CONCLUSIONS FROM EXPERIMENTS. 



69 



of rotations shows that in seven out of nineteen tests the corn rota- 

 tions (1 and 4) produced better crops of wheat and oats than the 

 sunimer-tilled rotations (5 and 8). In ten of the twelve tests where 

 the yields of wheat and oats were better on summer-tilled rotations 

 than on corn rotations the yield of corn was sufficient to more than 

 offset this difference. 



The two tests where the corn crop did not equal in value the gain 

 from summer tillage were Dalhart and Amarillo, Tex. In these tests 

 the crops of wheat and oats averaged only $1.91 and $4.49 per acre, 

 respectively. 



The average net gain of the com rotations over the summer-tilled 

 rotations for all tests was $4.08 per acre and the results were in 

 favor of the corn rotations in seventeen out of nineteen tests. (See 

 Table XXIV.) 



(10) Disking has given better average results than plowing corn 

 stubble as a preparation for wheat in eleven out of eighteen tests, 

 the net results being 36 cents per acre in favor of disking. (See 

 Table XXV.) 



(11) Fall plowing has given slightly better net results than spring 

 plowing. Local conditions of soil and climate influence the results 

 so profoundly that no general conclusions can be drawn. The 

 natural character of the soil, its physical condition at the time of 

 plowing, its liability to blowing during the fall and winter, and the 

 holding of snow by stubble during the winter must all be considered 

 for each farm and each season in determining the best time of plow- 

 ing. The most economical distribution of labor through the year is 

 also an important practical consideration. (See Tables XXVI and 

 XXVII.) 



(12) When summer tillage is introduced in a rotation containing 

 both wheat and oats, slightly better average results have been ob- 

 tained when oats follow summer tillage and wheat follows oats than 

 where wheat follows summer tillage and oats follow wheat. Local 

 conditions of soil and climate influence results in this respect to such 

 an extent that no general rule can be made to apply to all stations. 

 Certain stations give markedly better results from one sequence, 

 while others give much better results from the opposite sequence. 

 (See Table XXVIII.) 



(13) Where corn, wheat, and oats have been grown in a 3-year 

 rotation, better results have been obtained in twenty-four out of 

 thirty-five tests by following wheat after corn and corn after oats. 

 At Judith Basin, Mont., Highmore and Bellefourche, S. Dak., North 

 Platte, Nebr., and Amarillo, Tex., better results have been obtained 

 from the opposite sequence. The greatest advantage of the corn- 

 wheat-oats sequence was at Edgeley, N. Dak., in 1907, when it 



187 



