CROPPING CONSERVES LIME 247 



marl are disagreeable to handle because of the dust inhaled. 

 Wearing a moist sponge over the nose is a good precaution. 



Applying Lime As a Top-Dressing. The application of finely 

 pulverized limestone, marl and thoroughly air-slaked lime as a 

 top-dressing on sandy soils for young clover or alfalfa may prove 

 quite beneficial, though best results may be obtained by liming 

 the plowed field sufficiently before seeding. The openness of a 

 sandy soil enables the fine lime particles to be carried down more 

 or less into the soil. Top-dressings on heavy silt and clay loams 

 have not given satisfactory results, for these soils do not permit 

 the entrance of lime particles as do sandy soils. 



Sometimes a farmer wishes to lime his spring's seeding of clover 

 on open silt loam, for example. In such a case, partially air- 

 slaked or hydrated lime, finely divided, applied at the rate of a ton 

 and a half or two tons to the acre early the following spring before 

 the frost is out may prove beneficial. Such an application should 

 not be made after the young plants have started their new year's 

 growth, because sufficient caustic lime may be present in the mate- 

 rial to injure them. 



The application of lime as a top-dressing for pasture and per- 

 manent hay lands rarely proves profitable. The lime, exposed to 

 rain as it lies on the firm surface, loses its fine physical state, and 

 is taken but slowly into the body of the soil. 



How Often to Lime. The effect of even a moderate application 

 of lime on an acid soil lasts a number of years. Leaching experi- 

 ments have shown that the lime added to an acid soil does not 

 leach out so rapidly as is commonly believed. Some experiments and 

 field tests have shown that when agricultural lime is mixed into the 

 top six inches of an ordinary acid soil, it passes downward very slowly. 



On some fields which were limed more than ten years ago, the 

 effect of the lime seems to be just as apparent now as then. When 

 an acid soil is given an application of lime sufficient to neutralize 

 all the acidity in the surface six or eight inches, subsequent liming 

 may not be necessary for many years. The need of more lime can 

 easily be determined by testing the soil for acidity. 



Cropping Conserves Lime. On an acid silt loam at the Cornell 

 Station, New York, an application of burnt lime, at the rate of 

 3000 pounds per acre, did not increase the amount of lime found 

 in the drainage waters from that soil. 7 These leaching experiments 



7 Cornell Sta. Memoir 12, 1918. The soil was acid in the first 3 feet and 

 not acid at the fourth foot in depth. 



