84 



Notes on Manures for April. 



[Apr., 



Examine Clover Leys now. — NTow that the winter is over 

 careful inspection of the clover leys is desirable to ascertain 

 whether the general soil conditions are suitable or whether 

 there is a need of lime and of phosphates. The writer is con- 

 vinced that many farmers suffer unnecessary loss of this most 

 valuable crop simply through lack of lime and phosphates. The 

 best time for applying these is at or before the sowing of the 

 clover seed, when, as pointed out last month, there is a marked 

 response in the growth of the young plant. The advantage of 

 inspection now is that it affords guidance for the treatment of 

 seeds to be sown this year: if last year's crop is patchy and the 

 plants are not as healthy as they should be, the newly sown^ 

 seeds should be well dressed with basic slag. 



Difference between Kainit, Sylvinite, Muriate of Potash and 

 Sulphate of Potash. — Our correspondence shows that there is 

 some confusion in the minds of farmers between these sub- 

 stances. 



Sulphate of potash is well known, and being a single substance 

 is always of the same composition so long as it remains of the 

 same degree of purity. It can be used on all crops needing 

 potash, and is free from harmful effects on quality. 



Muriate of potash is also well known to farmers, and in most 

 cases can be used as freeh' as sulphate of potash, with the 

 certainty that it will supply the requirements of crops needing 

 potash. There have been statements that it sometimes injures 

 quality, but the writer has found no direct evidence that this 

 is the case. Careful trials are being made this year. 



Kainit is a mixture of substances graded so as to contain 

 about 12J per cent, of pure potash (K^O), most of which 

 appears to be in the form of muriate. Before the War it con- 

 sisted of about one-third of its weight of comm.on salt (sodium 

 chloride) , about one-third of magnesium salts (apparently 

 chiefly as sulphates) , while the remaining third was muriate 

 of potash with water of crystallisation. It is known to be of 

 great value on mangolds and grassland, where probably all it& 

 constituents help the crop. 



Sylvinite is a newcomer among fertilisers and is being 

 vigorously handled by the Company responsible for the develop- 

 ment of Alsace and Lorraine, where it is found. One grade is 

 sold to contain 12 to 14 per cent, of pure potash (K^O), and 

 this is comparable with kainit; a higher grade contains 20 to 

 22 per cent, of potash. Both differ from kainit in containing 

 no sulphate of magnesia but only muriate of potash and 



