MINERAL COMPOSITION OF CROPS 



33 



soil, while the phosphorus contents were consistently the lowest in 

 those grown in the Cecil soil. Bishop's data also show that the calcium 

 and phosphorus contents vary inversely, so that the calcium-phos- 

 phorus ratio fluctuates even more markedly. 



Weathers' (580) recent analyses of lespedezas from three soils of 

 varying fertility in Tennessee show quite clearly the effect of soil and 

 locality as contrasted with that of variety. The data tabulated in the 

 appendix show that the hay grown in the Maury silt loam, a gray- 

 brown podzolic soil developed from a phosphatic limestone, contains 

 the highest quantity of calcium and phosphorus, while that grown in 

 the Clarksville loam contains the least quantity. The phosphorus 

 content of the lespedeza grown in the Clarksville loam, a nonphosphatic 

 soil, is less than half that grown in either the Maury or the Cumberland 

 soils, and there is a corresponding disturbance in the calcium-phos- 

 phorus ratio. 



Pierre (17x) analyzed a number of grass, clover, and alfalfa samples 

 growing in association in old established pastures in West Virginia, 

 and his data for alfalfa are presented in table 14. The collections of 

 grass and clover samples were not made at any stated stage of maturity 

 nor at any uniform time, and they are not, therefore, comparable. 

 Likewise, his soils were chosen in different localities, so that rainfall, 

 management, and other factors might have influenced the composition 

 of the plant. These data indicate that throughout the season all 

 cuttings of alfalfa grown in the Hagerstown soil were lowest in phos- 

 phorus as well as calcium. This is in relative agreement with the 

 available phosphorus in the soils, although the results as between 

 DeKalb and Hagerstown are contradictory to what would be expected 

 unless amendments were used liberally on the former. 



Table 14. — Calcium and phosphorus in alfalfa 



West Virginia 



[Pierre (17x)] 



grown in different soil types in 





Ca 



P 



Cutting 



DeKalb 



silt 

 loam 2 



Holston 



silt 

 loam 3 



Hagerstown 



silt 



loam 4 



DeKalb 

 silt 

 loam 



Holston 

 silt 

 loam 



Hagerstown 

 silt 

 loam 



First 



Percent 



2.80 

 1.85 

 2.18 



Percent 

 3.22 

 1.98 

 2.15 



Percent 

 1.92 

 1.43 

 1.79 



Percent 

 0.184 

 .324 



.268 



Percent 

 0.166 

 .245 

 .240 



Percent 

 0.139 





. 171 



Third 



.195 









2.28 



2.45 



1.71 



.259 



.217 



.168 







i Harvested at one-third to one-half bloom. Moisture-free basis. 



2 Available phosphorus, 16 p. p. m.; pH, 6.83. 



3 pH, 7.30. 



* Available phosphorus, 9 p. p. m.; pH, 6.20. 



Magistad (15x) analyzed five varieties of grass, each grown in four 

 different soil types in Hawaii. His data (unpublished) are very con- 

 sistent in indicating definite relationships between the calcium and 

 phosphorus contents of all varieties and each of the soil types. Thus, 

 all varieties grown in certain soils are low in these constituents, while 

 those grown in other soils are high. The predominance of soil over 

 variety is quite marked in these experiments. 



257897°— 41 3 



