106 



into the pots, and the pots transferred to the green- 

 house. 



For the work which began in the fall of 1914, a fresh 

 sample of soil was collected from the same field from 

 w hich the poor sample of Norfolk sandy loam had been 

 taken the previous year. 



Crops Grown. 



Oats were grown on all pots during the fall and 

 winter of each of the two years when these experiments 

 were in progress. The oats were allowed to grow until 

 quite an advanced stage was reached, when the crop 

 was harvested and weighed. After the oat crop was 

 taken off, corn was planted on all pots in the first year 

 of the work; while the corn or peas followed the oats of 

 the second year. The corn was grown until tassels 

 were showing, or until the corn was w^ell advanced. A 

 good idea of the stage of growth reached in each case 

 can be had from the photographs. All crop weights 

 given are in grams. For further details, see the tables 

 and discussion accompanying the tables. 



Results of Pot Experiments With Cullers Field Soil. 



In table I the results obtained on Cullers Field soil are 

 given. The plants were grown in 2-gallon stoneware 

 pots, each pot containing 20 pounds of soil. Oats were 

 planted in the fall of 1913, and harvested in the early 

 spring of 1914, just after the plants had fully headed 

 out. After the oat crop was harvested, 9 grams of acid 

 phosphate were added to each pot which had not re- 

 ceived phosphate treatment for the oats, and each 

 planted to corn. The corn crop was harvested just as 

 the most forward plants were beginning to tassel. The 

 air dry weights of the two crops, and the combined 

 weights are given in the table In the last column of 

 the table, the results are shown in a relative way, the 

 unfertilized yield being taken as 100. 



