76 SCIENCE AND SOIL 



These New York soils are somewhat richer in phosphorus than 

 most of the older residual soils, and noticeably richer than the 

 average loessial soils of the older formations. 



The ten samples of gravelly loam show an average phosphorus 

 content of 2170 pounds in 2 million of soil, which is about the same 

 as the average of the earth's crust. 



With one notable exception these soils are very rich in potassium, 

 although not quite equal to the average loessial soils of the corn 

 belt. 



Two of the common New York soils (loam and gravelly loam) 

 exceed 5000 pounds per acre in the nitrogen content of the surface 

 6f inches, an amount which represents approximately the average 

 of the most abundant prairie soils of the corn belt, while the three 

 soils, clay loam, sandy loam, and slaty loam, contain about one 

 half as much. 



In the peaty soil we find another very abnormal soil type, which 

 it is instructive to compare with the barren soils of Germany and 

 Maryland, with the depleted long-cultivated soils of India, Turkey, 

 Russia, and Africa, with the coral limestone soil of the Bermuda 

 Islands and the limestone soils of Cuba, and with the phosphatic 

 soils of Tennessee and Kentucky. The peaty soil contains in a 

 6f -inch stratum nearly ten times as much nitrogen, nearly twice as 

 much phosphorus, and only one tenth as much potassium as the 

 general average of the most common American soils. 



The soil on the Experiment Station farm at the State College, 

 Pennsylvania, contains 2320 pounds of total nitrogen, 1080 pounds 

 of acid-soluble phosphorus, and 5600 pounds of acid-soluble po- 

 tassium, in 2 million pounds of the surface soil (Frear, Penn. Dept. 

 Agr. Report, 1906). While most of the phosphorus is usually 

 soluble in the acid used (HC1 of 1.115 sp. 8 r -)> on ^y about one 

 sixth of the total potassium contained in old soils is thus dissolved, 

 as a general average, although the proportion varies greatly with 

 different types of soil. Doctor Frear has subsequently furnished 

 data showing that 2 million pounds of the fine earth in the surface 

 soil on the Pennsylvania State College farm contain 50,700 pounds 

 of total potassium. 



