Hi 
A LAVOUHA Mar<;o-Ahril — 19»2l 
(hull's ( I <• humus nceessiii'lns n limn him con- 
illciin ilc eslruurn hum solus tropiriiis mio j ><■ 
q u fit ns, into chegiiudo it rigor 11 suprlr iim cxi 
geiifins no lorn nlc n esse linportniiU* flcmcnln 
ill* niuiiiili'iivdo <his boas i'oikIk'i'i'm finlrnx c 
I ii in lx'* in Idnlogicux ilo solo. Apexnr c it I ret unto 
ili'ssii pi*i| i ii* ii ii porcciilngrm, min pmlr mit cun 
siili'l'nihi roinii inulil tin piMilo ilc visln tin n. 
flni'iiciii (pic puilc Icr sAhre u proeesso ilc evo 
luviiu ipic InlrliiHcciiincnl'' i-oinprccnilc n dc 
roiiservncdo. 
Nil opcrucdo iln 1 1 nc 1 1 n in I ii. | iii > prnlicniln 
Infclixmcntc no llrnsll, silo dcstriiidus quniili- 
dniles vnornii's ilc Iiiiiiiiim nlcin ilc oulron dc. 
incnliiM <|c niiliirczn iniiicrnl ipic siio cm pnrlc 
void I i I i ziiiIiim pclo cnlnr ilcscii volviiln iluriintc 
n cuinliiiMtiin, nncsnr ilc ilixcrcm os ipic n prn- 
llrnm epic o solo ficn cnriqiiccidn coin ns cln. 
/.iim ipic siio dcixiiiliis coiiio ri'sliiun. Till urgii- 
mcnlo min podc scr nccllu coiiio jusldicnlivn 
tin ul i I iilnilc iln ipieiniiidu, servindo >piiiiidn 
in nito piirn explicur n sun nrccssidniic por 
transportin' us rcsidiios ipic ficiini ilcpois iln 
ilci'i'iihiidii coiiio ili/cin iniiitus lnvnidorcs. 
Ali'in ilissu n pnrccntagrm dc cin/.ns c pcipicnn 
cum rclnciiu ii nins.su vcrilc qucimndii, puis mio 
vii i cm genii ucimn ilc f.'i. (I ipic ficn dc suits 
I ii lie ins ii it I r i t i vii s nns cin/.ns mio purccc cum. 
pen sue ii perdu do humus sofridu, nlcin dns 
Vnntngeii.x epic podcriniu ndvir piirn ns condi- 
(' ics gernis du solo pcln presenyn iln Iiiiiuiin. 
A I iii s min c fiicil convcnccr u inuilos dc 
ipic ii ipicimndii e prejiul icinl no solo, puis lui 
ns ipic upclain pnrn du coino linicu recurso 
piirn n climinufiiu dc grundc.s (piuntidudcs dc 
icsiduiis vegetnix ipic ficnni depuis du derm. 
Imdii. Afii-inum muilos (pic e nuiis ccondinieo 
ipiciinur du (pic Irnnsporlsr pnrn ccrlos pon- 
tOS du fn/endn esses rcsidlins. 
A mnlrrin orgilnien, I tin preciusu coiiio 
Siilx'inos, pnni ii vilnlidndc du solo mio c ilcslc 
Hindu iiproveitiidii. Sc n mullvo ilcssu pi ilicu 
c u dc nrdem ccomiinicii, pc In impussiliilidadc 
ii I i*Mn i In dc rcilivcr Indus ns rcsidlins, mio ficn 
fiicil dc ciiniprccndcr puripic inolivo mio sc 
nprovcilu no menus nlguu.x deles pnrn n olden- 
(•iln dc "rnmpnstn”, nil'll) dc sc dcxtrilir il quit 
sc iotulidiidi' dc humus exislcnlc im cummin 
supcrficiul du solo, Acrcdilnin nigunx que os 
rcsullmlos dcssn pridien sejnm prcjodicinls 
Inmlii'iii puripic ns snis dc liollissin c sddin pic 
fleam mis cin/us silo iilcnlinns, pudendo con 
forme n ensn produ/ir ccrtns eondiciies dcs. 
fnvoriivcis siihrc ns prupriedndcs fisiens do 
solo ipic sc nchmn soli u forum granular quo 
coino snbemos (• u niclhnr pnrn uxsegumr Jtoiis 
cniidic ics fisiens. Nns driminlnuilus "solus 
enn^udus" dc que lemns grundes Arens nos 
Fstiidns ilc Klin I'aulo, Kin dc Jnneiru c Minns 
(iernis, n midcriu orgilnien c impurlnnlissiimi 
c Inlvi's ii ii n i e n qii'' podc gnrantlr umn mclliur 
condiedo no que di/ rcspcilu u csluhilidudc 
dc cslriilurn, pnrn que pnxsivelmrnlc possum 
nod stir no pcrlgn dc Icrrivcl fliinclu du crosiio, 
A vunliiMCIll que tern o lui inns c n dc scr 
pnllvnlciilc pois c ii in ngente cimciiluntc, 
uiliiidu cuiiiu uKlnmcrnnlc dc ccrlns purliculns 
nns solus iircnnsns, cmpiniilu podc scr dc ncim 
qiiusc cimlriiriii nns solus argilusns, que po- 
deni udipilrir, pcln presenvn dc umn qiuinti- 
ilnilc con vcniciilc dc luimiis, minor pcrnicu 
liilidndc 
Sc n humus Iciii luis nropricdiidcs fisiens 
pndc-sc ciil iii i pergunlnr; Sern verdude que os 
fnlorcs fisiens silo Iim iinportnnlrs mio so j»or® 
o rcndimcnlo dns colhcitns coiiio pnrn ii con* 
scrviiviln do solo? fi cslu umn perguiiln uu* 
pollen dificil ilc responder, principnliiiciilc in' 
ievurmns cm coni n n cxislcncin dc duns csc<>' 
Ins qiiusc antngAnlcii.x, ufirmiitldn umn dclu* 
que ii riquc/ti do solo cm principios nutritives 
c u principnl condi (do pnrn inn hum rcmil" I 
men lo, cmpinnln que u niitru pur sun vci nflr- 
mu scr ncresxdrio Inmhrm uni ccrlo coiijunti* 
dc prupriedndcs fisiens que dcpcndcm dn cs* > 
trill ii ni du solo c que condiciomun cssn prodio 
tividude. Kssn cslruturii, dc que depende u os- 
tuhiliiliiilc c sem ii quid its out not mm icriin cih 
que sc npuiar, nos solos dc clinins tropJeni** 
depende cm primeiro liignr do humus c ci" 
scgiiiidn lunar du cnlcio. Isso pnrqilc uni solo 
c cuiisidcriido dc Imu cslrutilra qiiundo cull- I 
lem qiinnlidndcs rcgulnrcs ilc cdlcio cm coll- 
dipdes dc saturnr pcrfcllnmcnlc u humus que 
ill sc cncoitlrc pnrn old liter iis linns condign*'* 
dc gruniiliivun c pur conxcquAnc in n inlcgri* 
dude dns prupriedndcs fisiens. 
A presenen dc cnlcio A tiimhcm dc lino' 
importuncin pois c die om niilrimciitu :ilcm 
dc scr iiiii uiixilinr iiidispcnsdvcl iln ponto dc 
visln fisicn. Ilii alid.s umn cxpcriv'nciu simple' 
que puilc scr feita coin out solo argiloso que 
ciiiilciihn percentage))) iiprcciiivcl dc Itnmiis: 
npns u hiimedccimcntn com iigun c sccaRCtn 
ficn dc iliiro c impcm-travcl ;depnis dc hu- 
iticdcciiiicnlo com iigmi dc cal c secagem sub* 
scipicnlc, ficn fiicil dc scr cshnruailo, c qoe 
dcinonslrn clurnmcntc n iiifliiciicin iln cn) coin** 
tigciilc dc floculacdo, quer discr que pcriuife 
que us purliculns dc arpiln c dc humus ci" 
csiiuln dc extreinn subdivisiin possam scr ,'iRlo- 
nicrndns c dcssc modn Mrnniiliidus. 
A fiilln dc innlcria orniniicu iio solo c 
caiisiidoru dc sitiincnes its vexes caliistriificH' 
cm iiIkiiiiius regimes du nlulio, inormente na- 
(ptcliis sujcitns a chiiviis rcgnlnres pnrem inoi- 
In nfnsliidns limns dns uolrns pur Iuiikhs cS« 
lindens. Fni u (pie neonteceu lui mdses dc emu 
nnns nriis cm vnsltis Arcus dc solus mi pnrlc 
nuruesle iln Amcricn du Norte unde ;i prcci- 
pilufim iinuni ulingc ecren dc .iiil) milimctroi' 
por aim. Os primeiros agricultures que ni ue 
cslnhclcccrani viram que ern umn rcgiiiu lnuit® 
cimvcnientc pnrn n pluislio dc Irigo e dcscif 
vnlvcrnm mu sistemn no quid dssc cultivo nl- 
temava com n ulqocivc. Nadu fid feilo col re* 
tnnlo pin u rcstituir no solo a mnlcrin orgdiiin* 
c o const :i ii I c cultivo rcduzill dc lui inoilo <* 
sen coiiicudo iiu solo (pic cslc f icon cndii vc* 
mnis pul vcriilcnln pcln aiisdncin ilc quiilqucC 
agente cimciilniitc c finnlincnlc tilo f i no que 
poude scr Icvado pclo vento pnrn Hindu longe> . 
(iriinilcs Icinpcsladcs ilc pneira lcvunturiioi.se 
freque iilcnicutc c Icvarnm grunilcs qiiniitiiln 
dcs dn enmada superficial dc solos ilc milliAc* 
dc ucres dcixnndo npcnas limn im siifiirn c dc 
setien no Incul unde outrnra luiviam cxistido 
fnxcndns prdsperas c solus fcrlcis. A mnlcrin 
orgiliiicu di've scr fnrnecidu por umn couslnnlc 
cuhcrturii ilc vcgcluvdo, c prefer! vclmcnlc fa 
Zendo n rnlnciin dns clllllll'US, 
A crusiin sAiuciilc Inrun sc ncrigosn quon- 
du n culicrlurii vcgcliil c complclumcntc nit 
radn, ficuudo •> snlu dcsculicrtn duriinlc inuito 
tempo, outs idem ilc fienr sujcitn ii iu.nu nuiis 
ilireln dns chuvas piulc Icr grundc pnrlc iln 
mnlcrin nrgdiiicu que cnccrru coino cslnhili/n 
dor dcslriiidn pcln nciiu ilireln dos nil us suln- 
