A SIMPLE CHANGE 05 CROPS NOT ALWAYS BENEFICIAL 271 

 Crop Rotation Increased the Yield of Winter Wheat, ^ 







i\ erage 

 annual j-ield 



Average 

 annual yield 



Decrease and 

 mcieasp in 



Cropping sj stem 



Fertiliaer tieatment 



per a,cre for 



for the third 



1 T VP>fl,r«! 







period 



5-year period 



(per cent) 







1894-1898 



190i-190S 







Bushels 



BiLsheU 





Wheat continuous!} 



No treatment 



10 08 



6 19 



38 decrease 



Wheat in 5->ear 











rotation 



No treatment 



9.28 



13.66 



47 increase § 



Wheat continuously 



Fertilizers 











(mixed) t 



19 78 



17.41 



12 decrease 



Wheat in 5-year 



Feitilizers 









rotation 



(mixed) t 



20 53 



33 10 



61 mcrease 



^ Ohio Experiment Station bulletin 231, 1911 



t One hundred sixty pounds each of acid phosphate and nitrate of soda, and 100 pounds 

 of muria.te of potash applied annually to the wheat crop 



X Fertihzers applied 3 times m each S-jear period — SO pounds each of acid phosphate 

 and muriate of potash to each corn and oat crop, and each v^heat crop received the same 

 treatment as given each ti op of v, heat m continuous culture 



S It cannot be assumed that this increase on the unfertihzed plot will con- 

 tinue indefinitely 



Under the conditions of this experiment^ rotation of crops is 

 much more favorable to the growing of winter wheat than continu- 

 ous cropping when yield and economy of production are considered. 



Rotation Can Not Take the Place of Fertilizers. — ^Though 

 a proper rotation is a most important farm practice to aid in main- 

 taining and increasing soil fertility, yet it cannot take the place 

 of manure and commercial fertilizers. "Whenever crop rotation 

 without fertihzation increases the productivity of a soU, it is only 

 temporary; because when the yields are thus increased, the draft 

 upon the plant-food elements becomes greater, and this tends 

 towards more rapid soil depletion. It becomes more urgent, 

 therefore, to practice rational fertihzation in order to secure the 

 best results from rotations. The results in the tables, pages 270 

 and 271 emphasize this fact. 



Rotation Only One of Several Factors in Maintaining Fertility. 

 — ^It is well to keep in mind the several factors involved in main- 

 taining soil fertility, which are: (a) Thorough drainage; (5) proper 

 tillage; (c) crop rotation; {d) liming; {e) a rational use of manm-e 

 and commercial fertihzers, and (f) green manuring. 



A Simple Change of Crops Hot Always Beneficial. — Farmers 

 have observed, and soil investigators have demonstrated, that a 

 simple change of crops may not always prove beneficial. In some 

 sections farmers experience unsatisfactory corn crops when grown 

 after sugar beets. The North Dakota Station has found that on 



