Ill, — ^THE RISE OF SCIENCE IN AGRICULTURE 



seed grain are always liable to be contaminated with the seed of weeds. 

 It is our desire to establish standards of purity and of germinating power 

 for all the chief American seeds, and in this way promote the trade in 

 these seeds and especially the demand for them abroad. Our exports of 

 clover seed are already very considerable, and many seeds of commerce 

 demand the oversight of this Department. 



I speak this morning to many agricultural chemists, so that I need 

 not take time to explain the disappointments that we have all felt with 

 regard to the results of the chemical analyses of soils. We must acknowl- 

 edge now that we can not tell the practical farmer all that he wants to 

 know by a single analysis of his soil; that it often requires many analyses 

 to learn, even approximately, the chemical nature of the soil of a given 

 section and that, even when we have made these, we are unable to ex- 

 plain why one soil is productive while another fails entirely. We all 

 know cases where soils having almost identically the same chemical com- 

 position yet differ greatly in the uses to which they can be put. In short, 

 the chemical analysis of the soil does not tell us the w hole story. A great 

 deal more is to be learned about it before we can tell the farmer how to 

 make it productive or why he should put one particular crop upon it 

 and not another. Our Department has decided, therefore, to attack this 

 old problem from two different sides; first, from the physical side, by 

 studying its relation to heat, moisture, etc.; and second, from the bio- 

 logical side, by studying its nitrifying organisms, etc. This we hope to 

 do without neglecting the old lines of chemical investigation. 



A new division has been created in the Department to be known as 

 the "Division of Agricultural Soils," whose duty it will be to study the 

 rainfall and temperature after they have entered the soil and to keep a 

 continuous record of them in the most important types of soil in our 

 country. Our Weather Bureau keeps a record of the temperature and 

 of the moisture in the air and of the rainfall until it reaches the surface 

 of the soil. It is proposed in this new division to continue the study of 

 the rainfall after it enters the soil. The actual conditions of air, moisture, 

 and temperature which soils are able to maintain largely determine what 

 classes of plants are adapted to them. These things depend in turn upon 

 the texture of the soil. Even with the same rainfall and exposure to heat 

 it is well known that different soils maintain very different conditions. 

 This difference in the meteorological conditions under the surface has 

 an important bearing upon the adaptability of soils to crops, because of 

 the influence on their development, yield, texture, quality, vitality, and 

 time of ripening. 



Soils adapted to early truck and small fruits, for example, are sandy, 

 open, and warm, allowing the rain to pass through them very readily 

 and maintaining only a small amount of moisture. This dry condition 

 gives them their peculiar value for forcing vegetation to an early ma- 

 turity. The tobacco soils of Pennsylvania owe their peculiar value to 

 their close texture and to the fact that they maintain an abundance of 

 moisture for the crop. This produces a large, heavy type of wrapper 

 which competes with the Cuban tobacco. The tobacco of the Connecti- 

 cut Valley, on the other hand, is grown on a very light textured, sandy 



[39] 



