Peaty acids

Some of the worst corrosive effects in soft waters are attributed to a rather wide group of organic acids abstracted from peat and mosses, sometimes called peaty acids. Such waters have low pH values and are often discoloured. They affect ferrous metals appreciably and also attack lead and... 

Camellias require a moist, peaty, acidic soil w ell-enriched with organic matter. Set out as bare-root plants in partial shade. A thick... 

Cinders and acid peaty soils are obviously among the soils most corrosive toward copper. There is, however, no direct relationship between the rate of corrosion and any single feature of the soil composition or constitution". For instance, in the American tests corrosion in several soils with either low pH or high conductivity was not particularly severe, while the British tests show that high chloride or sulphate contents are not necessarily harmful. 

While phosphorus export from agricultural systems is usually dominated by surface runoff, important exceptions occur in sandy, acid organic, or peaty soils that have low phosphorus adsorption capacities and in soils where the preferential flow of water can occur rapidly through macropores (Sharpley et al., 1998 Sims et al., 1998). Soils that allow substantial subsurface exports of dissolved phosphorus are common on parts of the Atlantic coastal plain and Honda, and are thus important to consider in the management of coastal eutrophication in these regions. 

In data assembled by Greenland (1997), the mean level of organic carbon in the topsoils of wetland rice soils from across tropical Asia was 2%, and after excluding acid peaty soils the mean was 1 %. This compares with a range of 1.27-1.81 % for Oxisols and Ultisols of the Cerrado region of Brazil (Sanchez,... 

Peaty soil This forms where wet, acidic conditions prevent full decomposition of organic matter. Peaty soil is black and feels spongy, and cannot be rolled into a ball. It is rich in organic matter and very easy to work, but can get very dry in summer and may be very acidic (see Soil chemistry,p.30). 

Hay has been analysed by NIR for crude protein, acid detergent fibre, dry matter, lignin and IVDMD, rapeseed for oil and water and spring field beans for N to name but a few applications. Most macroinorganic constituents of peaty soil can be determined, and moulds have been measured in hay, tall fescue and barley (Malley and Nilsson, 1995). A short bibliography is given below. 

Natural waters in the acid range can arise by absorption of acidic atmospheric gases (Chap. 2) or by the accumulation of humic acids on percolation through peaty soils. They have the potential to mobilize elements of the rocks and soils, through which they flow. In limestone, dolomites, and similar rock formations, calcium, magnesium, and other elements may be dissolved, in the process increasing the pH. At the same time, these processes raise the hardness of water (e.g., Eqs. 4.22 and 4.23). 

Tjeukemeer is an alkaline, humic-substance-rich, polder lake in the northern Netherlands (De Haan et al., 1979, 1981b). In winter the lake receives hu-Tiic-substance-rich water from the surrounding peaty polders. In summer, evaporation losses are compensated for by input of humic-substance-poor vater from the Ijsselmeer. De Haan (1972a) demonstrated that the fulvic -cids from Tjeukemeer could be separated into three different molecular -eight fractions. The relative proportion of each fraction appeared to de-rend on the type of water present. In winter, about 70% of the fulvic acid... 

The mobility of Mn defies classification because it is extremely sensitive to soil conditions (acidity, wetness, biological activity, etc.). Toxicity to plants is most likely in waterlogged soils or acid soils with low humus content. Deficiency is most often found in soils that are saUne and alkaline, calcareous, peaty, coarse textured, or acid leached. 

Molybdenum is most commonly deficient in coarse-textured acid soils and low-humus soils. Plant toxicity is associated with poor drainage and alkaline, calcareous, clayey, or peaty soils. 

Interestingly, the relations between soil pH and N supply found along the short transect at Betsele are very much the same as those proposed by Read (1986 1991) as typical for long latitudinal and altitudinal gradients from polar/Alpine conditions through temperate coniferous forests and nemoral deciduous forests to dry and warm temperate steppe conditions. Read proposed that under cold and wet conditions, decomposition of organic matter would be slow and incomplete and result in the formation of acid, peaty soils or thick mor-layers with slow mineralization of organic... 

In the nineteenth century, lead was still widely used for conducting water and in cisterns, but its use for such purposes has now become unpopular because of the toxicity hazard associated with the enhancement of lead levels in drinking water. The extent to which lead is dissolved from lead pipes is increased at acidic pH levels and water drawn from peaty areas, or containing a high level of carbonic acid can contain relatively high levels. Lead pipes are therefore particularly unsuitable for the storage or conveyance of acid acoholic beverages, such as cider or wine, which may become seriously contaminated. 

Humic earth results from the decomposition of organic matter, particularly cellulose from dead plants. The organic phase contains humic acids, allomelanins with complex phenolic macro-molecular structure. Humic substances fall between plants and geological materials (coals and petroleum). Degraded organic matter when released into the environment will form relatively soluble fulvic acids which will condense to form humic acids and then humins with lower solubilties. Humic earths are transitional between the low grade coal lignite (. v.) and peaty soils. 

DEHAAN H., piRLEMARK G. and DEBOER T. 1983. Effect of pH on molecular weight and size of fulvic acids in drainage water from peaty grassland in NW Netherlands. Plant and Soil, 75, 63-73. 

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