840 EXPERIMENT STATION EECORD. 



The scientific basis upon wliich tLe best and most ecouomical methods 

 of managing barnyard inanure rest has claimed much attention recently 

 from a number of the most prominent scientific men of the old world. 

 The i)resent and the preceding numbers of the Kecord contain abstracts 

 of reports on this subject by Deherain, Dietzell, Maercker, Wagner, 

 Pfeiffer, and others. A recent number of Die landunrthschaftliclien 

 Yersuchs-Stationen is devoted exclusively to the subject, and French 

 and other foreign agricultural journals are giving much space to it. 

 Kecent effort has been very largely directed to the practical end of 

 simplifying methods of management and preservation, for it is clearly 

 understood that only the fertilizing matter of barnyard manure is in so 

 dilute and bulky a form that only the simplest methods of manipulation 

 can be i)rofitably applied to it. 



The object sought is a very simple and definite one, but the means by 

 which it is to be attained must be developed by scientific investigation 

 of the most complex and comprehensive kind. The changes which 

 manure undergoes, which it induces in the soil, and Avhich deter- 

 mine to a large extent its fertilizing value, are mainly the work of 

 nucroorganisms. A study of these changes therefore re(piires not only 

 most careful work on the part of the chemist, but also i)ainstaking 

 study on the part of the bacteriologist; and since the conclusions 

 reached by these experts must be confirmed by actual tests in the field, 

 the investigation of this subject furnishes an opportunity for profit- 

 able cooperative work by at least three departments of an experiment 

 station. 



Since the direct fertilizing value of manure depends so largely on the 

 nitrogen which it contains, it will be found that the investigators above 

 referred to have given their attention mainly to a study of the avail- 

 ability, changes, and causes and j^revention of loss of this element in 

 manure. 



Probably the most interesting fact brought out is that coarse manure 

 and litter, especially M heat straw, contain an active denitrifying organ- 

 ism. It has been observed that when such material is liberally applied 

 to the soil the available nitrates present are converted into unavailable 

 forms, the application of manure resulting in many cases in a decreased 

 rather than an increased yield of crop. It has been shown, however, 

 that this effect is not likely to be noted unless manure is applied in 

 unusually large amounts. Still, this is a subject of great scientific 

 importance, and demands that in the study of methods of manage- 

 ment of manure the effort should be made to develop systems of 

 preservation which will not only prevent harmful changes in the nitro- 

 gen, but also reduce to a minimum the activity of the denitrifying 

 organisms, which may prove so injurious in the soil. 



