DRY FARMING CONGRESS. 



75 



per acre, thus showing that the- variation of yield within the groups, both 

 in the first and in the second part of the table, is greater than the difference 

 between the average yields of the groups as arranged. 



The extreme range in yields in the spring plowed group of the first 

 part of the table is 3.7 bushels per acre. The extreme range of the fall 

 plowed group is 7.6 bushels. The range in the disced corn group is 6.4 

 bushels. As has been mentioned, the range in the summer tilled group is 

 5.8 bushels. Taking these figures as just given, we find that the average 

 range of yields within the four groups is 5.8, while the greatest difference 

 between the averages of the two extreme groups, spring plowing and 

 summer tillage is almost exactly the same, that is 5.8 bushels per acre. 



In the summar}' we find that one fall plowed plat of wheat land gave 

 a yield of 26 bushels per acre, while the average yield obtained from the 

 two fall plowed plats on oat land was 2§.3 bushels per acre, but as already 

 noted, the two fall plowed plats of oat land gave yields of 24.2 and 28.3 

 bushels per acre, respectively. Now. if we compare our 26 bushel yield, 

 obtained from the fall plowed wheat plat with the 24.2 bushel yield of the 

 fall plowed oat plat, we come to the conclusion that continuous cropping 

 to wheat gives a yield of 1.8 bushels per acre more than following wheat 

 after oats. If, on the other hand, we compare the yield from our fall 

 plowed wheat plat with that of the other fall plowed oat plat, which gave 

 28.3 bushels per acre, we come to just the opposite conclusion, which is 

 that following wheat after oats gives 2.3 bushels more than continuous 

 cropping to wheat. 



We might continue this kind of regrouping and cross checking in- 

 definitel}', but I think that enough has been said to indicate the dangers 

 of too much generalization, from a too limited observation. 



AVe find that our figures instead of not proving enough, prove altogether 

 too much. We find, to use ^Ir. Crother's expression, that we have discov- 

 ered a large number of "little unclassified truths that drive us to our wits' 

 end." There they stand, each in its shameless actuality, asking, "What do you 

 propose to do with me?" Mr. Crothers suggests that at this stage it is 

 the mission of humor to appear upon the scene and convert these incon- 

 gruities into pure joy. I think, however, that we can devote them to a 

 much better purpose, although we are not disposed to deprive ourselves 

 or anj'one else of any of the joy that they may be able to derive from 

 them. I think that these facts which refuse to be classified according to 

 an}' system 3^et established do not indicate that they cannot be systematized, 

 but simply show us that no system has yet been devised that will fit all of 

 the facts; that in attempting to draw conclusions based upon the considera- 

 tion of only the facts of tillage and crop sequence we have ignored other 

 factors that nre ^ven greater importance than those we are considering.- 

 Just what the factors are that have played havoc with our conclusions, I 

 will not attempt to state. I have no doubt that some of them are entirely 

 unknown. I will venture to say, however, that they are mainly physical, 

 chemical and bacteriological; that if we knew all that might be known 

 concerning the physical, chemical and bacteriological conditions of the soil 



