OpfFlCIAI, INSPECTIONS 33. 81 



to soils and crops. Those who desire to study these questions, 

 are invited to write to the Superintendent of the Extension 

 Department of the College of Agriculture, University of Maine, 

 Orono, Maine, who will gladly send a list of suitable books 

 and give full information relative to correspondence courses on 

 this subject,* 



Soils vary greatly in their capabilities of supplying food to 

 crops. Different ingredients are deficient in different soils. 

 The way to learn what materials are proper in a given case is by 

 observation and experiment. The rational method for deter- 

 mining what ingredients of plant-food a soil fails to furnish" in 

 abundance, and how these lacking materials can be most eco- 

 nomically supplied, is to put the questions to the soil with differ- 

 ent fertilizing materials and get the reply in the crops pro- 

 duced. How to make these experiments is explained in Cir- 

 cular No. 8 of the Office of Experiment Stations of the U. S. 

 Department of Agriculture. A copy of this circular can be 

 had by applying to the Secretary of Agriculture, Washington, 

 D. C. 



The chief use of fertilizers is to supply plant-food. It is good 

 farming to make the most of the natural resources of the soil 

 and of the manures produced on the ^f arm, and to depend upon 

 artificial fertilizers only to furnish what more is needed. It is 

 not good economy to pay high prices for materials which the 

 soil may itself yield, but it is good economy to supply the 

 lacking ones in the cheapest way. The rule in the purchase of 

 costly commercial fertilizers should be to select those that sup- 

 ply, in the best forms and at the lowest cost, the plant-food 

 which the crop needs and the soil fails to furnish. 



Plants differ widely with respect to their capacities for gath- 

 ering their food from soil and air; hence the proper fertiHzer 

 in a given case depends upon the crop as well as upon the soil. 

 The fertility of the soil would remain practically unchanged if 

 all the ingredients removed in the various farm products were 



*This Station has a circular on Home Mixed Fertilizers that may be 

 had on request to Director Chas. D. Woods, Orono. Farmers' Bulletin 

 44 of the. U. S. Department of Agriculture discussing commercial fer- 

 tilizers will be sent to any address on application to the Secretary of 

 Agriculture, Washington, D. C. The Maine Bulletin, Vol. XI, No. 5, 

 discusses The Restoration of Fertility and Commercial Fertilizers. This 

 can be obtained by writing the College of Agriculture, Orono, Maine. 



