474 Field Experiments on Clover-Seeds. 



For this reason I endeavoured to devise a manuring scheme 

 which should recommend itself hy simplicity, and include as far 

 as possible conditions essential to success. After a good deal of 

 deliberation I selected the following substances for field-trials on 

 clover-seeds : — ■ 



1. Nitrate of soda. 



2. Sulphate of ammonia. 



3. Soluble phosphate, in the shape of dissolved bone-ash or 



mineral superphosphate. 



4. Common salt (chloride of sodium). 



5. Muriate of potash (chloride of potassium). 



6. Sulphate of potash. 



7. Sulphate of lime. 



8. Mineral superphosphate and nitrate of soda mixed together 



in equal proportions. 



9. INIineral superphosphate and muriate of potash mixed 



together in equal proportions. 



Perhaps it may not be amiss for me to say a few words in 

 explanation of the choice which 1 was led to make. 



In the first place I was particulaily anxious to ascertain what 

 the effects of potash would be on crops which, like a clover- 

 crop, remove from the soil a large proportion of this important 

 element of nutrition. During the last three years I have tried 

 vipon a variety of crops both sulphate and muriate of potash, as 

 well as foreign crude potash salts, which at present can be pro- 

 cured in England at a reasonable price. Hitherto the results 

 have not been very conclusive, or rather, I should say, in most 

 cases my experience of salts of potash does not warrant me to 

 recommend Avith much confidence the artificial supply of potash 

 to the generality of soils even when it is intended to grow 

 plants which are known to require much potash for coming into 

 perfection. The want of success may be due to a variety of 

 causes. It may be due to the lateness of the season at which the 

 potash manures were applied ; and a better effect might have 

 been produced had these salts been applied to the land in autumn 

 instead of in the spring. Again, it is more than probable that 

 most soils in a fair agricultural condition neither require nor are 

 benefited in the least by the exclusive artificial supply of potash. 

 It certainly is a fact that many soils contain abundance of avail- 

 able potash, and on such soils salts of potash are not likely to 

 produce any effect even when applied to crops which remove 

 more potash from the land than others. The state of combination, 

 as well as the more or less concentrated condition in which 



