THIRTEENTH ANNUAL YEAR BOOK— PART XII 663 



reports. In 1905 and 190'6 its value was "estimated" in combinations with 

 another crop under the head "Millet and Alfalfa." Its growth in im- 

 portance in 1907 and 1908 is indicated only by the change to "Alfalfa 

 and Millet." In 1909 and 1910 its acreage within the state is given as 

 23,041 and 24,132 respectively. 



A few men have been growing it for from ten to thirty years or more, 

 but 80 per cent of those growing the crop in Iowa now have seeded within 

 the last five years, and the majority have put in their seedings within 

 the last two seasons. 



The oldest Iowa seeding of which we have record was made at Bur- 

 lington something over thirty-five years ago by a farmer who brought 

 the seed with him from his home community in Germany where it was 

 called "thousand year clover." It continued to grow and produce seed 

 year after year in its new home, which was a north slope of what our 

 correspondent called "a clay sidehill" of rather low fertility. This is 

 probably a loess soil. The original field is now included within the city 

 limits of Burlington. Much of the original area is devoted to buildings 

 of one sort or another, but where the alfalfa yet has opportunity to grow 

 many plants continue to thrive. A few years ago seed was secured from 

 this plot and is now being grown at the experiment station under com- 

 parison with other alfalfa seeds secured from various sources through- 

 out the United States. The fact that plants from this seed are much 

 more uniform than any other grown on the 55 plats with which we are 

 experimenting, indicates that the natural selection which has been going 

 on during the past 35 years may here have produced a plant of special 

 value to Iowa farmers. 



IOWA SOIl^S AND ALFALFA. 



A little study of figures will give reason for faith in the ability of 

 Iowa soil to grow alfalfa. In 1910, 24,132 acres of alfalfa in Iowa pro- 

 duced 65,629 tons of hay, or an average of 2.7 tons per acre. Most of 

 this acreage was in the counties bordering the Missouri river, though 

 some was reported from all parts of the state. The acreage, total yield 

 and average yield per acre are shown for each county in table VII. The 

 distribution of this average is better shown in fig. 9, in which each dot 

 represents 10 acres or major fraction thereof. 



These facts give some idea of the general adaptation of Iowa soils 

 to alfalfa, yet they do not indicate fully how successfully the crop may 

 be grown on many of the soils of the different counties, or on some 

 soils on practically every farm in the state. 



One of the best indications of the success of any crop in a given 

 locality is the average yield per acre. From this viewpoint the growing 

 of alfalfa is a success in all parts of Iowa, the yields in various counties 

 ranging generally from two to three tons per acre. (Fig. 10.) 



REPORTS FROM PRACTICAL GROWERS. 



A general inquiry instituted early in the summer of 1911, showed 

 forcibly that alfalfa was growing successfully on every soil 9,nd in nearly 

 every county of tb^ itate, 



