180 Bulletin 228. 



and proved to be of very inferior quality, to the annoyance and dis- 

 gust of both seller and buyer. 



The soil upon which the Cornell experiments have been conducted 

 is a gravelly loam underlaid by sand. The natural drainage is, 

 therefore, very effective and the soil is better adapted to withstand 

 an excess rather than a deficiency of moisture. Previous to the 

 beginning of these experiments in 1895, the land had been subjected 

 to a regular four years' rotation consisting of wheat, clover, corn and 

 oats. In 1894 the area was planted to corn, having received about 

 10 tons per acre of barn manure during the previous winter. While 

 this soil was recognized to be in a good state of fertility owing to 

 previous rational treatment, it did not appear to hold an unusual 

 stock of plant-food. In 1896 analysis of soil from these acre plats, 

 computed for a depth of eight inches, indicated in the fine soil the 

 following amounts of the constituents named below: 



Phosphoric acid 2 , 523 lbs. 



Nitrogen 2,049 lbs. 



Potash 8,042 lbs. 



In Roberts' "The Fertility of the Land" analyses of 49 soils are 

 tabulated, and, computing for the same depth, the average amounts 

 of potential plant-food per acre are: 



Phosphoric acid 4 , 219 lbs. 



Nitrogen 3,053 lbs. 



Potash 16,317 lbs. 



It appears, then, that this soil contained in the fine material only 

 about one-half as much phosphoric acid and potash and about two- 

 thirds as much nitrogen as an average soil. The gravel which did not 

 pass through a sieve of 18 meshes to the inch and which constituted 

 about 42 per cent of this soil, contained somewhat more phosphoric 

 acid and slightly less potash per acre than did the fine soil. Some 

 of this gravel was in a soft, rotten condition and pulverized very 

 easily. For six years experiments in the culture of potatoes were 

 conducted upon this area, though potatoes did not follow potatoes 

 year after year on the same plats. The potato crops alternated with 

 crops of beans, sugar beets, corn or oats, and peas. Large yields of 

 these various crops were taken from these plats each year and without 

 the application of manure or fertilizer, the object of the series of 

 experiments being to demonstrate the effect upon the yield of very 

 thorough and judicious tillage of the soil. 



Place of potatoes in the rotation. In all the plat experiments with 

 potatoes conducted at this Station, the potatoes were planted on land 



