EXPERIMENT STATION REPORTS. 



339 



K 



N 



Ca 



S 



About 1/4 to % of the till plains area is composed of sandy loam. These 

 soils were originall}^ covered with beech, maple, oak and basswood. The 

 plant food contained in the surface soil of representative samples is 

 shown below: 



P K N Ca S 



1169 



718 



31890 

 33170 



3756 

 2352 



13658 

 10728 



1166 

 956 



The morains are composed principally of sandy loams although there 

 are some silt loams, loam and sand. The sandy loams originally grew 

 beech, maple, elm, oak and hickory. The pounds of plant food in the 

 surface soil are shown below: 



P K N Ca S 



1325 

 869 



28370 

 31160 



2296 

 1064 



11930 



8970 



1037 

 613 



The sands are characterized by growths of scrub oak and poplar with 

 some maple and elm in the more fertile areas. The composition of these 

 soils is shown below : 



P K ' N Ca S 



1118 

 865 



25190 

 27710 



1036 

 1176 



9778 

 10200 



668 

 620 



The outwash plains area consists almost entirely of medium sands 

 which grew oak and poplar. The variableness in composition of these 

 sands is shown in the table below : 



P K N Ca S 



563 

 1044 



23530 

 25120 



1288 

 980 



8441 

 11373 



936 



507 



The above results suggest that phosphorous is an important considera- 

 tion for increased crop production, and the permanent systems of agri- 

 culture, field experiments are bearing out these suggestions. 



Galvanized iron cans 2 feet in diameter and 2-4-6 and 8 feet in 

 length were sunken in the ground, filled with coloma sand tj^pical of 

 large areas in Michigan, and covered with glass to prevent water from 

 entering. Each tank was constantly supplied with water by means of a 

 block tin tube in the bottom connected with a reservoir. In the spring 

 of 1916 these tanks were seeded to oats and the surface soil watered un- 



