Sodium fertilisers

Sodium is not an essential plant food for the majority of crops. However, for some, notably sugar beet and similar crops, it is highly beneficial and should replace at least half the potash requirements. The adverse effects it has on weak structured soils such as the Lincolnshire silts should be noted but, on other soils, this should not be a problem. Agricultural salt (sodium chloride, 37% Na) is the main sodium fertiliser used. It is now available in a granular form. 

Sodium nitrate is used as a fertiliser and in a number of industrial processes. In the period from 1880—1910 it accounted for 60% of the world fertiliser nitrogen production. In the 1990s sodium nitrate accounts for 0.1% of the world fertiliser nitrogen production, and is used for some specific crops and soil conditions. This decline has resulted from an enormous growth in fertiliser manufacture and an increased use of less expensive nitrogen fertilisers (qv) produced from synthetic ammonia (qv), such as urea (qv), ammonium nitrate, ammonium phosphates, ammonium sulfate, and ammonia itself (see Ammonium compounds). The commercial production of synthetic ammonia began in 1921, soon after the end of World War I. The main industrial market for sodium nitrate was at first the manufacture of nitric acid (qv) and explosives (see Explosives and propellants). As of the mid-1990s sodium nitrate was used in the production of some explosives and in a number of industrial areas. 

In addition to a continued increase in the number of use patents in these fields, a new use of xanthates as inhibitors of fertiliser nitrogen transformation in soil has been reported, as well as the use of certain metal xanthates as color developers for image-recording materials (113,114) (see Fertilizers Color photography). For several years, sodium isopropyl xanthate was used as an intermediate in the manufacture of saccharin (see... 

Salt apphed as equal parts of unionised sodium chloride and calcium chloride at 20 g total per L for 1 h, three times a week, has also been used to control fungal infections on eggs. The salt combination is first appHed one day after fertilisation to the first pick of eggs. These compounds are categorized as generally recognized as safe (GRAS). 

Carbon dioxide gas is used to make urea (used as a fertiliser and in automobile systems and medicine), methanol, inorganic and organic carbonates, polyurethanes and sodium salicylate. Carbon dioxide is combined with epoxides to create plastics and polymers. 

Several methods of carbon dioxide production are in commercial use. These include the reaction between sulphuric acid and sodium bicarbonate, the combustion of fuel oil, the extraction of carbon dioxide from the flue gas of a boiler or similar heating facility, the distillation of alcohol and the fermentation of beer carbon dioxide is also a byproduct of fertiliser manufacture. Following manufacture the gas must be cleaned to ensure it is free from impurities and is fit for purpose. Two typical processes are described below. 

To determine the alkalies, another 200 c.c. of the liquid are evaporated to dryness, the residue being gently calcined and taken up in water and hydrochloric acid, and the non-alkali metals eliminated by means of ammonia and ammonium carbonate.1 The filtrate is evaporated to dryness with a little sulphuric acid and the residue heated to expel the ammonium salts and then weighed this gives the sodium and potassium sulphates together. If required, the two metals may be determined separately (see Fertilisers, Vol. I, pp. 124 and 135). 

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. 

ADAS, the advisory service for farmers in England and Wales, has adopted a method of P-extraction from soil using a sodium hydrogen carbonate solution. This extracts the P in the soil solution and the P that is easily desorbed from soil particles. By correlation of this chemical extraction method with extensive field trials of fertiliser response on different soil types, the advisory services are able to make fertiliser recommendations for farmers. 

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. 

It is a fact of modern society that many ordinary items of everyday use are obtained from complex chemical processes. Life-saving drugs, capsules and tablets, as well as perfumes, are derived from coal. From crude oil and petroleum gases, we obtain fertilisers, plastics, synthetic rubbers, pesticides, detergents, fabrics and coatings and paints. From seawater we can produce vital heavy chemicals including caustic soda, sodium chloride, sodium hydroxide, hydrochloric acid and so on. 

It was already recognised by the turn of the century that high doses of fertilisers, such as Chile salpetre (NaNOj), ammonium sulfate, calciiun cyanamide and kainite (KCl, MgSO SHjO) exhibit herbicidal action. Remy and Vasters (1914) were the first to observe the phenomenon of synergism in combined preparations. They established that 10% of kainite mixed with calcium cyanamide was more active than double doses of the single components used alone. A similar enhancement of action was observed by Bolley (1901) in the case of mixtures of copper sulfate and sodium arsenite. 

The liberated acid was titrated directly with 0.100 mol dm aqueous sodium hydroxide. The average volume required was 28.0 cml Calculate the percentage of ammonium sulphate in the fertiliser. [5] b In a second determination of the ammonium ion content, the same mass of fertiliser (i.e. 3.80 g) was treated with excess sodium hydroxide and heated. The ammonia liberated was passed into a known excess of hydrochloric acid. The unreacted hydrochloric acid was then titrated with standard aqueous sodium hydroxide. 

A fertiliser contains ammonium sulphate and potassium sulphate. A sample of 0.225 g of fertiliser was warmed with sodium hydroxide solution. The ammonia evolved required 15.7 cm of O.lOOmoldm" hydrochloric acid for neutralisation. Calculate the percentage of ammonium sulphate in the sample. 

In heterogeneous systems where several materials are present the existence and variability of these substances can be determined by the application of the phase rules. For the Ammonia Laboratory the existence of phases was especially important to the chemistry of fertilisers, which were often mixtures of various salts. In September 1920, Ernst JSnecke, then professor at the Hannover Technische Hochschule, joined the staff of the Ammonia Laboratory to study the phenomenon from its theoretical side. He began with investigations on ammonium sulphate and nitrate, and the sodium chloride/ammonium nitrate system. His group members (in 1922 four scientists) did more technical work in cement and salt chemistry. In Germany, theoretical work on the existence of phases did not play a major role at the universities. With the work of Janecke, I.G. Farben had access to the theoretical underpinning of the important fertiliser business. Janecke retired in 1935. ... 

Boron compounds are also used as food preservatives, and boron compounds such as sodium octaborate are used to fireproof fabrics. Boric acid is also used as an insecticide, in particular for ants and cockroaches in the home. Compounds of borate are used in many other applications (e.g., as fertilisers, in face powders to add a lustre and a silky feel, and so on). 

The commercial production of orthophosphates and polyphosphates, particularly the sodium, ammonium and calcium salts, together with phosphoric acid, greatly exceeds that of aU other compounds of phosphorus. The lion s share of these is used by the fertiliser industry, but detergents, animal foodstuffs, metal treatments and human food products are also major consumers. 

Apart from fertiliser ammonium phosphates, these salts, usually more expensive than those of sodium, are all produced commercially, but in much smaller quantities than the latter. 

Sodium nitrate (16% N, 26% Na). This fertiliser is obtained from natural deposits in Chile and is itsually rrrarketed as moisture-resistant granules. The nitrogen is readily available and the sodium is of value to some market garden crops. It is expensive and is not widely itsed. 

Excess nitrogen, potassium and sodium also leads to higher levels of impurities in the sugar. This makes the sugar more difficult and expensive to extract in the factory. This is now one of the measured factors determining price so it is important that growers tailor their fertiliser applications to the crop requirements and take into account the nutrient contribution from any organic fertiliser applied in the form of slurry or manure. 

BS 6070-0 1981 (2005) Methods of Sampling and Test for Sodium Carbonate for Industrial Use - General introduction and Determination of Pouring Density BS 5551 Part 3, Section 3.1 (1993). Replaced by BS EN 11236 1995 Fertilisers. Physical Properties Method for the Determination of Bulk Density (Loose)... 

Owing to low levels of selenium in the blood serum of the population of Finland, at the beginning of the 1980s it was decided to increase the selenium content in food crops by the addition of sodium selenate to the fertilisers used (the doses were 6-16 mg of selenium per kg of fertiliser). In a few years (from 1984-1986), the content of selenium in important crops and livestock products had increased. For example, wheat selenium content increased from 0.01 to 0.23, in potatoes from <0.002 to 0.02, in milk from 0.008 to 0.03 and in e s from 0.16 to 0.31 mg/kg. The average daily dose of dietary selenium increased to about 90 pg, and the selenium concentration in breast milk increased from 0.007 to 0.015 mg/kg. 

Chemical reactions can also cause the release of oxygen, particularly chemicals such as ammonium nitrate (fertilisers), sodium chlorate (pesticides), hydrogen peroxide (water treatment, hair care) and chromate (variety of Industrial processes). 

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