246 SOILS: PROPERTIES AND MANAGEMENT 



Water Requirements of Plants by Different 

 Investigators 



Crop 





- ' - 



te w z 



5 o •< 



1 « J 



Barley . 

 Beans 

 Buckwheat 

 Clover . 

 Maize 

 MiUet . 

 Oats 

 Peas 

 Potatoes 

 Rape 

 Rye . . 

 Wheat . 



H 



258 

 209 



269 



259 



247 



[m B'-l 



774 



646 



233 

 447 

 665 

 416 



912 



w O 



310 

 282 

 363 

 310 



376 

 273 



353 

 338 





464 



576 

 271 



503 



477 

 385 



M 



3 



468 



337 



469 

 563 



544 



< SO 05 



534 

 736 

 578 

 797 

 368 

 310 

 597 

 788 

 636 

 441 

 685 

 513 



1 Lawes, J. B. Experimental Investigation into the Amount 

 of Water Given off by 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 

 unfertilized soil. 



2 Wollny, E. Der Einfluss der Pflanzendecke und Beschat- 

 lung auf die Physikalischen Eigenschaften und die Frucht- 

 barkeit des Bodens, Seite 125. Berlin, 1877. 



Wollny grew plants in humous sand in amounts ranging from 

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

 degree by perforated covers. Actual evaporation from un- 

 cropped cans was observed, however. 



3 Hellriegel, H. Beitrage zur den Naturwissenschaftlichen 

 Grundlagen des Ackerbaus, Seite 663. Braunschweig, 1883. 



Hellriegel grew plants in 4 kilograms of clean quartz sand 

 and supplied them with nutrient solutions. The loss by evap- 

 oration from uncropped pots was used in determining losses 



