Potassium fertilisers

The results expected from the potassium fertiliser remediation strategy are consistent with international guidance on interventions to avoid dose in chronic exposure situations and, therefore, this strategy would provide a radiologically safe environment permitting early resettlement. 

The disadvantages of using urea are that some urea evaporates especially if there is no rain within 4 days of application. It cannot be blended with phosphate nor potassium fertilisers, and it is less suitable on chalky soils. It can cause damage to seedlings. It does not work if the soil is too cold. 

The quality or grade of potassium fertilisers is expressed as a percentage of... 

Table 20.5 Phosphorus and potassium fertiliser recommendations for grassland (kg/ha or K,0)... 

Potassium [7440-09-7] K, is the third, element ia the aLkaU metal series. The name designation for the element is derived from potash, a potassium mineral the symbol from the German name kalium, which comes from the Arabic qili, a plant. The ashes of these plants al qili) were the historical source of potash for preparing fertilisers (qv) or gun powder. Potassium ions, essential to plants and animals, play a key role in carbohydrate metaboHsm in plants. In animals, potassium ions promote glycolysis, Hpolysis, tissue respiration, and the synthesis of proteins (qv) and acetylcholine. Potassium ions are also beheved to function in regulating blood pressure. 

There are a considerable number of stable crystalline salts of the ammonium ion [14798-03-9] NH. Several are of commercial importance because of large scale consumption in fertiliser and industrial markets. The ammonium ion is about the same size as the potassium and mbidium ions, so these salts are often isomorphous and have similar solubiUty in water. Compounds in which the ammonium ion is combined with a large, uninegative anion are usually the most stable. Ammonium salts containing a small, highly charged anion generally dissociate easily into ammonia (qv) and the free acid (1). At about 300°C most simple ammonium salts volatilize with dissociation, for example... 

In hospitals, chemical analysis is widely used to assist in the diagnosis of illness and in monitoring the condition of patients. In farming, the nature and level of fertiliser application is based upon information obtained by analysis of the soil to determine its content of the essential plant nutrients, nitrogen, phosphorus and potassium, and of the trace elements which are necessary for healthy plant growth. 

During manufacture of 26/16/10 N/P/K fertiliser by ammoniation of nitric-phosphoric acid mixtures, followed by concentration, addition of potassium sulfate, then granulation at up to 250°C, the possibility of a thermal explosion exists. Kinetic studies showed that 240°C appears to be a safe granulation temperature, but that changes in the composition and pH of the mixture may decrease this critical temperature. 

Weed competition for water and nutrients can have similar effects on fruit quality as described above for fertilisation. For example, if weed competition is completely prevented by chemosynthetic herbicides in conventional production, this can lead to excess supply of certain mineral nutrients, in particular nitrogen and potassium, which in turn results in reduced sensory quality and shelf-life (Section 16.2.2). On the other hand, excessive weed competition, in particular, during the pre-bloom phase and the end of the first shoot growth period (Gut and Weibel, 2005), can induce nutrient and/or water deficiency and a risk of quality loss. 

Plant nutrients are interesting not only in connection with the yields and the fertilisation, but also with regard to environmental effects of energy conversion processes. Thus, they are regulated in various standards. Nitrogen (N), phosphorous (P) and potassium (K), as well as sulphur (S) and chlorine (Cl) are the most important environmentally relevant macronutrient and micronutrient elements. 

Sewage sludge contains significant concentrations of nutrients, particularly N and phosphorus and is recognised as having considerable potential as a fertiliser material and soil conditioner. Concentrations of nutrients vary considerably between sludges. Sommers [4], reported ranges of <0.1-17-6% for total N, <0.1-14.3% for total P, and 0.02-2.64% for total potassium. 

Self-sustaining thermal decomposition of NPK fertilisers is apparently possible if crystalline potassium nitrate is present from a exchange reaction of ammonium nitrate [1], Almost pure fertiliser grades of ammonium nitrate are legally restricted in some countries because of its instability [2],... 

Schwer, E.W. and Conan, H.R. (1950) Fertiliser analysis. The determination of potassium. In Joint Symposium on Fertiliser Analysis. Proceedings No. 62. 

Eppendorfer, W. H., Bille, S. W. (1996). Free and total amino acid composition of edible parts of beans, kale, spinach, cauliflower and potatoes as influenced by nitrogen fertilisation and phosphorus and potassium deficiency. Journal ofthe Science of Food and Agriculture, 71,449M58. 

Y. Araten, A. Baniel, and R. Blumberg, Potassium Nitrate, Proceedings No. 99, The Fertiliser Society, Alembic House, London, Oct. 1967. 

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. 

NH4N03), ammonium phosphate ((NH4)3P04) and potassium chloride (KC1) in varying proportions (Figure 11.19). Fertilisers have an important role in the nitrogen cycle (see below). 

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. 

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