CLEAN CULTURE THE SECRET OF SUCCESS. 317 



We apply a quantity of manure to a piece land, for the pur- 

 pose of supplying the necessary food to grow a crop. By this act 

 we have invested in this piece of land a certain sum of money 

 in labor, use of tlie land and fertihzers. Now, suppose we 

 neglect to keep down the weeds ; they absorb from the soil the 

 fertilizers that we have been at so much expense to procure and 

 apply, and these weeds, by their roots seize upon and take 

 probably that very portion of manure, already soluble, and in 

 the best condition for plant-food, which the expected crop 

 then trying to establish or perfect itself may at this very time 

 require. Our idea is this : that the manure becomes soluble 

 and fitted for plant-food by degrees, and not all at the same 

 time; and that portion which becomes soluble first is seized upon 

 by the weeds, if they are allowed to grow, to the detriment of 

 the crop, which oftentimes may need it at that particular time, 

 to either establish or perfect itself. 



Now, if this is so, and by any carelessness or neglect we 

 allow the weeds to grow and overrun our crop, we should cer- 

 tainly fail to get any income from the investment we have made 

 in labor, manure and use of the land. And therefore we can 

 say that clean culture is one of the"important things to be prac- 

 tised in farming; and in this branch of the business it becomes 

 indispensable, and without it there can be no great success. 



ROTATION OP CROPS IN GARDEN CULTURE. 



There are two theories in regard to the failure or depreciation 

 of the same crops where grown year after year on the same piece 

 of land. 



One of them is this, that plants exude from their roots excre- 

 ments which render the soil unfit to a certain degree to grow 

 the same variety of plants, until by a lapse of years that delete- 

 rious property has become neutralized. The other is, that plants 

 exhaust particular elements from the soil, necessary for their 

 growth, and that by supplying or returning the substances ex- 

 hausted to the soil, the same variety can be grown indefinitely 

 on the same piece of land. Both of these theories are advo- 

 cated by scientific men, eminent as botanists and chemists, and 

 they give plausible reasons on both sides in support of their 

 respective views. 



Now without undortakinsr to discuss these theories, which is 



