PART IX 



Bulletins and Papers of Interest to Farmers and Stock 



Growers. 



THE USE OF LIME ON IOWA SOILS. 

 By Geo. B. Corson. 



Soil acidity is one of the most important problems before Iowa farm- 

 ers at the present time. The following questions regarding lime and 

 its use on land are constantly being asked: 



How may I determine whether my soil is acid and in need of lime? 

 Is lime a fertilizer? How much lime is needed per acre? What is the 

 most desirable form of lime to use? Where may I get limestone and 

 how much does it cost? What is the best method of spreading lime and 

 when should it be applied? Will it injure the land? How often will 

 lime need to be applied? Does it pay to use limestone? 



This circular has been prepared to answer these questions and to 

 give further information on this subject. 



IOWA SOILS NEED LIME. 



According to recent tests of soils from all sections of Iowa, fully 60 

 per cent are acid and need lime. There are three principal reasons 

 for the loss of lime from the soil. First, there is a constant removal 

 of lime from the soil in drainage water; second, the organic matter in 

 the soil produces acids when it decays, and a small amount of lime Is 

 used up by these acids; third, crops, especially the legumes, remove 

 large amounts of this material from the soil. These losses cannot be 

 avoided because soils should be well drained, should be supplied with large 

 amount of organic matter, and should contain lime for the use of crops. 



TESTS FOR ACID SOILS. 



Acid soils may be indicated by the presence of such plants as horse- 

 tail rush, sheep sorrell, corn spurry and wood horse-tail. These weeds 

 grow unusually well in acid soils and where they are present in large 

 numbers farmers should test their soils to determine whether they are acid. 



Some legumes such as red clover, sweet clover and alfalfa will not 

 make their best growth on "sour" soils. If red clover fails to grow on 

 soils where good stands of this crop were once secured, it is a fairly good 

 indication that the soil is in need of lime. 



By far the most reliable means of determining whether a soil is acid 

 is to test it or send a sample to the Iowa Agricultural Experiment Station 

 and have it analyzed. A simple method of testing a soil for acidity is by 

 means of blue litmus paper, which may be purchased from most any 

 druggist. 



