*)2 CLOVER CULTURE. 



tion of the nitrogen is usually first, for the reason that this 

 most costly element is more easily washed out of the soil by 

 rains during that part of the summer season when it is not 

 covered with some kind of growing crop. There are other 

 reasons, in addition to the failure in the supply ot nitrogen, 

 that prevents continuous cropping by the same plant. A nota- 

 ble instance of this is the refusal of even the best corn lands in 

 the West to grow profitable corn crops in succession for very 

 many years. The corn - root worm ( Diabrotica Longi- 

 tornis] ki many portions of the West begins its operations in 

 a small way the first year. The damage is more noticeable 

 the second and third years, and wherever this pest has made 

 its appearance it usually reduces the crop below what should 

 be regarded as a paying basis. 



Long continued growth of successive crops of winter 

 wheat on the same land gives every opportunity for the in- 

 crease of the Hessian fly, which lays its eggs in the volunteer 

 crop that springs up after harvest. The smuts, rusts and 

 other fungus diseases multiply rapidly when a large acreage 

 of spring and winter wheat is sown in the same vicinity, and 

 especially when sown repeatedly upon the same lands. It is 

 only a question of time when Nature comes in with her im- 

 perative command, "Rotate or cease to grow profitable 

 crops. ' ' 



A rotation, to be profitable, must embody several distinct 

 features. It must comprise crops that mature in different 

 seasons of. the year in order that the labor of the farm may 

 find profitable employment. This is imperative. It should 

 consist of crops for which the ground can be prepared and the 

 planting done at different periods of the year. It should con- 

 sist of crops that draw as far as possible on different elements 

 ot fertility in the soil, and if possible, of some crop which re- 

 stores the elements of fertility which have been exhausted by 

 other crops. It should embrace both grain crops and forage 

 crops. And finaWy, it should consist of one or more cleaning 

 oops; that is, crops that either smother out weeds or furnish 

 ample opportunity for destroying them in the cultivation de- 

 manded , for other reasons, by the crop. For the above reas- 

 ons, rotations wherever adopted should contain as far as pos- 

 .sible grain crops, grass crops and hoed crops, by the latter 

 being meant such crops as require tillage in some form during 

 their period of growth, as for instance, corn and potatoes in 

 America, and potatoes, turnips, mangels, beets, etc., in Bu- 

 xope. As all ordinary rotations must necessarily contain 



