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IOWA DEPARTMENT OF AGRICULTURE 



IOWA LIMESTONE SUITABLE FOR CORRECTING SOIL ACIDITY. 



There are many quarries in Iowa that contain limestone suitable for cor- 

 recting soil acidity. This material is being ground by individuals and in 

 some communities co-operative grinding is being done. By the use of 

 portable crushers, ground limestone may be produced at a moderate cost. 

 A list of firms offering limestone crushers for sale is given in the latter part 

 of this circular. 



The Soil Section is prepared to test limestone to determine whether 

 it is desirable for agricultural purposes. Samples of limestone should 

 be taken with care as the stone is exceedingly variable in different parts 

 of the same quarry. Select samples from 10 different parts of the same 

 quarry, grind and mix thoroly. Place about one-half pint of the mixture 

 in a clean container and send to the Soils Section, Iowa Agricultural Ex- 

 periment Station, Ames, Iowa. 



The test is made free of charge and results of analyses will be reported 

 as promptly as possible. 



LIMESTONE ArPLICATIONS PAY. 



Limestone will not injure the land in any way; it benefits soiis by mak- 

 ing them sweet, improves their physical condition, aids in the growth of de- 

 sirable soil bacteria, makes more plant food available and increases yields 

 of crops, especially clover and alfalfa. 



The following summary of results secured by making one application 

 of limestone to acid soils, indicates that this is a profitable material to use. 



THREE TEAR TEST AT BRYANT. IOWA. 



FOUR TEAR TEST AT CALUMUS, IOWA. 



EFFECT OF LIMESTONE ON SOY-BEANS, DAVENPORT, IOWA. 

 Treatment Yield, 1918 



No treatment —3,345 pounds per acre 



Manure - 3,980 pounds per acre 



Manure and' Limestone 4,760 pounds per acre 



The results show that limestone not only increased the yield of clover, 

 but also brought about a considerable increase in the yield of soy-beans, 

 wheat, corn and oats. Other results from all parts of the state show that 

 limestone when applied to acid soils, gives profitable increases in crop 

 yields. 



Lime loill not take the place of viamire or other fertilizers. It should 

 however, have a place in all systems of permanent fertility, which include 

 the rotation of crops, the use of limestone, manure and legumes and turn- 

 ing under the last crop of clover and all crop residues. 



