io8 



Journal of Agricultural Research 



Vol. XVI, No. 4 



lating influence of various substance upon bacterial activity and the 

 manner in which the stimulation is exerted. The results thus obtained 

 can be directly compared with those obtained for higher plants. Then, 

 if a correlation between the two, the lower and the higher plants, be 

 obtained, it should give a quick method of testing not only alkali soils 

 but also other soils containing various soluble constituents. Further- 

 more, it makes possible the studying of balanced solutions within the 

 soil by means of bacteriological tests, thus getting in a short time com- 

 parative results which with higher plants would be obtained only by an 

 enormous amount of work and time. Knowledge thus obtained can be 

 used in the reclaiming of the alkali lands of the arid West. A careful 

 review of the literature has been made elsewhere and, hence, is not in- 

 cluded here {3)} 



EXPERIMENTAL WORK 



The soil used in this work, taken from the College farm, is of a sedi- 

 mentary nature. It was deposited by streams flowing into the valley, 

 laden with debris derived from the near-by mountains, which are com- 

 posed largely of quartzite and limestone. A physical and chemical 

 analysis of the soil is given in Table I. 



Table I. — Physical and chemical composition 0/ soil 



The soil used, therefore, was a sandy loam very high in acid-soluble 

 constituents, but the water-soluble constituents were not excessive. 

 The calcium and magnesium contents were very high and mainly in the 

 form of the carbonate. The soil was well supphed with phosphorus and 

 potassium, and there was a fairly large quantity of iron present. In 

 fact, all of the elements of plant food were present in abundance, with 

 the exception of nitrogen, which was low. The soil was very productive, 

 and previous work had shown the ammonifying and nitrifying powers 

 of the soil to be about the average for the soils of the arid regions. The 



' Reference is made by number (italic) to " Literature cited, " pp. 134-135. 



