Relation of Calcium Carbonate to the Soil Phosphates 



and Acid Phosphate 



BY JAMES L. BUBGE8S, STATE AGRONOMIST. 



Before cnti'iiiii;- ujnm a discussion of this important subject it will 

 be well to call attention to two fundamental propositions to which all 

 informed men readily assent without question. 



First. No plant can be grown to maturity without phosphorus in the 

 soil solution with which the plant is fed. No plant can ripen seed 

 without the aid of phosphorus, which is necessary to the formation of 

 the germ cells. Phosphorus is, therefore, essential to all normal plant 

 growth and development. 



Second. None of our field crops can reach normal maturity without 

 calcium or lime in the soil solution with which the plant is fed. No new 

 jilant cells can be formed without the aid of calcium or lime, usually in 

 the form of calcium phosphate. Some plans (as the legumes) are called 

 "lime plants," so necessary is lime to their normal growth. Calcimn, 

 or lime, is, therefore, essential to the normal development of our ordi- 

 nary crops. 



It is also a matter of common observation that crops grown in lime 

 or calcareous soils are better nourished and are more capable of with- 

 standing untoward climatic conditions, as drought and early frost, than 

 are crops not so well supplied with lime. It is plain, therefore, that 

 both calcium and phosphorus must be present in the soil at the same 

 time, contributing jointly and simultaneously to the normal develop- 

 ment of plant life. 



The above facts have been matters of common knowledge so long as 

 to have become axiomatic. We will now look over some of the litera- 

 ture bearing on. this subject and see what the most eminent authorities 

 in this and other countries have to say about it. 



The value of lime as an aid to crop production was known and prac- 

 ticed in the time of Pliny, and has been increasing in interest and value 

 from his time until the present day. There are, perhaps, a thousand 

 reliable experiments on record that show the use of lime and ground 

 limestone to have very greatly increased crop yields. 



Dr. Hilgard, in his excellent work on soils, states : "The instant 

 change of vegetation when we pass from a noncalcareous region to one 

 liaving calcareous soils has already been alluded to, but it is not neces- 

 sary to be a botanist to see the change in the PROSPERITY of the rural 

 population as one enters the LIME DISTRICT. The single log cabin, 

 with probably a wooden barrel terminating the mud-plastered chimney, 



