185 



salt, which in the Eastern districts of this State, particularly where 

 the land is in places more or less permeated with saline matters, 

 could certainly be dispensed with. It is more valuable in light 

 loam than in heavier soils, which it makes more sticky. A fair 

 dressing per acre would be from 3 to 6cwt., mixed with other fer- 

 tilisers, and worked into the soil by means of the plough or the 

 digging harrows. 



Sulphate of Potash, which is the chief potash salt in kainit, is 

 also sold in a more concentrated form than in that crude salt, and 

 if found in commerce with a percentage of 50 to 54 per cent, of 

 potash, or more than four times the amount per cent, found in 

 kainit. Although its price is considerably higher than that of 

 kainit, at the same time, growers far inland will find it more 

 advantageous wherever freight and cartage is a consideration, the 

 fertiliser being four times more concentrated ; Icwt. per acre forms 

 a good dressing, in conjunction with other manures. 



Chloride, or Muriate of Potash, is the most soluble of the various 

 salts of potash, and when purified contains as much as 63 per cent, 

 of potash or 80 per cent, muriate of potash. It is obtained as a 

 by-product in the manufacture of chlorate of potash, in the 

 purification of nitre and other manufactures. Its use, however, is 

 harmful on certain crops, as in the case of sugar beets, in which 

 it lessens the percentage of crystallisable sugar, while potatoes are 

 rendered waxy, and the tobacco leaves are deteriorated in vulue ; in 

 the soil it is, besides, apt to give rise to the formation of common 

 salt, while the sulphate gives rise to the formation of gypsum, which, 

 in saline soils, is especially of value. 



In soils it occurs in quantities ranging from '01 to 2 per cent., 

 equivalent to 3501bs. to 70,0001bs. per acre taken to a depth of 1ft. ; 

 it is derived from the weathering of minerals containing it as an 

 ingredient, and chiefly from felspars, one of the constituents of 

 granite. It may be said that a soil showing '03 per cent, of potash 

 on analysis does not usually need, a potash fertiliser. Crops not fed oft' 

 on the ground remove amounts of potash which vary greatly. Beets 

 may remove as much as lOOlbs. per acre, and cereals about 301bs. 

 A table given above (p. 178) gives the relative likings of various 

 fruit crops for potash. The percentage of that element of plant 

 food in soils usually rises with their contents of clay. Reclaimed 

 swamps and sandy soils are almost invariably benefited by the 

 application of potash fertilisers. 



SOIL AMENDMENTS OR IMPROVERS. 



Besides the fertilisers reviewed in the previous pages, soils often 

 need the application of methods of fertilising, which exercises on 

 them both a mechanical and a chemical effect. 



Amongst the most commonly used amendments are : 



Lime, which is especially valuable for the renovation of worn-out 

 soils and for breaking down stiff clay and making it more friable and 

 pervious to water; it supplies plant food; it assists in the decomposi- 



