APPLICATIONS AT SUCCESSIVE PERIODS. 



97 



sown as a top-dressing upon the young corn in spring. It 

 may not be the same, however, with other manuring substances, 

 on different soils and upon crops of other kinds. 



b In early spring about the end of March or beginning of 

 April. 



c About the end of May or beginning of June, the actual 

 date to be determined by the nature of the plant and the state 

 of its growth. 



It is not to be supposed that crops, even when they are con- 

 siderably advanced, are entirely beyond our reach. Mr William 

 Alexander of Ballochmyle top-dressed a failing crop of beans 

 with a mixture of. gypsum and common salt, even after they 

 were in fower, and they grew up to be the admiration of the 

 district. 



The following scheme represents the form of this series of 

 experiments: 



2. At successive periods applied in successive portions. 



Suppose two cwt. to be the quantity we wish to add per 

 imperial acre, then to one pair of patches the whole quantity 

 should be added at once, and to another pair one-half at each 

 of two successive periods, as in April and in May, and to a 

 third pair one-third at each of three successive periods. The 

 first application would be as follows : 



