Artificial fertilisers

The organic farmer needs all the farmyard manure that his animals produce it is a valuable commodity for maintaining the fertility of his land, it is free and he cannot use most of the faster acting artificial fertilisers. 

In Switzerland, it was found that over a period of 6 years, the capacity of the soil in the plots fertilised with organic cattle manure to supply N to plants was greatly increased compared to soils which had been fertilised with artificial fertilisers (Langmeier, et al., 2000). 

Some of the ammonia produced by the Haber process is used to produce nitric acid. If ammonia is then reacted with the nitric acid, we have the basic reaction for the production of many artificial fertilisers. The use of artificial fertilisers is essential if farmers are to produce sufficient crops to feed the ever-increasing world population. Crops remove nutrients from the soil as they grow these include nitrogen, phosphorus and potassium. Artificial fertilisers are added to the soil to replace these nutrients and others, such as calcium, magnesium, sodium, sulfur, copper and iron. Examples of nitrogenous fertilisers (those which contain nitrogen) are shown in Table 11.7. 

Artificial fertilisers can also make fertile land which was once unable to support crop growth. The fertilisers which add the three main nutrients (N, P and K) are called NPK fertilisers. They contain ammonium nitrate... 

Farmers often need to add substances containing these nitrates. Such substances include farmyard manure and artificial fertilisers. One of the most commonly used artificial fertilisers is ammonium nitrate, which as you saw earlier is made from ammonia gas and nitric acid, both nitrogen-containing compounds. 

Water is very good at dissolving substances. Thus, it is very unusual to find really pure water on this planet. As water falls through the atmosphere, on to and then through the surface of the Earth, it dissolves a tremendous variety of substances. Chemical fertilisers washed off surrounding land will add nitrate ions (N03 ) and phosphate ions (PC)43 ) to the water, owing to the use of artificial fertilisers such as ammonium nitrate and ammonium phosphate. 

Artificial fertiliser A substance added to soil to increase the amount of elements such as nitrogen, potassium and phosphorus. This enables crops grown in the soil to grow more healthily and to produce higher yields. 

The chemical exploitation of bones thus led by a gradual transition to the artificial fertiliser or mineral phosphate industry which will now be described. 

Parrish and Ogilvie, Artificial Fertilisers, Benn, London, 1927. 

This calcium cyanamide has been found to be a valuable manure, and, containing as it does some 20 per cent, of available nitrogen against only 15 or 16 per cent, of sodium nitrate, it is now being made on an increasing scale for the manufacture of artificial fertilisers. 

Organic EARMING A set of agricultural practices in which no artificial fertilisers, hormones, pesticides or herbicides are used. Organic farming is increasingly popular in developed countries as consumers become more concerned over the potential health hazards of chemical residues in food. Boxes 1.1 and 1.2 (pp. 3-5) provide a more detailed definition. 

Macronutrients include N, K, PO3 and lime and are usually applied to the soil as natural or artificial fertilisers. The effects of additional fertilisers on medicinal plant productivity is generally beneficial, but scientific results have often revealed contradictory results and each plant must be investigated separately to determine the optimum level and frequency of fertiliser application. 

Up to World War 1 most industrial countries experienced a rapid increase in the production of sulphuric acid. This was a basic input product for the manufacture of traditional industries (such as textiles, iron and steel), as well as the newer heavy chemicals (oil refining, artificial fertilisers, and explosives) and the emerging fine chemicals (such as synthetic dyes). The strongest reasons for the early rise of this industry in Spain are the abundance of raw materials (sea salt and pyrites) and the existence of a consumer industry (textiles). The development of the acid industry was, however, difficult and slow in the previous century. The story of the pioneer enterprise, Cros, founded by a native of southern France in the surroundings of Barcelona in the... 

Nitrifications in soils where artificial fertilisation has taken place supplies the large majority of H+ input to soils. No fertilisation of forest soils assumed. 

Artificial fertilisation is systematically used on salmonids genetic improvement programs, even if some also rely on mass spawning. Instead, the latter technique is the most popular for species characterised by difficulties in fully mastering the artificial fertilisation like the Atlantic cod, the European seabass, the gilthead seabream and the common sole. 

MORI K, UEYANAGi s and NISHIKAWA Y (1971) The development of artificially fertilised and reared larvae of the yellowfln tuna, Thunnus albacares. Bulletin of The Far Seas Fisheries Research Laboratory, 5,219-232. 

Nitrogen compounds These also arise from both natural and synthetic sources. Thus ammonia is formed in the atmosphere during electrical storms, but increases in the ammonium ion concentration in rainfall over Europe in recent years are attributed to increased use of artificial fertilisers. Ammonium compounds in solution may increase the wettability of a metal and the action of ammonia and its compounds in causing season cracking , a type of stress-corrosion cracking of cold-worked brass, is well documented. 

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