58 THE UNIVERSITY OF OKLAHOMA 



TABLE 2 



Average 5 years 



Treatment Grain (bushels) Straw (pounds) 



Manure and Continuous Culture 45.70 1669.6 



Rotation alone 46.89 1804.2 



In making a comparison of the effects of manure it is readily 

 observed that manure whether used in a rotation or in continuous 

 culture gives a good return. The average for manure in continu- 

 ous culture is 1462.4 pounds or 45.70 bushels of grain and 1669.6 

 pounds of straw per acre. When this is compared with the effects 

 of rotation alone it becomes evident that the rotation alone has 

 been more effective in maintaining the yields of oats than has 

 manure when used in the continuous culture. 



TABLE 3. 



Yields 

 Average S Years 



Treatment Grain (bushels) Straw (pounds) 



Manure and Continuous Culture 45.70 1669.6 



Manure and Ratation 48.28 1736.5 



Check Plots Continuous Culture Average)— 39.58 _ 1460.2 



Table 3 also shows a comparison of the poorest yields which 

 were obtained by continuous culture alone and the best yields 

 which were obtained by using manure in connection with a crop 

 rotation. The table shows a difference of 8.7 bushels of grain and 

 276.3 pounds of straw in favor of the rotation and manure. 



Crop residues are especially helpful in maintaining the yields 

 of oats when grown continuously oh the same land. Residues have 

 not shown up so well where used in a rotation so far, but may 

 show to advantage later on when the experiment has been con- 

 ducted longer. Table 4 shows a summary of the different methods 

 used in connection with continiious culture. 



TABLE 4. 



Yields of Grain per acre 

 Treatment Average 5 years 



Check Continuous Culture 39.58 Bushels 



Residues Continuous Culture 43.38 Bushels 



Manure Continuous Culture 45.70 Bushels 



It is ititeresting to compare the results obtained for the vari- 

 ous methods used in the continuous culture (Table 4) with those 

 obtained with the rotation (Table 5). 



TABLE 5. 



Yields of Grain per acre 

 Treatment Average 5 years 



Check plot Rotation 46.89 Bushels 



Residues and Rotation 45.90 Bushels 



Manure and Rotation . 48.28 Bushels 



Any of the methods when used in connection with a rotation is 

 better than the best method (manure) followed in the continuous 

 cropping system. 



Another point that should be noted is the yields of the crops 

 at the beginning of the experiment as compared with the 1921 yields. 

 Table 6 will help bring out this comparison. 



