EXPERIMENT STATION BULLETINS. 



503 



value oi: oUr'I- (4-eatiiieiils, especially iiianure aiul phosplialcs when tlie.v 

 are added singly or together to the soil, 'rhese results are in accord 

 with those obtained from long continued trials in other states. 



pii 



Fijiure .">. 0:its jind Oihor (iraiii Crops are Bi-ni-litcil liy IJiiiiiig. 



Oil tlK- loff is SOPH tlio pffccf of troatinK a Van Bureii county soil with mnnnro and iJcrniMul 



linii'.stone. On the rifjlit. n.anure ulone was iisetl. 



HOW TO DETERMINE IF A SOIL NEEDS LIME. 



There is a general inii»re.ssion that a sample of soil may be taken into 

 the laboratory and the exact amount of lime needed to correct its 

 acidity determined. It is true that a number of methods liave l)een 

 outlined and extensively employed for this purpose and have doulilless 

 yielded much valiia]>le information. But as yet no method has been de- 

 vised wiiich enables one to determine how much lime it is most a<lvan- 

 tageons to use in the field. The results obtained for a given soil by 

 different methods are (piitt; variable and in conseipience the lime recpiiif 

 nuMit of the soil will dc^teiid somewhat on the analytical method em- 

 ployed. 



There are, however, methods of determiniui^ whether or not a soil is 

 in need of lime but which make no attempt to determine the exact amount 

 that should be applied. 



Terhaps the simplest of these methods is the litmus paper test. To 

 make this test the soil is moistened witli rainwater, and made into a 

 ball. This is broken open and a strip of blue litmus paper inserted into 

 the opening and the soil pressed firmly together around the paper. In 

 about five minutes the paper is removed and examined. If the color is 

 pink the soil is considered to be in need of lime. In making this test 

 great care -must be exercised to obtain a good grade of litmus paper. 

 That obtained from the drug store is often not suflBciently sensitive to 

 give satisfactory results. The paper should not be handled when the 



