THE SOIL AND WATER 123 



In some pot experiments of Konig, similar results were secured. 

 The relative quantity of crop he produced on three soils was 

 100:122:134, while the relative transpiration of water was 

 100 : 74 : 63, being in the opposite direction. Gardner 1 found in 

 wire basket experiments, that as fertilizers increase plant growth, 

 there is a marked diminution in water transpired per unit of 

 growth. 



It would appear that a fertile soil conserves moisture, so far as 

 transpiration is concerned, much better than a poor one. That 

 is to say, the better supplied a soil is with plant food, the larger 

 is the crop which it can produce with a limited supply of water. 

 The presence of plant food results in an economy of water. The 

 smaller the quantity of available plant food present, the greater 

 seems to be the effort made by the plant to secure sufficient plant 

 food, by increasing the current of water passing through it. 



Results of an experiment with corn on soil types at the 

 Nebraska 2 Experiment Station, are as follows : 



Variety of Plant. The difference in the transpiration of differ- 

 ent kinds of plants is probably a factor in the adaptability of 

 plants to climate and soils. Plants which live in dry regions, 

 such as cactus, salt bush, etc., transpire less water than plants 

 adapted to moist sections. There are other causes of endurance 

 of drought, however, such as the deeper rooting already dis- 

 cussed. 



According to Fittbogen there is no relation between transpira- 

 tion and the production of organic substance, as measured by the 

 carbon dioxide decomposed. 



1 Bureau of Soils, Bull. 48. 



2 Proc. Am. Soc. Agri., 1911, p. 277. 



