176 STATE BOARD OF AGRICULTURE. 



the various kinds of commercial fertilizers these three substances in 

 their various forms of combination demand exclusive attention, and it is 

 the amount and condition of these that determine the value of any 

 fertilizer. 



LEADING KINDS OP FERTILIZERS. 



The leading kinds of fertilizers may be classified as follows: 



1. Complete Manure, which contains nitrogen in some combination, such 

 as a salt of ammonia, nitrate of soda, or organic nitrogen; potash, as 

 muriate or sulphate (German Stassfurth salts) or wood ashes; and phos- 

 phoric acid as a phosphate of lime. It is called a complete manure 

 because it contains all of the three materials most essential for plant 

 growth, and most likely to be deficient in a field after long cropping. 



2. Plain Phosphate, which may be in the form of superphosphate, 

 soluble in water or solution of citrate of ammonia, these being called 

 available, because they are readily taken up by the roots of plants; and 

 ground phosphate rock, an insoluble form. The bone phosphate and rock 

 phosphate are changed into superphosphate by the action of sulphuric 

 acid, removing a part of the lime, as sulphate. 



The soluble phosphate is especially beneficial to plants in the early 

 state of their growth, giving them a good start. In later stages of growth 

 when the plant by its roots can forage for food in the soil, the insoluble 

 phosphate may have nearly as beneficial an effect. 



Phosphates promote the formation of flower and fruit and secure 

 earlier ripening. They may wisely be used on vines and succulent fruits 

 that are liable to be cut by early frosts in autumn, securing early crops 

 with better prices and avoiding the loss of the entire crop by untimely 

 frosts before the most of the crop had ripened. Fruit trees sometimes 

 blossom year after year without producing fruit. This is often caused by 

 storms at the period of flowering, but it may be caused by constitutional 

 weakness, in consequence of which pollen of vital power is not formed. 

 In such cases the use of active phosphates is worthy of trial. 



3. Bone Meal contains phosphate of lime and animal matter rich in 

 nitrogen, and hence is very valuable for manure where we desire a pro- 

 longed influence. It is well adapted to grass lands and lawns, and is 

 free from the bad odor often given off by mixed fertilizers. Moist 

 meadows are benefited by a dressing of bone meal. If the bones that 

 now adorn the back yard and pasture lot should be ground into a powder 

 and scattered on a crop-worn field, the results would surprise some 

 farmers. 



4. Potash Manures. The best and cheapest is that neglected home 

 product — wood ashes. These contain an average of five per cent of 

 potash, besides a sensible amount of phosphate, and a very large amount 

 of carbonates of lime and magnesia; they are an all-around plant manure 

 so far as mineral matter is concerned, supplying each ash element. 



Unless the farmer can bring into a active form the great store of potash 

 in his soil, he will then have to buy the German potash salts, the muriate 

 or sulphate. These salts are yearly coming into greater prominence as 

 potash fertilizers, but their sale in Michigan in separate form has not 

 been large. 



The influence of potash on plant life is masterful; no plant can grow 



