IV LETTERS OF SUBMITTAL. 



and the chemical determinations were made by them and by 

 ~F. R. Pember and J. C. Hogenson. 



F. H. KING, 



Chief of the Division of Soil Management. 

 PROF. MILTON WHITNEY, 



Chief of the Bureau of Soil*. 



WASHINGTON, D. C., June 27, 1904. 



SIR: In our earlier investigations, relating to the influence 

 of tillage, and especially to that of deep and shallow cultivation, 

 upon the yields of crops, there were relations observed which 

 made it appear that such tillage exerts an influence upon, yield 

 other than that due simply to the effect it may have upon soil 

 moisture. Moreover, in investigating the causes of the rela- 

 tively low fertility of so many of the Southern soils, it was 

 felt, on account of the excessive surface washing which is char- 

 acteristic of the region in question, that if notable amounts of 

 readily water-soluble plant food materials are brought by capil- 

 larity to the surface during drying times, the carrying of these 

 away in the surface drainage may he one of the causes of their 

 low productive capacity. 



It appeared very important, therefore, from the practical 

 standpoint, to investigate the movements of plant food mater- 

 ials, as influenced by capillarity, in these Southern! soils. The 

 paper which is submitted herewith gives the results of investi- 

 gations; relating to this subject, carried on during the seasons 

 of 1902 and 1903. 



This paper, like the other four which have been, submitted, 

 is the result of co-operative and concerted effort on the part of 

 most of the men of this Division and credit is due J. O. Belz, 

 W. C. Palmer, A. H. Snyder, J. W. Xelson, Dr. Oswald 

 Schreiner, J. C. Hogenson, F. D. Stevens, H. L. Belden, A. T. 

 Strahorn, F. R. Pember, Jay F. Warner, F. C. Schroeder and 

 W. S. Lyman. 



F. BO. KING, 



Chief of the Division of Soil Management. 

 PROF. MILTON WHITNEY. 



Chief of the Bureau of Soils. 



