118 MASSACHUSETTS HORTICULTURAL SOCIETY. 



from the cultivated fields. There is no method of even approxi- 

 mating this loss, so far as I know, but that it is enormous no one 

 can deny. 



The eminent French scientist, Grandeau, estimates that one 

 3-ear's crops in France represent 298,200 tons of phosphoric acid. 

 Of this only 151,000 tons were received, leaving a deficiency of 

 147,000 tons of this one form of plant food which must be made 

 up from outside sources, and right here is where the use of com- 

 mercial and chemical fertilizers comes in. 



Some say, "buy grain," thus adding to j'our farm some elements 

 brought from another farm. Very good, as far as it goes. We 

 can and we do replenish our soils, at the expense of the West 

 and South. When we bu}' a ton of shorts, or of cotton seed, or 

 of corn meal, we are transferring plant food from the land where 

 these grew, to the soil where the manure from the animals to 

 which they are fed, is used. From the narrow local horizon this 

 is right, and so long as the West and South do not object, we 

 should continue this. But, from the broad view of the whole 

 country, this is poor policy, and that system of agriculture which 

 shall be permanently successful must feed its crops, so far as 

 possible, where the}' grew, concentrating bulk}' crops into compact 

 animal products, and leaving as much as possible of the deficient 

 plaut food on the land. But under the best management, the 

 elements of soil- fertility which our rivers carry into the sea must, 

 or should, be made good by utilizing all waste products from 

 slaughter houses, gas works, iron furnaces, and various other 

 manufactories, as well as the stored-up mineral wealth which 

 is found in many countries. 



(o.) The feeding of plants is not essentially different from the 

 feeding of animals, except that the soil, in itself, contains most of 

 the food required for them, only a few substances being needed 

 from outside ; while with the animal everything must be supplied. 

 The materials containing the deficient plant food, — that is, fertili- 

 zers, — are numerous, and their number is increasing. As manu- 

 facturers turn their attention towards the utilization of waste 

 products, they find new substances which by proper treatment 

 may be made to supply some one needed form of plant food, and 

 in the following table I have classed those materials which are 

 most common, giving not only the kind and amount of plant food 

 which they contain, but also the cost per hundred pounds, with 



