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of a considerable share of the elements of fertility which nature renders 

 soluble in the idle field. This sacrifice can be avoided if the soil be 

 kept occupied with the hungry rootlets of a growing crop, for they will 

 arrest the soluble elements in their downward course, and in the grow- 

 ing plant they will be converted into compounds of use and value. 



He who chooses to leave his field idle, but prevents production of 

 weed seeds by cutting, does far better than he whose field is the victim 

 of pure neglect ; but yet his labor is not directly productive. Even he 

 is made poor The rule of every good farmer should be " keep the 

 land covered with a growing crop at all times when season permits " 

 As soon as one crop is removed another should follow. 



The Selection of Catch-crops. 



The catch-crop, in so far as may be possible, should combine the fol- 

 lowing characteristics : cheap seed, ability to thrive when sown broad- 

 cast, rapid growth, freedom from qualities, either of root or seed, which 

 will cause it to become a troublesome weed, a deep vigorous root sys- 

 tem, the ability to take a part of its nitrogen from the air, hardiness in 

 winter (in the case of some), ability to stand frosts and to grow at a low 

 temperature, and value, either as a fodder or for soil improvement. 



The importance of these characteristics is in most cases perhaps evi- 

 dent ; but concerning some of these points a few words in explanation 

 seem desirable. 



The ability to thrive when sown broadcast is highly important, since 

 this is the quickest method of planting, and in most cases the farmer has 

 not much time that he is prepared to devote to the production of a catch- 

 crop. By this system, further, the weeds are more certainly and effect- 

 ually stifled than in the drill system. The farmer will not, as a rule, 

 wish to cultivate a catch-crop. 



The catch-crop must be one that will grow rapidly ; because, coming 

 between or after main crops, the time available is short. Further, the 

 rai)ld grower stifles and keeps down weeds while the slow grower, with- 

 out culture, is itself stifled. 



Some plants having most of the qualities above enumerated are yet 

 unfit for catch-crops because they have vigorous root stocks ; others it 

 would be unwise to select because of the abundance of seed which would 

 lie uninjured in the ground over winter or for many years. 



A' deep and vigorous root system enables the crop to gather abundance 

 of food even from soils not very fertile. It makes a crop a good rustler, 

 to use the expressive western term ; and it is the rustler which thrives 

 without special attention to manuring and culture. These the farmer 

 will not care to give to catch-crops in the majority of instances ; hence 

 the importance of this characteristic. 



Often an important object in the introduction of catch-crops is the im- 

 provement of the soil. Those crops which can assimihde atnwsphcric 

 nitrogeji serve this purpose most eftectually. Other crops return to the 

 soil only that nitrogen which they first take from it ; and the soil cannot 

 be enriched in this element by their growth. True, the culture of almost 



