1889.] PUBLIC DOCUMENT — No. 4. 25 



The ash is the part that interests the farmer, because it 

 contains the substances which we are obliged to furnish in 

 fertilizers. But the question at once comes up, do we need 

 to furnish the whole of the 440 pounds ? It has been found 

 that we do not need to do this ; and, that we may know what 

 is needed and what is not, I have separated the ash in this 

 small bottle into the various substances contained in these 

 vials. I will give the substances and the amount per acre : 



Phosphoric acid, 47 lbs. 



Potash, 130 lbs. 



Soda, 18 lbs. 



Lime, 65 lbs. 



Silica, 162 lbs. 



Magnesium 18 lbs. 



440 lbs. 



There was also seventy pounds of nitrogen contained in 

 the albuminoids. 



In the table we see that this crop removed from the soil 

 forty-seven pounds of phosphoric acid ; and, as will be shown 

 later, this substance is one that is usually deficient in worn- 

 out soils. Potash is another element that more frequently 

 fails than any other. Our crop removed 130 pounds of 

 this. 



Soda has been shown to be less essential than almost any 

 other substance in the ash ; plants can and have been grown 

 in the absence of this. Lime is essential to the growth of 

 plants, but it is not often deficient in New England soils. 

 The speaker who preceded me has shown you that for 

 tobacco it is necessary to apply lime, but for most crops on 

 most soils it is not necessary to make any additions to the 

 lime already present ; thus, our sixty-five pounds of lime 

 may be disregarded. All of you have noticed the hard 

 glazing or coating on the outside of corn stalks, and on 

 straw, etc. ; this is silica. It is never applied as a fertilizer, 

 for the soil yields enough in most cases ; consequently, this 

 162 pounds may be left out of the account in fertilizing for 

 our farm crops. 



The eighteen pounds of magnesia also can be set aside in 

 nearly all cases, though there are soils where it seems bene- 



