THE ADVANTAGES OF A ROTATION OF CROPS. 259 



may be much increased by plowing and harrowing the land and 

 let the grass again occupy the soil. This plan is especially well 

 adapted to renewing the yield of June grass, quack grass, Ber- 

 muda grass, and Johnson grass. 



In reference to permanent grass lands, J. Julie, of England, 

 in his "Gold Medal" essay, makes the following remarks in 

 Jour. Eoy. Ag. Soc. for 1882 : " The cultivation of roots and 

 cereals deprives the soil of nitrogen, whilst that of grass and 

 leguminous plants, temporary or permanent, on the contrary 

 causes it to accumulate in the soil. That nitrogen being the 

 most expensive to buy, it is not economical to devote part of the 

 land absolutely to arable and part to grass, for whilst the one 

 uses up the nitrogen, the other accumulates it in excess. It is 

 preferable to alternate on the same piece of land the cultivation 

 of roots and cereals with that of grass lays. By this means 

 cultivation can be kept up indefinitely without purchasing 

 nitrogen, provided the land be maintained in a fit state of rich- 

 ness as regards the mineral elements. The occupation of land 

 by a grass for two or three years which takes its turn in the 

 rotation of crops is preferred to permanent occupation by grass." 



The late J. J. Mechi, of England, objects to old pastures in 

 countries which are rather dry. The crop is too light ; arable 

 la"nd is more profitable. 



The Advantages of a Rotation of Crops. Some of them are 

 as follows: Manure is economized, as crops do not all feed alike; 

 the fertility of the soil is better and more economically preserved ; 

 weeds are more easily controlled ; it enables a person to distribute 

 his labor more evenly through the year ; it gives a proportion of 

 grain for feed and coarse straw for litter ; crops in alternation 

 are less liable to the attacks of fungi and insects. Where fields 

 are occasionally cultivated, moles are less likely to become 

 troublesome. Leguminous plants are not specially benefited by 

 nitrogenous manures, but they are nitrogen "producers," and 



