DEPARTMENT OF SOIL TECHNOLOGY 



TEACHING 



During the past year the courses of instruction have been revised. 

 Course i, Principles of Soil Management, is now repeated in the second 

 term. It has been possible to raise the standard of this course by 

 admitting only regular students who have had the prerequisite training, 

 and by providing for others a course — Elementary Soils — which is 

 entirely different in its nature and which cannot under any circumstances 

 be substituted for Course i. 



The number of students registered in undergraduate courses during the 

 year was 274. Twelve graduate students took m.ajor or minor subjects 

 in the department. Of these, four registered for major subjects for the 

 doctor's degree, three took minor subjects for the same degree, four took 

 major subjects for the master's degree, and one a minor for the master's 

 degree. 



The Department has been fortunate in securing the services of Dr. H. O. 

 Buckman as Assistant Professor of Soil Technology, who will give his 

 attention solely to the instruction of college students. The activities of 

 the Department in the lines of college instruction, investigation, and 

 extension each have at least one officer of professorial grade who devotes 

 his time exclusively to the one branch of work. 



INVESTIGATION 



Adams fund investigations 



There has been no change in the nature of the investigations conducted 

 under the Adams Act. The four problems that were reported last year 

 are still under investigation, but new phases of these subjects have been 

 attacked and new methods used. The present status of each problem may 

 be outlined as follows : 



I. Influence of soil moisture on the availability and utilization of plant 

 nutrients in soils. — During the past year the first phase of the work in 

 this investigation has been completed. This consisted of a series of pot 

 experiments in which the soil was kept at certain definite moisture con- 

 tents varying from 15 to 40 per cent of the dry weight of the soil. Plants 

 were grown in some of these vessels, and others of the vessels were 

 allowed to remain under similar conditions except that no plants were 

 grown in them. Treatments of soil in this way extended over a period 

 of four years and comprised a large number of separate experiments, in 



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