210 THE CEREALS IN AMERICA 



indicated (i) by the per cent of lime (CaO) present;* (2) bj 

 the acidity of the soil, which may be determined in quite sour 

 soils by bringing the moist soil into contact with neutral litmus 

 paper under proper precautions ; ^ (3) by the excessive adhesive- 

 ness of clay soils ; (4) by the character of the vegetation, or a 

 change in the characteristic vegetation, or (5) by the persistent 

 failure of certain crops, such as clover and beets. The most 

 satisfactory method, however, of determining the need of lime is 

 by applying it under conditions which make it possible to tell 

 whether there is any increase of crop due to liming.^ 



294. The Application of Lime. — The equivalent of from one 

 to four tons or from twenty-five to 100 bushels of quick lime 

 (CaO) may be applied to land intended for maize. Ordinarily 

 the amount should not exceed fifty bushels.^ (122) 



The freshly burned (quick) lime may be applied directly to 

 the field, where it soon slakes, after which the land may be 

 plowed, care being taken not to plow too deep. Unless it is 

 ground, however, it is difficult to spread quick lime evenly. In 

 order to reduce it to a fine powder the lime may be put in piles 

 of two or three bushels at any convenient time in the fall, where 

 the air, rains and moisture from the soil slake it. Better results 

 will be obtained if the ground is scraped off down to moist soil 

 where the lime is placed and the pile covered with moist soil. 

 If the soil is dry, a half pail of water may be added to each pile. 

 As soon as possible, the piles should be spread with a shovel 

 and the land plowed. Although more laborious, it is better 

 to apply the slaked lime to the plowed land in the spring and 



1 For agricultural crops, 0.2 per cent is usually considered the minimum re- 

 quirement. This can be determined only by chemical analysis. 



2 R. I. Bui. 46, p. 100. 



3 For full discussion on the use of lime, see The Agricultural Use of Lime in 

 Pennsylvania. By Dr. William Frear, 6th Ann. Rpt. Penn. Dept. of Agr. (1900), 

 PP- 193-353- 



4 The legal weight of a bushel of lime varies in different States from seventy tt 

 eighty pounds. 



