SOIL FERTILITY 



gardener thrifty, the top-soil of paths, as they are 

 made or cleaned, is thrown on the beds and made 

 in some measure to replace soil that has been 

 worn out or removed by adhering to the roots of 

 weeds and rubbish. A vegetable garden can be 

 built up on four inches of top-soil by avoiding deep 

 root crops and by frequent fertilization to replace 

 exhausted plant food. A flower garden, carefully 

 selected for shallow running roots, can be built 

 upon less depth. But grains require more as they 

 send their roots from two to four feet deep and 

 corn requires even six feet. It is therefore essen- 

 tial to recognize and conserve this top layer of 

 soil. 



Finely divided soil may, as in the case of soils 

 of reasonable fertility and lightness, be obtained 

 by a mere mechanical division and multiplication 

 of particles, by ploughing, harrowing or by deep 

 spading and raking. If an experienced plough- 

 man is not to be had, and the area permits, 

 by all means thoroughly spade it. Land should 

 be prepared in the fall. It should be ploughed 

 evenly, deeply and carefully, turning in well rotted 

 manure that has been spread about three inches 

 deep. This depth of manure is necessary for the 

 rich soil demanded in a school garden, where the 

 same soil may be required to carry successive crops 

 in one season. Ten cords to the acre is a farm 

 i\erage, and spreads a layer of one-quarter of an 

 inch. Market gardens often use from 25 to 30 

 cords; truck farmers on small areas use still more. 



89 



