12 Subtropical Vegetable-Gardening 



Some combinations, however, cake, and require regrinding, 

 and for such it would be cheaper to have the work done at 

 the factory. Some vegetable-growers do not have a suit- 

 able floor, or a plasterer's sieve, and scales at hand. For 

 any who should wish to mix their own fertilizers, and for 

 those who wish to have special combinations prepared, 

 the formulas given in this book are followed by a list of 

 quantities of fertilizing materials. 



A method which has been successfully practiced for 

 the home mixing of fertilizers, was to spread the weighed 

 and screened materials on the barn floor, in layers one 

 above the other, the bulkiest at the bottom. The pile 

 was mixed by shoveling together four times, and then 

 bagged. Analysis showed that the mixing was perfect. 

 It is well not to mix lime (or Thomas slag which contains 

 lime) with other fertilizers; for by so doing ammonia 

 may be lost, and phosphoric acid made unavailable, or the 

 mixture may set hard. 



HOW TO COMPUTE THE AMOUNT OF FERTILIZER IN A GIVEN 

 FORMULA 



It is important that one should be able to compute the 

 amount of any essential fertilizer element contained in a 

 certain formula. Unless one is able to find this out, one 

 cannot make an intelligent use of the substance. Very 

 often a high-grade and a low-grade fertilizer can be pur- 

 chased on the same market : then it is important that the 

 relative values of these should be secured in order that 

 one may buy intelligently. It does not concern us further 

 than the difference in handling, whether it is necessary to 



