194 



DRY FARMING CONGRESS. 



CLIMATIC AND SOIL MOISTURE CONDITIONS IN THE GREAT 



PLAINS AREA. 



(Dr. L. J. Briggs, Washington, D. C.) 



Ladies and Gentlemen: I shall break my talk tonight into two por- 

 tions, one of which will outline to you briefly the ideas which we are 

 trying to get at in connection with the investigation of the physical 

 conditions of soil and climate in connection with crop production; the 

 other will give you some of the. results which we have obtained during the 

 past year in connection with experimental farms being conducted under 

 Prof. Chilcott's direction, in co-operation with the State Experiment Sta- 

 tion in the Great Plains Area. 



The Great Plains Area may be defined as that region lying on the 

 east side of the Rocky Mountains below the 5,000-foot contour and ex- 

 tending eastward to the ninety-eighth meridian. This is essentially a re- 

 gion of -dry farming. But as you have already seen, from discussions 

 that have taken place during this Congress, it is a system of dry farm.- 

 ing entirely different from the conditions here in Utah. It is essentiall}^ 

 a region of summer rainfall instead of winter rainfall which you have 

 here. Professor Chilcott has already outlined the work on crop rotation 

 and cultivation methods which is being conducted under his direction in 

 this area by the Department of Agriculture in co-operation vnth the Ex- 

 periment Stations of the several states lying within this area. 



The study of crop yields in relation to different systems of tillage 

 does not alone furnish the information necessary to enable us to make 

 substantial advances in dry farming. We must know in addition the exact 

 conditions under which a given crop is produced. We must also know 

 the yield of the other crops of the same grain produced under other 

 known conditions. By comparing the yields and the conditions under 

 which the different crops were produced, we can in some cases determine 

 the factor or factors which were instrumental in giving a good yield or a 

 poor yield of grain in any particular case. 



Let us suppose now that we have found one factor which is largely 

 instrumental in determining the yield of the crop. This factor may or 

 may not be under our control. Let us assume that it is a controllable 

 factor. To take a concrete case, suppose the humus content of the soil 

 is the factor under consideration. If the humus content of the soil in a 

 particular instance is sufficient to give maximum yields, we endeavor 

 simply to maintain that favorable condition. If in another instance the 

 humus content is so low as to give poor yields, we try to remedy the diffi- 

 culty by the use of soiling crops, and so increase the humus content of 

 the soil to the required amount. This illustrates the method of procedure 

 with controllable factors. The main point however must again be em- 

 phasized. Working in this way we are no longer groping blindly in the 



