468 IOWA DEPARTMENT OF AGRICULTURE. 



SUMMARY OF RKSULTS OF EXPERIMENTS. 



In the spring of 1903 twenty-three experimental plots were established in 

 as many different counties of the State. The soil ranged from heavy clay to 

 light sandy loam. In each case the alfalfa was sown with and without a 

 nurse crop. The nurse crops consisted of light seedings of oats or barley. 

 Each plot occupied one quarter of an acre and all were inoculated with soi^ 

 from old alfalfa fields which contained the alfalfa bacteria. The soil was 

 applied broadcast at the rate of one hundred pounds of dry soil per acre. 

 The alfalfa seed was sown at the rate of twenty pounds per acre. 

 The seeding was done at diflferent times, the dates ranging from April 10th 

 to June 15th. Of eighteen satisfactory reports secured in the following 

 autumn, eleven showed good condition, six fair and one rather poor condi- 

 tion. Seven reported best stand without a nurse crop, four with a nurse 

 crop and six reported no difference. Of those reporting fair condition, five 

 reported damage done by dry weather shortly after the crop came up. Of 

 those reporting ^(30^ condition, seven reported nodules on the roots, one 

 none, and three did not examine the roots. Of the second group, four re- 

 ported some nodules, two found no nodules and one was doubtful. The one 

 reporting poor condition found no nodules on the roots. 



In the spring of 1904 nine additional plots were established in other sec- 

 tions. The general plan of the experiments was the same as in 1903, except 

 that only one-half of each plot was inoculated, and in such a way that each 

 plot was virtually divided into quarters, one having alfalfa, nurse crop and 

 bacteria, another alfalfa and nurse crop, another alfalfa and bacteria and 

 the fourth only alfalfa. The object of this plan was to determine not only 

 the advisability of using a nurse crop but also the necessity of inoculation 



