ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00639.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Inputs of acidity to the ground arise through two distinct routes: wet deposition which includes all acidity deposited in rain and snow and dry deposition, the direct sorption of SO2, NO2or HNO3gases by vegetation or soil surfaces. The acidity from dry deposition of SO2and NO2is created during the oxidation of deposited SO2and NO2to SO24and NO3−respectively. The areas of Britain experiencing the largest wet deposition of acidity are the high rainfall areas of the west and north, in particular the west central highlands of Scotland, Galloway and Cumbria where inputs exceed 1 kp H+ha−1annually. Wet deposited acidity in the east coast regions of Britain is in the range 0.3–0.6 kg H+ha−1a−1. Monitoring data for rainfall acidity at rural sites throughout northern Britain show a decline in deposited acidity of about 50% during the last six years. Dry deposition is largest in the industrial midlands and southeast England and in the central lowlands of Scotland, where concentrations of SO2are largest. In these regions the dry deposition of SO2following oxidation may lead to acid inputs approaching 3 kg H+ha−1a−1and greatly exceeding w

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00640.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Rainfall has become less acid at Rothamsted and Saxmundham over the period 1969–83. The pH of rain at these two sites has increased from 4.4–4.6 to about 4.8–4.9; at Woburn it has remained approximately constant at 4.4–4.6. Amounts of NH4‐N and NO3‐N deposited at present are 10–15 and 5–10 kg ha−1a−1respectively. They have been increasing at Rothamsted and Woburn. Some 50–60 kg ha−1a−1of Cl and 25–35 kg ha−1a−1of SO4‐S are presently deposited. Deposition of non‐sea Cl and SO4‐S has been increasing markedly at all three sites. Non‐sea salts comprise 35% of the total salt deposition near the coast at Saxmundh

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00641.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00642.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Natural acidification processes result in increasing solubility of aluminium as soils become more acid. Exchangeable aluminium provides a large reserve that can be mobilized by percolating acids or salts, with solution pH determining the upper limit of its solubility. Aluminium can also be mobilized within soils and into drainage waters in soluble complexes with silica or fluoride, and in organically complexed forms.

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00643.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00644.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Data on lime loss and soil acidification obtained from a range of ADAS experiments are reviewed. The trials, which include drainage and lysimeter studies and long‐term liming, manuring and soil management experiments, indicate a wide range of annual lime losses, with maximum rates in excess of 1000 kg ha−1Ca

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00645.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.Survey information on the use of lime in England and Wales between 1974 and 1983 shows year‐to‐year fluctutions but no marked trend. Areas limed per year are compared for different types of region and cropping, and estimates given of the percentages of agricultural soils by pH according to rotation type. There was no general change in soil acidity between 1969–73 and 1974–78 but recent data show some reductions in grass

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00646.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.The pH of soil surface horizons in Wales ranges from 3.5 to 7.5 and is significantly higher on agricultural land than under either rough grazing, unenclosed grassland or woodland. Sufficient information exists to map broad classes of soil pH. Rough grazing and woodland sites are concentrated on soil types which are naturally very acid. In Wales, such soils are found on the main mountain ranges and show up clearly on the map of pH. Their acidity is the result of an interrelationship between soil, climate and vegetation. However, afforestation, particularly with coniferous species, appears to lower the pH of the underlying soil. There is a trend in agricultural soils towards lower pH under a moister climate.

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00647.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract.The impact of isolated trees and natural forest vegetation on soil acidity is discussed. There is a considerable variation in impact between species on similar soils and between sites for any given species. The effect of coniferous plantations on soil acidity is reviewed and the causes of any increased acidity discussed. Crop species, initial soil conditions, silvicultural practices and the proportion of the tree removed at felling are all important factors influencing the long‐term impact of plantations on soil acidit

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1985.tb00648.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY