Acidification nitrogen source

Stumpe JM, Vlek PEG. 1991. Acidification induced by different nitrogen sources in columns of selected tropical soils. Soil Sci Soc Am J55(l) 145-151. 

Preparation. According to Plattner and Clauson-Kass, lycomarasmin is isolated as follows Fusarium lycopersici is cultured in a glucose-mineral medium whose nitrogen source is ammonium nitrate. After 2 to 4 months, the maximum concentration of lycomarasmin in the medium (as measured by blighting power for the tomato) is attained. The mycelium is removed by filtration, sulfate, and phosphate are precipitated by baryta, and ammonia is removed by vacuum distillation. The active substance remains in solution from which, on acidification with HCl, and addition of ethanol, lycomarasmin crystallizes in fine needles. 

Acid atmospheric waters can reduce the pH of surface waters with low neutralization capacity. For example, in Scandinavian lakes and rivers, acidification caused by acid atmospheric precipitations results in the killing of fish species, trout and salmon. Apart from the reduced abundance of fish, acid atmospheric waters also unfavourably affect the soil composition (soil becomes poor in cations, replaced by hydrogen ions), as well as the growth of plants. They also cause significant corrosion of concrete, mortar, iron and other metals. Because of this property, low mineralization and irregularity of precipitation, atmospheric waters are very seldom used directly for water supplies. In some cases atmospheric waters can be an important source of nitrogen compounds for agriculture. 

In intensively cultivated areas, soil acidification from the nitrification process, following application of nitrogen fertilisers, far outweighs any effect from acid precipitation -Section 5.4.3. The potential loss of nutrients caused by this process are made up by application of the other fertilisers (Section 5.5). Only in the poor soils of pine and spruce forests is the acidification caused by acid precipitation substantial in relation to other sources. It may also be seen that forestry practices themselves can be a significant cause of soil acidification - Section 5.4.4. However, an important distinction should be made between organic acids formed from natural acidification processes, which are weak acids, and acidification... 

As well as the sulfur cyde, there are other cycles in nature water, nitrogen, phosphorus and carbon. Man has influenced them all, but the sulfur cycle is the most disturbed among aU these cydic processes. Fossil fuels are burned in order to warm up houses and to provide cars, power stations and industries with energy. Then the sulfur that was built into coal, oil and natural gas, millions of years ago, is set free. It is transported as sulfur dioxide to the atmosphere, the SO content of which has increased considerably compared to the equilibrium content of the natural cyde. The acid gas is transported by the winds over the continents, and, long distances from a specific source, people experience a rain of sulfuric acid . This acid rain not only attacks the needles and leaves of trees but also damages the roots of plants. In acidified lakes the ability of fish to reproduce is disturbed. If acidification is not neutralized by liming, metal ions may be leached from rocks and damage animal life. 

Nitrogen losses from organic sources can be minimised by application in the spring and summer rather than the autumn and winter, and such practices as soil injection will reduce volatilisation losses. Nitrification inhibitors have been investigated but their effects are often variable, and their widespread use is precluded by high costs. Dilution, acidification and separation are also techniques which have been investigated and which show some promise. 

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