238 



Kansas State Board of Agriculture. 



MANURING FOR ALFALFA. 



There is no crop grown in Kansas that responds more quickly to barn- 

 yard manure than alfalfa, or upon which it is safer to apply manure 

 without danger of its reducing the yield of a crop in a dry season. While 

 manure is beneficial when applied to an old-established stand of alfalfa, 

 it can be applied with the greatest benefit in advance of seeding the crop. 

 Young alfalfa plants require large quantities of plant food for their 

 growth, and unlike the older plants, which are able to secure nitrogen 

 from the air, the young plants must be supplied with nitrogen from the 

 soil until the plant becomes inoculated with nitrogen-fixing bacteria, which 

 does not take place until the plant is several weeks old. Barnyard ma- 

 nure, if applied long enough in advance of seeding to have practically 

 rotted, will supply the young plants with the nitrogen they require and 

 often insures a stand of alfalfa on soils low in fertility upon which al- 

 falfa would otherwise fail. 



It is generally believed that alfalfa will restore the fertility of im- 

 poverished soils if once established upon them. While it is true that 

 alfalfa will do better than most other crops on soils of this character, 

 and will gradually enrich soils of this kind in nitrogen, it is nevertheless 

 true that such soils can not be made very productive until the soil is 

 manured or fertilized. 



In 1910 a series of experiments with manures and fertilizers was 

 started at the Kansas Experiment Station at Manhattan. A number of 

 plats of ground was seeded to alfalfa that season, and have been in 

 alfalfa continuously since that time. The soil upon which the work was 

 started was a very poor one in fact, the field is more or less rolling and 

 the soil was somewhat eroded. Upon these plats manure has been applied 

 annually at the rate of 2% tons to the acre, or a total of 12^ tons of 

 manure applied during the past five years. One of these plats receiving 

 manure received also an annual application of 380 pounds of raw rock 

 phosphate, which cost $2.08 for the quantity applied. Another plat re- 

 ceived 1000 pounds of lime in 1910 and the same quantity in 1914. The 

 third plat received barnyard manure only. Another plat was manured 

 annually at the rate of 5 tons, or has received during the five years a 

 total of 25 tons of manure to the acre. Other plats left as checks were 

 unmanured. In 1911 the alfalfa winterkilled and was reseeded in the 

 spring of 1912. The yield of alfalfa obtained during the past five years 

 is shown in the following table : 



TABLE No. 25. 



Effect of barnyard manure on alfalfa. Manure applied annually, 

 1911-1915. Yield in pounds. 



* First three cuttings only. Data compiled before fourth crop was harvested. 



