ARID AGRICULTURE. 45 



that are plowed deep come more rapidly into 

 good tilth. Fining the soil particles releases and 

 makes available plant food. It lets in warmth 

 and air and gives better chance for the activitv 

 of chemical agents and bacteria. 



PLOWING ^ ie * ar er P art ^ soluble plant food becomes 



GIVES BOOT available in the surface soil. Plant roots pass 

 PASTURE thru it easily and here they send out their feed- 



ers to make use of the foods ready for them. If 

 four inches of the surface soil i e kept stirred for 

 mulch the difference between plowing seven 

 inches deep and eight inches deep equals twenty- 

 five per cent in the area of the surface soil upon 

 which the roots feed. 



DEEP Where the soils are light and winds drift 



PLOWING 



SAVES THE them, .-hallow plowing may result in all the top 

 sorL soil, down to the sole of the furrow being blown 



away. Deep plowing on the contrary, thrmv- 

 up heavier and rougher furrows, and tends to 

 anchor the soil in place. Plowing deep, there- 

 fore, both prevents washing and drifting. 



PLOWING EEP Wnere s ^l s are heavy, it often happens that 

 MAY NOT DO ^ly an inch or two of the surface is in condition 

 for the growth of plants. Turning this surface 

 ->il under and covering it deeply with cold, un- 

 tamed and unproductive clay, may prevent rais- 

 ing a good crop for longer time than it is desira- 

 ble to wait. This seldom occurs in dry farming, 

 for the summer fallow will tend to put the soil 



