No. 5. DEPARTMENT OF AGRICULTURE. 34'3 



LIME AND COMMERCIAL FERTILIZERS IN THE MAINTEN- 

 ANCE OF SOIL FERTILITY. 



By DR. C. E. THORNE, Wooster, Ohio. 



In 1893 the Ohio Experiment Station began a series of experiments 

 in the use of fertilizers and manure on a tract of thin, sandy clay, 

 lying over shaly sandstones from which it had been largely derived, 

 and which had been brought to a very low state of production by 

 three quarters of a century of exhaustive husbandry. 



In one of these experiments, corn, oats and wheat are grown in 

 succession, one year each, followed by two years in clover and 

 timothy mixed, making a 5-year rotation. Five tracts of land of 

 three acres each are devoted to this test, each crop being grown 

 every season. The tracts are divided into plots containing one-tenth 

 acre each, and different combination of fertilizers or manure are ap- 

 plied to the grain crops, the clover and timothy being left untreated. 

 Every third plot has been left untreated since the beginning of the 

 experiment. 



In planning this experiment no provision was made for the use of 

 lime. At that time the work of field experimentation was in its 

 infancy. The Rothamsted experiments in England had, it is true, 

 been in progress for some forty years, and the experiments at Penn- 

 sylvania State College for ten years, but in neither of these tests was 

 there any evidence that lime was needed, and the assumption seemed 

 to be warranted that the supply of lime, like that of iron, sulphur 

 and several other necessary elements of plant food, might safely be 

 left to take care of itself. 



But very soon it was observed that the clover crop was misbe- 

 having, the harvest which should have been chiefly clover, consisting 

 mainly of timothy, with sorrel and other weeds. The difficulty was 

 at first ascribed to spring frost having destroyed the young clover 

 plants, and we attempted to remedy it by making two sowings. One 

 spring we sowed three times, and assured ourselves that we had a 

 good stand by careful inspection, and jet when the harvest came the 

 clover was not there. We accused the fertilizers of contributing to 

 the trouble by their failure to add to the organic matter of the soil 

 as does manure; but we found that even on the manured land the 

 clover was not a good crop, although much better than on some of 

 the land where fertilizers were used, or on that left untreated. Every 

 year there would be spots of fair clover, which would be larger when 

 rain was abundant and smaller in seasons of drought, but there was 

 never a satisfactory stand, no matter how well the land was fer 

 tilized or manured. 



In 1900 we decided to try the effect of lime, and began by spread- 

 ing quicklime at the rate of a ton per acre over the west halves of all 

 the plots, fertilized and unfertilized alike, the plots being 16 feet 

 wide by 16^ rods long and running east and west. The lime was 

 applied to the land as it was being prepared for corn and was stirred 

 into the surface with harrow and cultivator. The corn was harvested 



