80 T. Lyttleton Lyon and James A. Bizzell 



The quantity of nitrogen in the drainage water from tho unplanted soil 

 was much greater than in the water from the cropped soil, there being 

 seventeen times as much in the former as in the latter. The apphcation 

 of hme had no effect on the amount of nitrogen contained in the drainage 

 water, neither did it affect the quantity in the non-leguminous crops. 

 There was more nitrogen in the dra'nage water of the unplanted tanks 

 than in both the drainage water and the crops of the planted tanks. Some 

 plants used a greater quantity of soil nitrogen than did others, without 

 causing the nitrates in the drainage water to become less. The data 

 appear to support the idea that certain kinds of plants have a depressing 

 influence on the production of nitrates in soil. 



The quantity of calcium in the drainage water of the unplanted soil 

 was greater than that in the crops and the drainage water combined on 

 the planted tanks. Because of this, a conservation of 181 pounds of 

 calcium per acre was effected b}^ cropping the soil instead of leaving 

 it bare. 



The larger removal of calcium in the drainage water from unplanted 

 soil than from cropped soil \vas apparently due in large measure to the 

 much greater quantity of nitric acid leached from the unplanted soil. 

 Carbonic acid also is a factor in the greater removal of calcium from the 

 bare soil. Not only was the total quantity of bicarbonates greater in 

 the drainage from the bare soil, but also the concentration of bicarbonates 

 was greater. The large amount of carbonic acid excreted by the roots 

 of plants was apparently of no effect in increasing the solvent action of 

 the soil water on calcium, probably because the soil water was already 

 saturated with carbon dioxide. 



The application of lime at the rate of 3000 pounds per acre did not 

 increase the quantity of calcium in the drainage Avater or in the ash 

 of the crops produced. Altho the total removal of calcium in either the 

 drainage water or the crops was not greater from the limed than from 

 the unlimed soil, the percentage of calcium was, in the main, somewhat 

 higher in the crops raised on the limed soil. Annual applications of 

 potassium sulfate at the rate of 200 pounds per acre materially increased 

 the quantity of calcium in the drainage water. 



To keep the soil supply of calcium up to its present amount would 

 require an annual application of 514 pounds per acre if the soil were 

 kept bare of vegetation, or 271 pounds per acre if it were cropped 



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