32 MANURES 



Sulphate of potash usually contains about. 50% of potash, 

 and is considered to be the cheapest and best form of applying, 

 potash to the soil. In orchards it may be applied at the rate of 

 about 1 Ib. per tree, and to Tea plants about 1 12 Ib. per acre may 

 be given, as with buried primings. 



Kainit. A compound of sulphate of potash and magnesia, 

 now much used as a potash manure. It is imported from Germany, 

 and usually contains 12 to 14 per cent, of potash, and about 35 per 

 cent, of common salt. 



Muriate of potash. Also a product of German potash mines, 

 said to contain about 50 to 60% of actual potash. 



Superphosphate. This is perhaps the most important and 

 universally used form of phosphatic manures. It is made by treat- 

 ing rock-phosphates, bones, etc., with sulphuric acid, afterwards 

 drying the product. As usually prepared, it should contain about 

 17% phosphoric acid soluble in water. A form known as "Con- 

 centrated Superphosphate" is imported which contains about 44% 

 soluble phosphoric acid. 



Basic slag, Basic cinder, or Thomas' phosphate is a by- 

 product obtained in the manufacture of steel. Iron ores contain 

 irregular quantities of phosphorus, and the object of the steel- 

 maker is to get rid of all the phosphorus in the iron. To effect this the 

 iron is melted in contact with limestone, which extracts the phos- 

 phorus and forms a slag. This, when ground to a hue powder, 

 forms what is known as basic slag, which may vary very consider- 

 ably in quality, though usually it contains 30 % to 40 % phosphate. 

 Basic slag has grown in favour as a form of manure in Ceylon, 

 more especially for applying with buried Tea primings or green- 

 manure ; in this way it may be applied at the rate of about 3 to 5 

 cwt. per acre. For fruit trees, roses, etc., it may be applied with 

 good results at the rate of 4 to 6 ox. per square yard. 



Phosphate of lime. All organic manures, and some kinds of 

 chalk and marl, contain phosphate of lime. This is also found in 

 nearly all plants, and, on account of its supplying phosphoric acid, 

 constitutes a valuable addition to soils. Phosphatic manures are 

 noted for stimulating plants into vigorous growth, thereby render- 

 ing them better able to assimilate the potash contained in the soil. 



Chilinit is described as a new fertiliser, composed of the 

 fertilising ingredients in the waste from sugar refineries. u Nitri- 

 fying bacteria are cultivated in a portion of the molasses, which is 



