TILLAGE 



25 



Subsurface packing is another important feature of dry 

 farming. It is done by means of specially made heavy 

 implements that are drawn over the field and pack the 

 lower part of the furrow slice, but leave the surface mellow 

 and loose. This packing increases the capacity of the soil 

 to hold moisture, and packs the furrow slice against the 

 subsoil so that any moisture in the subsoil may be brought 

 up into the furrow slice by capillarity. 



A surface mulch consists of from two to four inches of 

 loose, fine soil over the surface of the field. It is main- 



iV^y.. .'■ 



Figure 9. A subsurface packer. 



tained by persistent disking and harrowing. Every rain 

 packs this surface soil down, and, if left packed down, the 

 moisture in the lower part of the furrow slice or in the 

 subsoil will be raised to the surface by capillarity. If 

 brought to the surface the sun and wind will evaporate it, 

 and it will be lost. Harrowing at once after a rain loosens 

 up this surface soil, making of it a surface mulch through 

 which the moisture cannot rise. 

 Questions: 



1. What do you understand by the term, "dry farming"? 



2. What is the reason for deep plowing in dry farming? 



3. What do you mean by the term, "surface mulch"? Of what 

 use is it? How is it maintained? 



