152 SCIENCE AND SOIL 



cases, in the author's opinion it is a matter which has been given 

 undue consideration in comparison with other extremely important 

 factors. 



Even in the common practice of agriculture, soils at first well 

 adapted to the growing of a certain crop do not remain so adapted. 

 The fact is too well known to need illustration that specific crops 

 are often grown with success for years finally to fail and be aban- 

 doned for some other successful crops, which in turn finally give 

 way to others. Thus good wheat land finally becomes poor wheat 

 land, but still remains good for timothy hay, which in turn gives 

 way to red top, and this may be followed by partial abandonment 

 of the land for crop production. 



At any stage in this process of soil depletion, the land may be 

 restored to its original power to produce wheat, by adopting the 

 proper systems of soil enrichment. 



When land refuses longer to grow any crop which it has formerly 

 produced with satisfaction and profit, the landowner should, as 

 a very general rule, find out what the trouble is, and then proceed 

 to remedy it; but, instead of meeting and overcoming such diffi- 

 culties, the American farmer has literally run away from them; 

 either by seeking newer lands or by adopting any other crop which 

 the land would still produce. 



The most common staple crops can be grown on almost any soil 

 if it is well drained, well watered, and sufficiently rich. Of course, 

 the matter of crop adaptation must not be ignored, but if we would 

 grow either plants or animals, we must not neglect the food supply. 



