95 
SECTION ON AGRICULTURE AND CHEMISTRY. 
The first meeting of this section was called to order at 2 o'clock p. in., November 
17, in the banquet hall of the Shoreham, by the chairman, ('. <>. Hopkins, of Illi- 
nois, at whose request B. W. Kilgore, of North Carolina, took the chair pro tempore. 
C. G. Hopkins, of Illinois, read the following paper: 
The Present Status of Soil Investigate 
The permanent maintenance of the productive capacity of the soil is a subject 
which'transcends all other sul ejects in its importance to American agriculture, if not, 
indeed, in its importance to the American people. 
Does not the ultimate position or final destiny of America rest upon the question 
whether the crop-producing power of our soils shall continue gradually to be reduced 
or whether it shall be increased, or at least maintained? We need not ask whether 
the fertility of the soil can be absolutely and completely exhausted. The funda- 
mental question is. Will the system of farming which we practice or advise ultimately 
reduce the productive capacity of the soil? 
Because of the present very general interest in soils and soil investigations, it seems 
especially appropriate to discuss this general subject at the present time. Surely 
there is no subject pertaining to agricultural science and practice regarding which 
there is such a diversity of opinion as the subject of soil improvement for increased 
crop production. Both practical farmers and even eminent scientific authorities dis- 
agree almost absolutely on some fundamental principles. Indeed, these differences 
of opinion are so marked and so frequent that I feel compelled to ask, in language 
which has recently been declared to be grammatical, " Where are we at?" To illus- 
trate: 
There is a large class of fruit farmers who practice and advocate clean cultivation 
of orchard soils, sometimes with a cover crop during the latter part of the season; 
while another class of successful fruit growers maintain and strongly advocate a con- 
tinuous grass cover kept under suitable control. Some of the important details of 
this practice are included in what is sometimes called the ''Hitching system" of 
orchard cultivation. So tar as can be learned, the advocates of each system are 
equally positive that their practice is vastly superior to the other. It is extremely 
doubtful if an absolutely fair and complete test has been made of the comparative 
value of the two methods. It seems difficult, for example, for the advocates of clean 
cultivation to understand that a permanent grass cover can mean anything else but 
an ordinary hay field or an unrestrained growth of grass and weeds. 
Again, there are about 75,000,000 pounds of nitrogen resting upon every acre of the 
earth's surface, and the investigations of several American experiment stations, espe- 
cially those of Delaware, Illinois, and Canada, have furnished abundant evidence 
that under proper conditions nitrogen can be obtained from the atmosphere for the 
use of farm crops at a cost of about 1 cent a pound. On the other hand, several 
other experiment stations, as New Jersey and Ohio, advocate the purchase, to a 
greater or less extent, of commercial nitrogen, at a cost of 15 cents a pound, for use on 
ordinary farm crops, such as corn, oats, wheat, or timothy. 
Dr. Bernard Dyer, one of the eminent English authorities on scientific agriculture, 
even advocates the purchase and use of sodium nitrate for growing leguminous crops, 
especially for alfalfa. & From our own investigations in Illinois we have conclusive 
proof that at 15 cents a pound we have obtained at least (45 worth of nitrogen from 
the atmosphere per acre per annum by means of alfalfa properly infected with the 
alfalfa bacteria and provided with suitable soil conditions, free from acidity and well 
supplied with the mineral elements of plant food, and the evidence strongly indi- 
cates that even much more nitrogen than that was obtained from the air.-' Dyer 
does not state, bo far as I can learn, whether his alfalfa was well infected with the 
proper bacteria. If not, of course the application of sodium nitrate would be expected 
to produce a marked effect. 
Bee also Illinois Sta. Ciiv. 72. 
^Reprint from Trans. Highland and Agr. - - otland, 5. Ber., 14 (1902): also 
Reprint from Jour. Roy. Hort. Boa, 27 19Q2 . No, 4. 
<-' Illinois Sta. Bui. 76". 
