SOIL 



Large amounts of water are necessary to 

 maintain the functions of plants due to rapid 

 evaporation from the extreme exposure of foli- 

 age, and the physiological processes, which de- 

 mand large movements of water in growing 

 tissues. The water capacity of soil is an im- 

 portant factor in determining its value for gar- 

 dening purposes. In general, the finer the soil- 

 grain the more soil-water will he held, and the 

 coarser the soil-grain, the greater the number of 

 spaces larger than capillary size, the less soil- 

 moisture will be held. It is necessary for the 

 best results to give constant and careful tillage 

 to secure the proper texture of soil. All water 

 which the soil may contain is not available to 

 plants. About half of their saturated amounts 

 must be drained away before soil can contain 

 enough air to maintain breathing of ordinary 

 roots and germinating seeds. A thorough water- 

 ing every few days is better than a slight appli- 

 cation every day. To prevent evaporation the 

 surface of the soil should be stirred to the depth 

 of three inches to make an effective earth mulch. 

 Firming the loose soil tends to increase mois- 

 ture in surface soil at the expense of the deeper 

 layers, and increases the rate of evaporation. 



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