372 



MAIZE 



CHAP. 

 VIII. 



jjiS. Potassium. — At Koedoespoort, Prof. Watt obtained 

 an increase of 452 lbs. of maize per acre the first year and 360 

 lbs. the second year, after an application of 150 lbs. per acre 

 of sulphate of potassium, but the net value of the increase due 

 to manuring was only 5s. 5d. per acre. At Potchefstroom 

 the use of sulphate of potassium (150 lbs. per acre the first 

 year, and 75 lbs. in each of the two succeeding years) resulted 

 in an average loss of 252 lbs. of maize-grain per acre, valued at 

 10s. As the cost of the manure was 16s. id. per acre, the 



Fig. 129. — Effect of sulphate of potassium on maize (cf. Fig. 126). 



total loss due to its use was £1 6s. id. per acre. As sulphate of 

 potash is considered the least deleterious of all potassic manures, 

 it has been suggested {Holm, 1) that it is not likely that either 

 kainit or chloride of potassium (" muriate of potash ") would 

 give an_\- better results ; but it has been pointed out by an 

 agricultural chemist that it is just possible that the property 

 possessed by kainit of holding moisture — clue to its sodium- 

 chloride content — may prove it to be better than potassium 

 sulphate for such crops as arc not injuriously affected by the 



