AGRICULTURAL CHEMISTRY 



A. E. VINSON, C. N. CATLIN, S. W. GRIFFIN 



The Department of Agricultural Chemistry has been strength- 

 ened materially and the work promoted by the appointment of 

 Mr. C. N. Catlin, formerly Assistant Chemist, as Research Spe- 

 cialist and the addition of an assistant chemist for analytical work. 

 Mr. Howard W. Estill was Assistant Chemist from January, 1919, 

 until September; since that date Mr. S. W. Griffin has served in 

 that capacity. 



The number of analyses of irrigation water and soil for alkali 

 made by the department has been increasing continually with the 

 increasing agricultural development of the State. While this is a 

 public service akin to the extension service and county agent work, 

 it occasionally presents problems of more general interest and im- 

 portance. With the aid of the Assistant Chemist we have been 

 able to meet these demands and make a number of feeding stuff 

 analyses for other departments, although considerable work of 

 this kind remains uncompleted. A very few miscellaneous exami- 

 nations, mostly for poisons, have been made. 



ADAMS FUND WORK 



The research work of the department has been concentrated 

 on the study of black alkali. In this connection progress has been 

 made in working out the technique of a method of determining the 

 colloidal swelling of dry soils when wetted. The further study of 

 the influence of chemical treatment on the rate of percolation 

 through black alkaline soil is being deferred until it can be accom- 

 panied by and correlated with the colloidal swelling studies. 



Pot cultures are being conducted with a view of establishing 

 the tolerance for black alkali in a type soil, which it is proposed 

 to use later in the study of the influence of concomitant conditions 

 on tolerance. For this purpose soils of uniform texture from close 

 proximity in the same field, but showing different black alkali on 

 analysis, are selected and mixed to give any desired series. The 

 white alkali constituents are added to bring all pots to uniform 

 concentration and all other influences are equalized as far as pos- 

 sible. Excessive plant foods are given all pots, water supply is 

 held constant in all cases, soil temperatures equalized, and pedigreed 

 seed from a single mother plant used. After a definite point of 

 tolerance has been established with the type soil and strain of 



