AGRICULTURE. 473 



its proper position while growing. If a soil be so shallow or so hard that the 

 roots can not penetrate to a sufficient depth, the plant would be uprooted by 

 the first winds that spring up. Or if the soil is so loose that the roots are 

 easily drawn out, the same results will follow. Soils may be improved in 

 these particulars by cultivation, which will be noticed more fully in another 

 place. 



The next important quality of soil to be noticed is its capacity to absorb 

 and retain moisture. This is probably of more importance in Northwestern 

 Texas agriculture than any other quality, and one that ought to have more 

 than ordinary consideration. 



In the growing plant water constitutes a large part of its substance. The 

 organic material on which the plant feeds is held in solution in the water, 

 and is taken up and conveyed by absorption to the various parts of the plant 

 and there assimilated. There are also materials not necessary to the plant 

 life held in solution, which if retained in the plant would prove deleterious to 

 its growth. A certain amount of water is thrown off by the plant, and with 

 that water is excreted the unnecessary organic matter. A great deal more 

 water is exhaled by the growing plant than is returned to the soil by rains 

 and dew during the period of growth. The plant will therefore be dependent 

 upon the water stored up from previous rains for its supply of moisture. 

 That soil which absorbs the greatest amount of water will not, however, al- 

 ways be most productive, for there are several other things to be taken into 

 consideration. Some soils absorb moisture very readily in large amounts, 

 but are not productive because from their physical properties they permit the 

 water to pass beyond the reach of the roots of the plants or they steadily 

 give off their moisture in the form of vapor. The ability of a soil to retain 

 moisture against these influences is determined by the size of the material 

 going to make up the soil. 



The power to absorb moisture by the various ingredients making up the 

 soil are as follows: Siliceous sand, 0; sandy clay, 28; carbonate of magnesia, 

 90; gypsum, 1; loamy clay, 34; humus, 110; calcareous sand, 3; pure clay, 

 48; slaty marl, 35; common soil, 23; carbonate of lime, 35. 



The addition of vegetable material will always increase the capacity of a 

 soil to receive moisture. The power to receive and retain moisture by a soil 

 is almost in the same ratio. 



Another important factor of good soil is its power to receive and transmit 

 heat. The color and texture of a soil have much to do with its power to ab- 

 sorb heat. The dark lands absorb heat much more rapidly than those of a 

 lighter color. Sandy soils absorb much more heat than clayey soils. Yet 

 clayey soils give off their heat much more rapidly than sandy soils. A proper 

 analysis of the soils of the State will enable those who desire such informa- 



