REPORT OF THE SECRETARY. 27 



increased one-third every ten years until 1880, and afterwards 

 one-fourth to one-fifth. Our expanding farm area has easily pro- 

 vided sustenance for our increasing numbers. But with the filling 

 up of our unoccupied spaces some have begun to fear that in the 

 near future we shall be unable to provide all our food from our own 

 fields. Population increases; yields decrease (so it is said), and the 

 time is at hand when we shall have to import foodstuffs; our eco- 

 nomic independence will then be gone. 



Immigration, liowever, is not to be counted upon permanently to 

 furnish an}^ considerable annual increase in our numbers. Three- 

 fourths of a million may enter our ports in one year; but the very 

 next year may see a financial depression, with the tide of emigration 

 setting away from our shores. Only the birth rate ma}^ be counted 

 upon as a permanent force acting toward increasing the population; 

 and the increase of the native-born population by excess of birtlis 

 over deaths in this country is only about 1| per cent a year, with a 

 tendency toward a decreasing birth rate. 



The great question, then, is this: Are the products of our agri- 

 cultural lands increasing or decreasing in quantity? Is the yield 

 per acre of our fields keeping pace •with this normal increase of popu- 

 lation by births ? To the latter question the answer is that the 

 process has begun. 



RISING YIELDS PER ACRE. 



Dividing the period from 1866 to 1909 into four decades and a 

 succeeding short period of four years, the yield per acre of corn is 

 shown by a study made in the Bureau of Statistics to have declined 

 2.3 per cent from the first decade to the second, declined 8.2 per 

 cent from the second to the third, increased 7.7 per cent from the 

 third to the fourth, and increased 7.1 per cent from the fourth decade 

 to the succeeding four-year period. 



For wheat an even better showing is made, since the figures show 

 a continuous increase in yield per acre, namely, 3.4 per cent from 

 first decade to second, 3.3 from second to third, 6.3 from third to 

 fourth, and 9.6 from fourth decade to final four-year period. 



For cotton, the first figure,. 2.8, is a decline, but the rest are in- 

 creases, namely, 2.6, 3.8, and 0.3. 



For tobacco, the first figure, 3.4, is an increase, the second, 2.0, 

 is a decline, the third, 5.2, is an increase, and so also is the last, 9.7. 



Similar facts are shown for six other leading crops, namely, oats, 

 barley, rye, buckwheat, hay, and potatoes. Not one of the ten 

 crops named declined in yield per acre from the tliird decade to the 

 fourth, while oats was the only one to show a decline from the fourth 

 decade to the last period of four years. The evidence is very plain 

 that the yields per acre of our crops are now increasing, and if the 



