292 



Illinois State Dairymen s Association. 



so frequently done. Crops of rye, or preferably legumes, should 

 be grown and turned under to increase the organic content and at 

 the same time augment the scanty supply of nitrogen in these 

 soils. A crop of cowpeas or clover is not wasted if plowed under. 

 The increased yield of the succeeding crops may more than pay 

 for it. The turning under of cover crops will help increase the 

 organic matter, but this is too slow on land that is washing. Oine 

 or two entire crops in a four-year rotation should be plowed under 

 for a time at least. 



All forms of organic matter are about equally important to 

 the soil from a physical standpoint, yet legumes are much more 

 valuable because of the large amount of nitrogen which they con- 

 tain. A ton of corn stalks contains 16 pounds of nitrogen, oat 

 straw 12, wheat straw 10, clover 40 and cowpeas 43 pounds. The 

 soil being deficient in nitrogen it would be much better to turn 

 under clover and cowpeas than other forms. Even if a soil has a 

 good store of organic matter to begin with, it does not require a 

 great many years of cropping to reduce that stock below what it 

 should be. A 50 bushel crop of corn requires 74 pounds of nitro- 

 gen to produce it. About 1,500 pounds of average organic matter 

 must be decomposed and lost to the soil to provide this nitrogen. 

 If the average amount of organic matter in the surface seven 

 inches is 2 per cent, or 20 tons per acre, twenty-seven 50-bushel 

 crops would require all of it to be decomposed to furnish nitrogen, 

 provided the stalks were removed or burned. This rapid de- 

 pletion of organic matter by cropping is aided materially by wash- 

 ing and soon reduces the soil to a condition of unproductiveness. 

 Every means must be employed to maintain the supply. The 

 amount of washing is proportional to the loss of organic matter. 

 The more the soil is "run down" the more difficult it is to grow 

 cover and soil renovating crops. (See Bulletin 115). 



3. Tillage. — Probably nothing that we can do to rolling 

 land will give greater results, either for good or bad, than the 

 methods of tillage practiced. The farmers of Illinois have not yet 

 learned the importance of this. The direction of plowing, planting 

 and cultivation is usually determined only by convenience and 

 regardless, too often, of consequences. We should learn to look 

 not only to the present, but also to the future of our soils. Plow- 

 ing is more frequently done up and down the hill in this state 

 than in any other way. The making of dead furrows in this 



