68 CULTIVATION METHODS AND [ROTATIONS FOR GEEAT PLAINS. 



the total loss of the crop where extreme drought is anticipated, but 

 it can not be depended upon to produce as profitable crops under 

 average normal conditions as may be produced by other methods. 

 (See Tables I, II, III, XXI, and XXIII.) 



(2) Continuous cropping with moisture-conservation methods, in- 

 volving early fall plowing and thorough fall, winter, and spring tillage 

 and harrowing after the grain is up in the spring, has not given aver- 

 age results to warrant its practice. There have, however, been a few 

 exceptions to this rule. (See Tables I, II, III, XXI, and XXIII.) 



(3) A simple 3-year rotation of corn, wheat, and oats has given 

 more profitable returns than any method of continuous cropping or 

 alternate cropping and summer tillage in fourteen out of seventeen 

 tests. In the three instances where continuous cropping gave better 

 returns the difference was so small as to be practically negligible. 

 (See Table XXIII and the preceding tables, of which it is a summary.) 



(4) The two 3-year rotations giving the best average results are 

 No. 1 (wheat on disked corn ground, oats on fall plowing, corn on fall 

 plowing) and No. 6 (barley on disked corn ground, oats on fall plowing, 

 corn on fall plowing) . These two rotations are identical except that 

 barley has been substituted for wheat in No. 6. One or the other 

 of these two rotations gave the best results at nine of the eighteen 

 tests: Dickinson, N. Dak., 1909, Edgeley, N. Dak., 1907 and 1908, 

 Highmore, S. Dak., 1907, Bellefourche, S. Dak., 1909, North Platte, 

 Nebr., 1908, Akron, Colo., 1909, Hays, Kans., 1908, and Amarillo, 

 Tex., 1908. (See Table XXIII.) 



(5) Rotation No. 7, oats, barley, corn, all on spring-plowed land, 

 gave the best results at three tests: Highmore, S. Dak., 1908, North 

 Platte, Nebr., 1909, and Garden City, Kans., 1909. (See Table 

 XXIII.) 



(6) Rotation No. 3 (wheat, oats, corn, all on fall plowing) and 

 rotation No. 4 (oats on disked corn ground, wheat on fall plowing, 

 corn onfall plowing) each gave the best results at two tests: Edgeley, 

 N. Dak., 1909, and Amarillo, Tex., 1909, for No. 3; Judith Basin, 

 Mont., 1909, and North Platte, Nebr., 1907, for No. 4. (See Table 

 XXIII.) 



(7) Rotation No. 2 (wheat, oats, corn, all on spring plowing) gave 

 the best results at only one test, Dickinson, N. Dak., 1908. (See 

 Table XXIII.) 



(8) Rotation No. 9 (oats, wheat, corn, all on spring plowing) failed 

 to give the best results at any test and averaged 42 cents per acre 

 poorer than continuous cropping. (See Table XXIII.) 



(9) Summer tillage had been introduced in rotations Nos. 5 and 8 

 in place of corn. These two rotations are otherwise identical with 

 rotations Nos. 1 and 4, respectively. A comparison of these two pairs 



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