26 MISC. PUBLICATION 3 6 9, U. S. DEPT. OP AGRICULTURE 



contents. It is interesting to note that the highest phosphorus con- 

 tents were found in hemp grown in what Moore's descriptions indicate 

 to be the Maury silt loam, a soil derived from phosphatic limestone. 



As early as 1909, Russian agriculturalists were using soil char- 

 acteristics as units in the study of plant composition. Kossowitsch 

 {320) determined the absorption of phosphorus by the grain and straw 

 of flax, oats, and mustard and by red clover and hays. He reported, 

 for example, that a greater quantity of phosphorus was absorbed by 

 the mustard grown in a Chernozem than in any other soil. 



Ames (7) in 1910 analyzed several wheat crops grown in different 

 soils from the fertility plots at the Ohio Agricultural Experiment 

 Station. His data indicate little or no difference in the phosphorus 

 contents of either grain or straw grown in soils at Wooster and at 

 Strongsville, but the potassium in the straw from Strongsville is 

 nearly 50 percent higher than that in the Wooster soil, and this 

 difference is in agreement with the values reported for potassium solu- 

 ble in N/5 HN0 3 in each of the soils. No difference in available 

 phosphorus was found, which is also in accord with the similar phos- 

 phorus content of the plants. 



In their study of the composition of bluegrass in different parts of 

 Ohio in 1910, Forbes, Whittier, and Collison {195) observed that 



while the mineral content of vegetable crops is without doubt the resultant of a 

 considerable number of varying factors, the most important of these is the com- 

 position of the soil. While it seems unlikely that the variations in soils would 

 cause acute or immediately perceptible effects on animals in Ohio, it seems 

 entirely probable that in the course of the lifetime of animals they do cause, 

 through a gradual molding of the growth, differences of considerable practical 

 importance. 



They reported that samples of bluegrass (collected when first com- 

 ing into bloom) taken from some pastures in Ohio contained more 

 than twice as much phosphorus or calcium as did those from other 

 pastures. They also observed that while the inherent fertility of the 

 soil was important, the use of manure and other fertilizers on poor 

 soils often resulted in bluegrass rich in mineral nutrients. 



Pot tests similar to those of Wiley and Moore were conducted by 

 Lemmermann, Einecke, and Fischer in 1911, using German soils (844)- 

 They grew oats, barley, rye, and wheat, and in every case the straw 

 from the plant grown in a sandy soil from near Petkus contained the 

 lowest amount of calcium. This was not typical of sandy soils, how- 

 ever, for another soil of this type produced crops that compared 

 favorably with loamy sands and sandy soils of very high humus con- 

 tent. The differences in plant composition were distinctly not related 

 to soil structure. 



Gile {208) in 1911 reported that the ash of plants grown in calcareous 

 soils differs from the ash of plants grown in noncalcareous soils chiefly 

 in containing a larger amount of calcium and a smaller amount of 

 iron. Chlorotic pineapple plants were produced in Puerto Rican soils 

 to which limestone had been added, and the iron content in these 

 plants was less than half that in plants grown in the more acid soils. 



Cohen {116), investigating in 1914 the composition of tobacco 

 grown in Javanese soils, found some relationship between available 

 phorphorus content of the soil and that of the plant, but none between 

 the potassium of the soil and plant. In general the heavier soils, poor 

 in citric acid-soluble phosphorus, produced a tobacco with a lower 



