EXPERIMENT STATION BULLETINS. 



525 



destroyed. This is illustrated by the run-out condition of the soil of the 

 Wetmore area in Alger county. 



THE PRINCIPLES OF A GOOD ROTATION. 



The various classes of farm crops, by virtue of their different types 

 of root systems and their different composition, do not remove the same 

 elements in like amounts or from the same level in the soil, therefore, 

 by changing from field to field with different classes of crops, a bene- 

 ficial effect is apparent as compared to the one crop system. The hay 

 crops because of their elaborate root system and sod formation aid in 

 the upkeep of the organic matter of the soil. The legumes because of 

 their ability to store nitrogen in the soil should be included in the rota- 

 tion. A cultivated crop should be included to aid in weed control and 

 to aerate the soil properly. 



A rotation to meet these requirements would include the following: 



First: A legume hay crop (clover, alfalfa, sweet clover) 



Second: A cultivated crop (potatoes, sunflowers, root crop, corn, 



sugar beets) 

 Third: A small grain crop (oats, barley, wheat, rye). 





Fis. 18. Summer fallowing is advised where trouble is experienced with quack-grass. This 

 also prepares excellent seed bed for fall graias. 



WHEN TO API'LY LIME^ MANURE AND FERTILIZERS IN THE 'ROTATION. 



Lime where needed sliould be applied in fitting the seed bed the 

 season preceding the hay crop. Manure should be applied as a tojj 

 dressing on the meadow or applied to the sod the season preceding the 

 cultivated crop. 



