125- 



The bulk of bacterial action tnkes place In the upper 12 M of 

 gs or agricultural lands; in forer.ta it goes i little deeper. Bacteri 

 ye abound, in lr..r^e numbers, ?Sien present; the greatest number per 

 centU.fcter in rich clay was 600 million b^cterir; tne upper inch usually 

 contains ..loct. The abundance of bacteria varmes widely, even in adjacent 

 localities, <~nd yields from soili? vnry in rbout the r ,-roportion. 



-production of "bacteria is v,rry rapid: cell civision may be com- 

 -,lcteu i/; _>0 minut J, .,.-;; id produce JO generations in 24 hour 

 if en.rriet-. on continual!./. t nu of the c:a^f values of stable manure is 

 the fact uitf ret bacteria life in the soil (Hilgard 



, t\vo i 3 Vrctc: 



i; - : f organic 'ial i/ l.^oth r>riimn.l and plant. 



2} Secretions act on inorgnnic minerils both physically and 



cherr.icnl the nitro^n -up^ly in soil. 



ct^ria Biay ije Divided irjtu .-jccirairi^ to the work they dfl 



i;. . n cellalcsc, chiefly by fermentation. 



2/ :;ccc;.'-;^se protein bcdi action occur?, in all soils, 



.tter of .11 3ci. v j 



litrifying bacteria; a very ccir^ion forto. I need lots of 

 nir to c ' an thei] " , require a tercpi - of over ^0 I 



Tiie soil be cither neutral or alkaline. ?hn Dacteria prefer soil 



v?ith ;'lGntj' oi 1 li::'o and organic food. They use tl:a free nitrogen of the 



i i r . 



4, ; t-, : rclci bactcrJ.".: take free- nitroc n ^r-o "bJnf^ it; they ao 

 title, o;,i j Abiotic rel-.UioriS. Th^y an figl myC< ' ;*, as some people 

 have Tnifi; ht. They ar fo 1 .iefly on the Leguminoaft*, arid 



. .-/Jhe tuborcl 13 ' .i:', :; they then cease, be- 

 .- - -- , nd are absorbed, 



.rily . (.cteria take nitroen fr --oil, and are very 



Ly do not do very ruuol: uar^cr, ae they ar-.- not plentiful, anc 

 en only under certain conditions. 



Other groups -^e aul^liur bacteria, iron bacteria, etc. 



,-roJC3 of bnc. the isoil; tliey occur by tone, ever actii 



ready to do a variety of thiri^a vith or^.nic tilings. They accom- 

 pli I" ; idou-3 'u'.iuunt of " 



. 



b. 



These fungi s.rc more common in fcrer,t or uutilled so^l than 

 in the fan&ei' f a tillaa law - -- - ^'^Ipa to vlimBte tha, 7hcir chief 

 valu^ lies in the di-c. ->n of iiQ natter; Die formation of 

 us is largely due to fuiifci . They penwtrate theu the soil ami distri- 



ir fil ^feBi-y evenly thru tl il, h to feea other 



fun ,;llo"'intj the ;-cil. 



. mor : ..-; i in the mulch of hrvrdvoud:- Lhnn vith conifen 

 The liT; -ma ^ruv/th of funrji are almilar ^o that of bacteria, bui 

 ore limited. They need or^.nic, ?md arc helpleas v/ith inorganic ma- 

 :v are largea and men ..... 'outli th-^.n are b* 



ria. They ta3 .frjanic mt-rial (and ccimcnt it) only thru a dis- 



tinct 'process, leaving till job for another fungus to '.--ork over in the 

 x t step c f dec o^rp o s i o i o :i . 



gi livv: part of ttieir lift In - 11, and part as parasites 



