344 SOILS 



barely skimmed the soil; there is little intensive 

 farming in this country." 



The problem of worn-out soils is vital now and is 

 becoming more insistent as our agriculture ages. 

 Fortunately the East has at last awakened to the 

 exigencies of the situation, and is reclaiming her 

 worn-out soils with satisfactory results. It is to 

 be hoped that before the ricn farm soils in the 

 Mississippi Valley and westward have been brought 

 to the low productiveness that many Eastern soils 

 have now reached and they are surely trending 

 that way Western farmers will adopt me methods 

 of husbandry that are necessary to maintain 

 fertility. 



How to Begin the Work of Soil Improvement. 

 The methods that are of service in renovating worn- 

 out soils include all the points in soil management 

 that have been noted in the preceding chapters. 

 Undoubtedly there are a few worn-out soils that are 

 exhausted chemically: they are actually deficient 

 in plant food. But most of them are worn-out 

 physically. They are unproductive, because 

 they have been mismanaged. This mismanage- 

 ment may have consisted partly in bad handling, 

 such as plowing too shallow, or when the soil was 

 wet, or in not checking erosion. It is more likely, 

 however, to be due to mismanagement as regaras 

 rotation of crops; and probably it is due most of 

 all to mismanagement as regards maintaining the 

 supply of humus in the soil. Most worn-out soils 

 are in special need of humus. Green-manuring is 

 of greater importance in the renovation of worn- 

 out soils than any other factor. 



In most cases the quickest and easiest way, to 

 begin with, is to grow leguminous*crops for green- 

 manures. But green-manuring will be made more 



