Fertilisers, Potash

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. 

Tennant also investigated the action of fused nitre on gold and platinum, both of which he found to be corroded. He found that magnesian limestone acts prejudicially when used as a fertiliser. He described a method of producing a double distillation with the same heat, and a simple method of preparing potassium by heating caustic potash and iron in a tube and condensing the vapour in a vessel in a cooler part of the tube. He described native boric acid of the Lipari Islands. ... 

Available nutrients. This is the level of phosphate, potash and magnesium and it is indicated by index ratings 0-9. A deficiency level is indicated by 0 and an excessively high level by 9 (never reached imder field conditions). An index of 2 and 3 is satisfactory for farm crops. As indices drop below 2 more fertiliser is recormnended so that the index will go up over a period of time, and as they get above 2 or 3 the recommendations decrease until, at index 4 and over, no applications of phosphorus, potassiirm or magnesium are required. 

Might cause crops to ripen too early and so reduce yield if not balanced with nitrogen and potash fertilisers... 

The cost of plant food per kilogram can be calculated from the cost of fertilisers which contain only one plant food such as nitrogen in ammonium nitrate, phosphate in triple superphosphate, and potash in muriate of potash. 

These are also known as potash fertilisers, which is short for potassium ash. 

Muriate of potash (potassium chloride). As now sold, it usually contains 60% K O. It is the most common source of potash for farm use and is also the main potash ingredient for compound fertilisers containing potassium. As a straight fertiliser it is normally granulated, but some is marketed in a powdered form. KCl is found in vast quantities all over the world and is mined from rock deposits left by dried-up oceans. It is nearly always found in conjunction with NaCl and the two are separated by a flotation process. 

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. 

Combine drills. Fertiliser and seed (e.g. cereals) from separate hoppers are fed down the same or an adjoining spout. A star-wheel feed mechanism is normally used for the fertiliser and this usually produces a dollop effect along the rows. In soils low in phosphate and potash, this method of placement of the fertiliser is much more efficient than broadcasting and can require less fertiliser to be used per hectare, e.g. P and K in potatoes. It is known as combine drilling and is sometimes referred to as contact placement . Because of possible scorch, combine drilling should only be used for cereal crops. 

Kale. As this crop (like maize) is not normally sown until late April or May, there is usually a good opportunity to apply slurry from the wirrter accumulatioa There should be no need for any phosphate and potash fertihser following a slurry application, although extra nitrogen will normally be necessary. This fertiliser recommendation also applies to forage maize. 

A well-drained soil with a pH of over 6 is essential and the crop is best sown after cereals or fallow. A rotation of one year in five or six is recommended to reduce the risk of infection from Sclerotinia sclerotiomm. Fertilisers used are 25-50 kg/ha of nitrogen, and 40-60 kg/ha of phosphate and potash which should be applied to the seedbed as a compound. Too much nitrogen can cause lodging, can favom disease development, delay matmity and lower seed oil content. Sunflowers are sensitive to boron deficiency. 

Less nitrogen is needed in wetter areas, although exactly how much is used wiU depend on the soil nitrogen supply status. More phosphate may be needed on heavier soils, but this will a in depend on the soil phosphate index if the fertiliser is placed 5-10 cm below the seed, the phosphate can be reduced. Potash is important, but savings can be made by using organic manures. As with fodder... 

Crop agronomy and fertiliser inputs will be much the same as for a livestock based unit, except that the absence of any return of organic manures necessitates the substantial use of both nitrogen and potash fertilisers on grass and mainly potash fertiliser on lucerne. In the latter case potash (K O) application can be as much as 375 kg/ha in order to replace that removed by the crop. 

This paper presents equations of compressibility derived from the modulus of volume transformation. These new equations are compared to an empirical equation used by Johanson in the theory of roll press design. The equations were used to fit data from compressibility measurements for potash, fertiliser and salt measured in a die press and roll press. It has been shown the new equations fit the measured curves more accurately than the equation used by Johanson. Consequently, utilization of these equations in the roll press design can provide us with more accurate results. Question of possible utilization of compressibility parameters from a die pressing in the theory of roll press design is also addressed. 

Measurements were done for three materials such as potash, fertiliser and salt. It has been shown the new equations of compressibility correlate the measured values in die press better than Johanson s equation (fig. 3-5). For roll press there was no substantial difference among the equations. Noteworthy is fact the new equations are derived fiom material property called the modulus of volume transformation whereas Johanson equation is of empirical nature. But it must be pointed out the equations derived from linear and power moduluses of volume transformation are not recommended for utilization in the theory of roll press design. On contrary one parameter s equation (10) derived from the simple linear modulus of volume transformation is suitable for inclusion into the theory of roll press design. Figures 7-9 reveal the parameters of compressibility from die press can be used in roll press design within acceptable error however for more accurate results measurements in a roll press are necessary. 

The method used in the Fertilisers and Feeding Stuffs Regulations (1960), for the determination of potash as perchlorate in guanos and mixed fertilisers, will give generally concordant results. It is summarised below ... 

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