204 LAND DRAINAGE 



270. Crop needs. McGee says, " In ordinary farm- 

 ing, the agricultural duty of water is to produce one 

 thousandth of its weight in useful crops " and " on ordi- 

 nary soils the water required for full productivity is about 

 60 inches (5 feet) per year." 1 



England leads the nations in acre yields of grains. 

 The average yield of wheat (1902-1911 inclusive) was 

 33 Winchester bushels (41.25 American bushels) to the 

 acre. 



B. C. Wallis says, " In England wheat is not grown well 

 where the -rainfall exceeds thirty inches," and again, 

 " As regards rainfall, the annual precipitation of Ohio is 

 greater than that of Cheshire " (England). The maxi- 

 mum average yield of wheat in Ohio for any year 1870- 

 1911, occurred in 1910, and was 16.2 bushels to the acre. 2 

 Undoubtedly during the same period there occurred, in 

 Ohio, individual yields exceeding 40 bushels to the acre, 

 indicating the possibilities with present actual rainfall. 



According to King, 12 acre-inches, under the most 

 favorable conditions, may be expected to produce 40 

 bushels of wheat to the acre. It would produce over 70 

 bushels of corn, or about 78 bushels of oats, or about 55 

 bushels of barley to the acre. 3 These citations are made 

 to show the range of possible water service, in ordinary, 

 good, and ideal practice in crop production. 



271. Animal needs. The average adult person prob- 

 ably uses less than one ton of water per annum for food 

 and drink. Assuming that he used a barrel of water a 



1 Subsoil Water of Central United States, Yearbook, 1911, pp. 

 479-490. Also the Agricultural Duty of Water, Yearbook 1910, 

 pp. 169-175. 



2 Yearbook, 1911, p. 535. 



3 King's Physics of Agriculture, p. 141. 



