152 THE CULTURE OF FARM CROPS. 



farm in different fields where the soil varies much in char- 

 acter ; and there is no crop that is grown which is not sub- 

 ject to modification in this respect. Even the amount of 

 organic matter in plants is affected by the differences of 

 soils; for some lands produce wheat much richer in gluten 

 than other kinds, and much above the average quantity 

 contained in this grain, and thus draw from the soil a lar- 

 ger quantity of nitrogen in which gluten is exceptionally 

 rich. Sweet corn is much richer in sugar, as is also sugar- 

 cane when grown upon lands rich in carbon, while pota- 

 toes grown upon reclaimed but well drained and dry- 

 swamp lands, rich in the same element, contain the largest 

 proportion of starch ; and onions grown upon the same soil 

 yield far more abundantly. 



These instances tend to show that the exhaustion of the 

 soil is not an element in the culture of crops that can be 

 figured out with precision, as is pretended by some persons, 

 and that it is therefore exceedingly unsafe and unwise for 

 the farmer to run close to the limits indicated by the fig- 

 ures. He must provide sufficiently for the demands of his 

 crops, as shown by the tables previously given, without de- 

 pending to any large extent upon the store which he has 

 reason to believe exists in the soil, and thus maintain a 

 large balance in hand to serve in cases of any possible and 

 unexpected exigencies. 



To sum up the interesting considerations which present 

 themselves in this regard, it may be stated ; 



First. That plants appropriate from the soil varying 

 quantities of inorganic, or ash, substances, as their age and 

 condition of grow r th may vary ; and that the different parts 

 of the plant draw from the soil, some more, and some less 

 of these substances than others. 



Second. That if the substances necessary for the growth 

 and perfection of one part of a plant more than another, 

 abound in any soil, the crop will be chiefly developed in 

 that direction; one will run to straw, another to leaf and so 

 on ; but as long as the crop can find food in the soil, it will 

 take it if only partially. 



