RECLAIMING LOST NITROGEN. 155 



been extremely irregular, just as would be expected in con- 

 sideration of the facts given. Some experimenters have found 

 no advantage accruing from the use of the material, no larger 

 crops being produced, and no larger fixation of nitrogen in the 

 soil which was inoculated with the culture, than in the soil not 

 thus inoculated. On the other hand, quite a number of the 

 experimenters have reported a very striking difference in two 

 such series of experiments, and have found that the inocu- 

 lation of Nitragin into the soil has increased the yield and 

 produced a larger fixation of nitrogen. Without attempting to 

 discuss these irregularities in detail it is sufficient for our pur- 

 pose to present the general results of experience with Nitragin 

 by the following summary : 



Where it is desired to increase the nitrogen compounds in a 

 sandy soil, which is very poor in nitrogen and does not sup- 

 port legumes properly, the use of Nitragin frequently results 

 in a very greatly increased yield. In a single test with clover, 

 inoculated soil yielded 143.7 ^ s - f nitrogen, while a similar 

 uninoculated soil yielded only 4.3 Ibs. The reason for this is, 

 evidently, that in such sandy soil the tubercle bacteria are not 

 present in sufficient quantities to make possible a luxurious 

 crop of legumes. Under these circumstances Nitragin fur- 

 nishes the needed bacteria, and its use far more than pays for 

 itself in the increased yield and in the considerable gain of 

 nitrogen in the soil. On the other hand, in moist soils, in those 

 that contain more nitrogen, and in soils where legumes have 

 grown well in recent years, the use of Xitragin seems to result 

 in no advantage. These soils are already stocked with proper 

 bacteria and the addition of those in the Nitragin produces no 

 advantage whatsoever in an increased yield. We must look 

 upon Nitragin, therefore, as a material which is of distinct 

 advantage in the raising of legumes and fixation of nitrogen 

 under some conditions, especially in barren soils which do not 

 readily support leguminous plants. But it is not a material 



