Show tf SOIL NEED OF OXYGEN tuason leason Why Decay of Vegetable Matter Mat Mat- ter Depends Upon Air Supply The rho first condition for tho the changing of green groo plant remains into useful manure manure ma ma- nure is an n abundance of ot air says sas Prof Prot Charles L. L Penny of at the Delaware sta eta tion Much of the time benefit of ot tillage must be bo ascribed to the need of at furnishing fur Cur oxygen to the organisms micro f f the soil which in turn use It to ox ox- protein to nitrates Anything whether the nature of the soil its position position po po- po as to drainage or its treatment that prevents the time access of air to decaying de de- de organic matter will retard or orl l prevent this useful process of or oxidation tion and so will leave a n peat like matter matter mat mat- ter useless as food toad for new tion The Tho vegetable remains of ot marshes cover covered ll wholly or partly by bywater bywater bywater water accumulate for tor years cars with litHo littie lit lit- Ho tle decomposition and that little attended at attended tended by the tho escape o of nitrogen rather rath rath- er than by its oxidation to nitrates Land that has standing w water ter for much of the tho time is unfavorable to nitrification as there is not sufficient free tree circulation of at air In such low lowlIng lying l-Ing lands often orten of ot a black color fragments of plants frequently remain for a 1 long Ions time A stiff compact soil retards deca decay for tor a similar similar simi simi- lar reason whereas In a porous well tilled SO soil trag fragments of mf plants disappear die dis appear very rapidly The Tho Boll soU of ot tore for forests ests eats lacks the tho nitrifying ferment and andIs andis andis is almost free reo from nitrates because the bed of at moss and leaves fallen excludes ex ox- the air from the tho deeper layers of at such remains and so prevents dation Thus it is that the tho submerged of at marshes and to a less extent much of ot the vegetation of ot permanently permanently per per- wet lands passes Into a form torm in which It changes very vory little and becomes practically inert matter so far tar as plant nutrition is concerned A saturated wet soil has the further disadvantage not only that no nitrates ar are formed but also that nitrates already already al al- al ready present are rapidly reduced and antI lost |