30 



TRANSPIRATION 



The loss of water from the soil when plants completely 

 cover the ground is chiefly through the plants. Generally, 

 weeds lower the moiuture more rapidly and to a lower limit 

 than coi*n (see discussion above). Plants also vary in the 

 amount of water required to produce a pound of dry matter. 

 Warrenton (Physieai Properties of Soils, 53) has colleeted 

 data which follows in Table XIV : 



Table XIV : Water Evaporated by Growing Plants for 

 One Part Dry Matter Produeed i 

 Results obtained by 

 Lawes and Gilbert Hellriegel King 

 Beans 214 Beans 262 Maize 



Peas 292 Barley 

 Barley 310 Potatoes 



^eat 225 

 Peas 235 

 Red Clover 249 

 Barley 262 



Red Clover 330 Red Clover 453 Sunflowers 490 



Wheat 359 Peas 



Buckwheat 371 Oats 



Lupine 373 



Rye 377 



Oats 402 



477 Buckwheat 646 



557 Oats 665 



Barley 774 



Mustard 843 



912 



