56 MANURING 



ment. The land should be flat and the soil similar in 

 each experimental plot. The plots should have been 

 similarly treated in regard to previous cultivation and 

 manuring. 



The cocoa trees should be of the same variety in each 

 plot, of like age, and be planted at a uniform distance 

 apart. It is also of importance that the same system 

 of pruning should have been applied to the trees in each 

 plot. The plots should be uniform in area and each 

 should contain the same number of trees. Nitrogen, 

 phosphoric acid, and potash are the constituents in which 

 the soil is most likely to be lacking. It may be deficient 

 in one or even two, but most unlikely in all of these 

 ingredients. To test for one constituent four plots will 

 be necessary, including the control plot. The results 

 in this case would not, however, be satisfactory if more 

 than one constituent were lacking in the soil. It is 

 therefore advisable to have eight experimental plots. 

 Each should be at least one-fifth of an acre in area. 

 Strips of land 88 yds. long by 11 yds. wide would be 

 suitable, and, if the trees were planted at 15 ft. apart, 

 each plot would contain 34 trees. At least two rows of 

 trees should be left unmanured between each plot. In 

 the subjoined table are given the weights of the various 

 manures which it is suggested should be applied to each 

 plot. 



No. Name and Weight of Manure 



of Plot. to apply per Plot. 



1. (Control plot) . No manure 



2. . .40 Ib. Sulphate of potash 



3. . . 80 , Basic phosphate 



4. 

 5. 



6. 



7. 



8. 



Nitrate of soda 

 Sulphate of potash and 

 Basic phosphate 

 Sulphate of potash and 

 Nitrate of soda 

 Basic phosphate and 

 Nitrate of soda 

 Sulphate of potash, 

 Basic phosphate, and 



Nitrate of soda. 

 The fertilisers should be mixed with dry soil and spread 



