New York Agricultural Experiment Station. 



67 



five years in Pennsylvania, together with much other evidence from 

 this and from foreign countries, have shown that ground limestone 

 gives at least as good results and often better than its equivalent 

 in burned lime. These experiments cover soils of various types, 

 containing much and little organic matter; and they deal with small, 

 medium and large applications of lime, and with nearly all general 

 farm crops. 



Ohio experiments. — At the Ohio Station comparative experiments 

 have been made with equivalent amounts of freshly-burned lime, 

 ground limestone, air-slaked lime and hydrated lime in a rotation 

 of corn, oats and clover. The work has been carried out each year 

 on three different fields. The average results for seven years are 

 given below: 



Burned Lime vs. Ground Limestone: Ohio Experiments; 7 Years' Results. 



The values of the increased crop yields are computed at the follow- 

 ing figures: corn 40 cents per bushel, oats 30 cents, corn stover, $3 

 per ton, oat straw $2, hay $8. These prices are of course below the 

 market price of these crops, but the lime or fertilizer gives us the 

 increase standing in the field and so ample allowance must be made 

 for harvesting and handling the increased crop and for applying the 

 lime or other materials. 



In these experiments the land was in good condition at the outset, 

 yielding GO to 70 bushels of corn per acre, so that the chief problem 

 has been to maintain the yield. Lime and manure have not only 

 maintained but have decidedly increased the yields. Manure is 

 applied to the clover sod before plowing and the lime is applied to 

 the rough surface after plowing. It is important to note that in 

 this experiment the amounts of the different forms of lime that are 

 used in comparison are smaller than are needed by the soil, as shown 

 by heavier applications giving larger increases in crop. This fact 

 makes the comparison the more accurate. 



