38 



Journal of Agricultural Research 



Vol. XVI, No. 2 



Figure 2 gives soil nitrates, aerobic, and anaerobic bacterial numbers 

 for the series of soils where moisture was the variable. These graphs 

 shows that lack of aeration which changed the proportions of aerobes to 

 anaerobes prevented a correlation between nitrates and aerobic counts. 



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y£^^. cy^y u^///r£- ^/zr 



s-zpcuffw zo^/^ /5zyf«r/r^.s>'j/vz> /3/PC^A^ ^^^s^r 



FiG. 2. — Graphs showing the relation of aerobes and anaerobes to nitrates in five acid soils kept at 



different moisture contents. 



GENERAL DISCUSSION 



After conducting bacteriological investigations on acid soils to ascer- 

 tain "if it might be desirable to consider more carefully the possibilities 

 of a system of acid agriculture," Bear (j) concluded that — 



the supply of nitrogen in acid soils may be maintained by growing acid-resistant 

 legumes, of which the soy bean is one. Undoubtedly the use of acid phosphate aids 



