202 



75 bushels of corn per acre, we find a plant food content about as 

 follows : 



Pounds of Plant Food Per 2,000,000 Pounds of Surface Soil. 



Nitrogen 4,500 lbs., 2 per cent possible available in 1 year 90 lbs. 



Phosphorus 1,500 lbs. (too low) , 1 per cent 15 lbs. 



Potassium 32,000 lbs., one-fourth of one per cent 80 lbs. 



Organic matter, 160,500 lbs. 

 Limestone present, 350 lbs. 



A 50-bushel corn crop would need about 74 lbs. of nitrogen, 11.5 

 lbs. of phosphorus and 35.5 lbs. of potassium in addition to the other 

 essential elements usually present, and this amount of plant food could 

 more than be supplied in a soil like the above. 



Plan of Invoicing Fulton County Soils. 



The soil samples chosen numbered 128 and they were collected from 

 the eight townships. Most of the soil samples were taken from 

 surface soil (7 ins. deep), but 38 were from subsoils (6 to 20 ins.). 

 Twenty of the samples were from virgin soil and represent more or 

 less the original fertility of the .soil unchanged by cropping. Many 

 items were noted while the samples were being collected (August, 1016) 

 or information was secured from the people living on the farms as to 

 the prevalent weeds, stand of clover, kinds of timber, grain yield per 

 acre, use of fertilizers and manures, etc. The following determinations 

 were made on the soil samples: fir.st, total organic matter; second, total 

 nitrogen; third, total phosphorus; fourth, pre.sence of carbonates and 

 acidity to litmus. An attempt was made to correlate this data with 

 the yield of corn per acre. It was thought this could be done best by 

 means of graphs. Since the presence or absence of organic matter is 

 so vitally related to crop yield, the soils were grouped into eight series 

 depending on the amount of organic matter present in the soil. The 

 samples are numbered as follows: 



Puchland Twp., 1-10 and 108-111, inclusive. 

 Aubbeenaubbee, 11-19 and 106-107. 

 Henry, 20-24 and 124-128. 

 Newcastle, 25-27 and 112-123. 



