WATER OF SOIL IN ITS RELATION TO PLANTS 189 



Table XXXIV 



WATER REQUIREMENTS OF PLANTS AS DETERMINED BY DIFFER- 

 ENT INVESTIGATORS. 



Ceop 



-- 



Lawes ^ 

 Harpen- 



DEN, 



England, 

 1850 



WOLLNY ^ 



Munich, 



Germany 



1876 



Barley . . . 

 Beans . . . . 

 Buckwheat 

 Clover . . . 

 jLYiaize . . . . 



Millet 



Oats 



Peas 



Potatoes . . 

 Rape . . . . 



Rye 



Wheat . . . 



258 

 209 



269 



259 



247 



774 

 646 

 233 



-4.4.7 



665 

 416 



912 



Hell- 



eiegel ^ 



Dahme, 



Germany 



1883 



King* 



MA0ISON, 



Wis., 1895 



JiEATHBE " 

 P0SA, 



India 

 1911 



310 

 282 

 363 

 310 



376 

 273 



353 

 338 



464 



576 

 271 



503 



477 

 385 



468 



337 



469 

 563 



544 



Briggs 



and 



Shantz" 



Akron, 



Colo. 

 1911-1913 



534 

 736 



578 

 797 

 368 

 310 

 597 

 788 

 636 

 441 

 685 

 513 



^ Lawes, J. B., Expenmental Investigation into the Amount of Water 

 Given off hy Plants during their Growth; Jour. Hort. Soc, London, 

 Vol 5, pp. 38-63, 1850. Pots holding 42 pounds of field soil were used. 

 Evaporation from soil was reduced to a very low degree by perforated 

 glass covers cemented on the pots. The figures quoted are from un- 

 fertilized soil. 



^ WoUnj, E.j Der Etnfluss der FflansendecTce und Beschattung auf die 

 FhysiTcalischen Bigen^chaften und die FruchtharJceit des Bodens, Seite 

 125; Berlin, 1877. Wollny grew plants in sand in amounts ranging 

 from 5 to 12 kilograms. Evaporation was reduced to a very low 

 degree by perforated covers. Actual evaporation from uncropped cans 

 was observed, however. 



'Hellriegel, H., Beitrdge sur den NaturwissenschaftUchen Grundlag&n 

 des Ackeriaus, Seite 663; Braunschweig, 1883. Hellriegel grew plants 

 in 4 kilograms of clean quartz sand and supplied them with nutrient 

 solutions. The loss by evaporation from uncropped pots was used in 

 determining losses by transpiration. In later experiments covers were 

 used in order to cut down evaporation. 



^King, F. H., Physics of Agriculture, p. 139; published by author, 

 Madison, Wis., 1910. Also, The Number of Inches of Water Bequired 

 for a Ton of Dry Matter in Wisconsin; Wis. Agr. Exp. Sta., 11th Ann. 

 Bep., pp. 240-248, 1894 ; and The Importance of the Bight Amount and 

 Bight Distribution of Water in Crop Production; Wis. Agr, Exp, Sta,, 



