酸化状况。结果表明:1)山东省的酸化土壤面积为126.4万hm2,占全省土壤面积的8.13%,与第2次全国土壤普查相比,酸化面积增加了8.07%;2)山东省土壤p H值呈现自西向东、由北向南逐渐减小的趋势,酸化土壤集中分布在鲁东和鲁南地区的威海市、烟台市、日照市、青岛市和临沂市;3)不同土地利用类型中,园地中的茶园酸化程度较重,耕地酸化程度最轻;4)不同土类中,棕壤酸化程度最重,潮土酸化程度最轻。山东省土壤酸化呈现严重的趋势,其自然地理气候条件、不同土地利用方式以及施肥管理等是可能导致土壤酸化的主要原因。     

土壤加速酸化的主要农业驱动因素研究进展

土壤酸化是土壤质量退化的一个重要方面,农业活动对其有极其重要的驱动作用。本文从土壤酸化加速的农业主驱因素:化肥、作物及有机物料等方面阐述它们对土壤酸化的影响。认为化肥尤其是生理酸性肥料和含硫肥料的不合理施用加速土壤酸化,而氮肥的致酸除受氮素形态影响外,硝化作用及硝化产物的淋溶是重要的致酸原因,同时豆科作物的固氮致酸作用也不容忽视。作物通过选择性吸收盐基阳离子,通过秸秆和子粒转移出生产系统后,导致土壤盐基量减少,土壤表面交换性酸增加;作物根系呼吸、根系分泌物及土壤溶液中重碳酸盐的淋溶也引起土壤酸化;而秸秆和畜禽粪便对土壤酸化的影响除受土壤本身性质影响外,秸秆中的灰化碱含量、畜禽粪便中的碳及氮和盐分去向对酸化也有重要的影响。     

Long‐term acidification of farmland in northern Idaho and Eastern Washington

Abstract

In the past several years many scientists, consultants and growers in northern Idaho and eastern Washington have noticed a decline in the pH of agricultural soils. The purpose of this study was to compile and generate data for the determination of the causes, rate and magnitude of the pH decline in the region. Soil pH records from the past 40 years were collected from the soil testing laboratories at the University of Idaho and Washington State University. An intensive field pH survey was conducted in northern Idaho from 1982–84 and virgin soil samples were acidified under laboratory conditions.

Soils in northern Idaho and eastern Washington have undergone a rapid decline in pH in the past 25 years. These soils, which were near neutral in pH in their virgin state, have been acidified to the point that over 65% of the agricultural soils in the region have soil pH values less than 6.0. By 1984 over 45% of the agricultural soils in northern Idaho had pHs less than 5.6. This pH decline is attributed to the long‐term use of high rates of N fertilizers, as over 1250 kg N/ha have been applied to typical soils in the region since the virgin prairie sod was first broken for agricultural production. Seventy‐five percent of all N has been applied since 1960. Consequently, most soil acidification has occurred in the last 25 years. Field simulation in the laboratory was used to confirm the extent of soil acidification attributable to N fertilizer.     

江苏省苏南地区耕地利用变化特征及其对策

从耕地面积、土壤肥力和农业利用布局3个方面概述了苏南地区耕地资源利用现状,分析了耕地面积减少、土壤养分非均衡化、农田污染加剧、土壤酸化等耕地利用中的问题,提出了严格保护耕地数量、提高耕地基本农田质量、完善相关法律法规等耕地保护对策。     

Soil acidification and the importance of liming agricultural soils with particular reference to the United Kingdom

Soil acidification is caused by a number of factors including acidic precipitation and the deposition from the atmosphere of acidifying gases or particles, such as sulphur dioxide, ammonia and nitric acid. The most important causes of soil acidification on agricultural land, however, are the application of ammonium‐based fertilizers and urea, elemental S fertilizer and the growth of legumes. Acidification causes the loss of base cations, an increase in aluminium saturation and a decline in crop yields; severe acidification can cause nonreversible clay mineral dissolution and a reduction in cation exchange capacity, accompanied by structural deterioration. Soil acidity is ameliorated by applying lime or other acid‐neutralizing materials. ‘Liming’ also reduces N₂O emissions, but this is more than offset by CO₂ emissions from the lime as it neutralizes acidity. Because crop plants vary in their tolerance to acidity and plant nutrients have different optimal pH ranges, target soil pH values in the UK are set at 6.5 (5.8 in peaty soils) for cropped land and 6.0 (5.3 in peaty soils) for grassland. Agricultural lime products can be sold as ‘EC Fertiliser Liming Materials’ but, although vital for soil quality and agricultural production, liming tends to be strongly influenced by the economics of farming. Consequently, much less lime is being applied in the UK than required, and many arable and grassland soils are below optimum pH.     

不同种植年限酸化果园土壤微生物学性状的研究

土壤微生物学指标能够反映土壤质量,是敏感的土壤质量指标。本文以山东果园土壤急剧酸化为背景,研究了山东5个不同种植年限酸化果园(5a～30a)土壤pH值、土壤的微生物数量、土壤微生物量和酶活性的变化,分析果园土壤微生物学性状与土壤pH值的相关性。结果表明:随着种植年限的延长,除真菌、磷酸酶活性只在一定范围内呈现波动趋势外,土壤pH值与微生物数量,土壤微生物量、土壤酶活性呈现不同程度下降。其中酸化果园土壤pH值与微生物量碳、蔗糖酶、过氧化氢酶之间都存在着极显著相关,相关系数分别为0.92、0.97和0.94。土壤微生物数量、土壤微生物生物量、土壤酶活性之间也存在着某种关联,集中体现在土壤酶活性之间及与土壤微生物生物量之间。     

集约农业利用下红壤地区土壤肥力与环境质量变化及调控—江西省南昌市郊区和余江县案例研究

选择江西省南昌市郊区和余江县分别代表红壤地区集约化农业快速发展的大城市郊区和典型农区,研究集约农业利用下红壤地区土壤肥力与环境质量的变化特征与调控措施.结果表明,20多年来,以南昌市郊区为代表的城郊菜地的土壤有机质含量平均增加21.53%（一般农田的土壤有机质含量变化不大）,土壤速效磷含量增加13.15～18.86倍,土壤速效钾含量平均增加1.15～1.35倍;而土壤全氮含量增加不明显,土壤硝态氮的积累不多;以余江县为代表的传统农区,土壤酸化趋势明显,近90%的土壤有pH下降现象,平均下降达0.5个单位;同时部分农田土壤有一定程度的重金属污染.农业种植业结构调整、化肥用量的增加特别是磷钾肥的大量施用、以及畜禽粪肥的施用,是造成土壤养分富集和失衡、土壤酸化的重要原因.工业生产是造成农田土壤污染的主要原因.短期减量施肥、配合施用养分促进剂,以及通过施用缓释肥料提高肥料利用率,均可在一定程度上控制养分的过度富集与失衡; 适当施用石灰等碱性改良剂是防治土壤酸化的重要措施;而对于轻度污染土壤,可以通过施用化学改良剂（如石灰等）,或种植超积累植物而得到修复.     

鄱阳湖流域典型区限制水稻产量的土壤因素分析

影响作物生产的土壤因素会随着耕作管理措施的变化而改变,研究目前条件下影响作物生产的主要土壤因素并分析其变化的原因,可以为作物的生产和管理提供重要决策支撑。本文以江西省鄱阳湖流域进贤县作为典型研究区,在全县范围内布点采样分析,获取51组土壤属性数据和野外水稻测产数据,采用主成分分析法,用主成分表征研究区内主要土壤因子,并与水稻产量之间进行相关性分析,获得了影响水稻产量的主要因子。结果表明:钾素因子、物理结构因子与水稻产量之间达到显著相关水平,相关系数分别为0.325(P0.05)、0.411(P0.01),成为当前研究区内水稻产量的主要限制因子;淹水条件下,土壤酸化对水稻生产的影响并不明显,但其导致的钙、镁等盐基离子流失可影响作物产量;稻田排灌体系的完善可以减弱土壤潜育化作用对水稻生长的影响。     

Nutrient concentrations and acidity in ferralitic soil under perennial cropping, fallow and primary forest in central Amazonia

The long‐term productivity on the acidic, nutrient‐poor upland soils of central Amazonia depends to a large extent on the chemical soil fertility as influenced by vegetation type and management. We compared soil and soil solution data from permanent cropping, fallow and primary forest on a Xanthic Ferralsol in central Amazonia to evaluate changes of soil fertility following forest conversion, agricultural use at different intensities and setting aside agricultural land. The agricultural systems included a perennial polyculture at two fertilizer inputs and a monoculture plantation. Soil and soil solution were collected to 2 m depth, and the soil solution was monitored over 2 years. Both soil and soil solution data showed decreasing soil fertility in the sequence: monoculture and polyculture at large input, polyculture at small input, forest and fallow. The soil solution data were more sensitive to effects of systems and fertilizer inputs on subsoil fertility. Fractionation of the N in the soil solution showed a larger proportion of dissolved organic N in the N‐poor fallow soil than in the soil under forest and agriculture. The soil under fallow, forest and low‐input agriculture had larger exchangeable acidity than that under high‐input agriculture, but the Al concentrations in the soil solution were very small because there were few cations with which to exchange and less nitrification. In high‐input agriculture, pronounced acidification peaks in the topsoil solution followed fertilization. The comparison of soil and soil solution data explained why the spontaneous vegetation thrives at very large exchangeable acidity in these soils, whereas agricultural systems often depend on liming to reduce the concentration of toxic Al in the soil.