140 lines
3.8 KiB
Plaintext
140 lines
3.8 KiB
Plaintext
- Sand eunreru,
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. General lerrure.
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. anwess
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. Strucluxe (on, soils).
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. Wee—season Il'rumln
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- Vegeiauvernduammreelrn" ofa speeru rrvpl.
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. Drainage.
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. slepe
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- Elevauon
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- Animal lndlcabols (e g. rernurea inesnape and sine
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of mere moundsl
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. naminumum iloraeiuily, drill-n52, fatality)
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- Cakeni llypes o! sox|s based on slope
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relanurrslupsl,
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. “Hm” Ind ~eolu~ w — remive (utility lnrr
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mperarurel, can also mime waler menuon
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- Usage, 2.3 pigmenrs, punery, salr amnion [mm
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reeds,
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. work neeueu tor erop ian ”logy l'nyul
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d-siiiumn)
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- Surlabrlrry lor speerire (mp (e g yam soil, raro
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sorll smls an be rankzd (or up b, rwelve mp typo,
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giving a eomplex elaesilieaupn
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- Olga-"c conlenl lapan lnnrr culmm
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Thus, sophlslmaled assessmenls ol sorls are availabk
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[mm mosl agricultural sporerres. However, modern
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elarsilicauuns are more cumplex in lerms oi
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numenelalure and pnysreal earegorres, and use
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srauuaru eoluur ennns iMunsell nnd 0mm), slur-dud
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mmpnrisons, sundald sieves and so on
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8.4
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THE STRUCTURE OF SOILS
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Soil is a eompler marerral, and il il has Enough
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plesuciry lusually rlay), or glue or fibre lion. mamr
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ruurees, n ran be pressed or eompasred lnle
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mudbntk's. hard prss. arbalvtd |o elay or smnewure. ln
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any ohhneiurms, msuflillleuutophnb
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Ullwlllplded soils are open, crumbly, or soft unless
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eonrreled by enemreal solules be eompaered by
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ploughs, homes, or lullic. crumbly soil! hm
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nevennelees . definite smutuw no soil pawns are
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m nodules or elumpe held together by room, elay
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minerals, and (hmlnl bands. If we speed a plmugh or
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flag harmws |hm5h llnese lmgfle iskmblin, msy
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may powdu up u my do in a party's ballmrll, UK on
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uulbazk roads. 1"Bulldusl” is are men used in me
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Ausnallan eulbaelr. A soil selenusl mrprl spuk pl
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~snull~l Dlyland Sm!) wirlr a lugh uh cunlenl are
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pzrfindally suseopobls In [Out ol crumb mum-s, only
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p-nly relieved by apphalion ul gypsum.
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m maulleolsorl and snbsml llrarmwerelbe uardl is
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as min as IM shine on me skin M an cringe, and nus
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manrle exlends as livlng mud below me warers ul
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earlh as well as on land It is composed ul mese
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elemenls.
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136
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. MINERALS, mlxmly silica, ruruies oi )mn ind
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aluminium and Lvmpkx minerals.
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. soil. warms, lreslr, saline, Will.
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uld flinch/ed minerals and gut-
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- GASES, some leum ale almospbere, olhm ermned
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by llre I’m-known bl roelss and llre eaerlr's rubeuor
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. m1: FORMS, irom rurrgal spores and baeieria u,
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wumbars and 51mm! squimlx, lrrnrr mm rools Io
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rrunule meme algee.
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r oNCFruVmc REMAINS, rm lrumus el me earrb;
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decay/est camp-eased, and leesu alganic mabenal.
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Soils rarely menu much below 1—2 in, end are more
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oleeu a luring syalem H2 em deep. Subaoils, lacking
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use lue componen-s, and buried nails or Mp washed
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rins are rare sud momma lb valley floors and dell», or
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glaml mmmus.
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1p esrlrnare lne propomeu a! elay. 91114 mud, and
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coarse panda in soil, a sulfierenl um lesl liar iudgns
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me willbflily ol soll lor dam building, mud belelr
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cnmtmnian, and emp types), flux a sample ol soil
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irem . lew Iyplul ailes, and pour a eup ol soil in a all
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gar, and almost wlrlu waler, slulre vrgomsly and lei
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lire soil incubus senle our over a day or a weelr (clay
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on mlum In nrspension fur up lo a ween. m or so
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thy ls needed lor dam walls, and less man llul lor
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good mud bricks (wlthont lime or eemenl addedl.
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or rhese lraeuons, the muse parueler are men,
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:lkhuugh uselul In line sorls as a wind>emslon
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damn! Suds are ms: mm. sill n os-om mm. elay
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pumdes less man mm mm ll g 0! elay has a surlaee
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Imohlplo mmlimtslhztoll gulsanal,
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Sol] erumb souolure, alded by lime iealuuml axds
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me bonurn, wsethrr ul llrese lrsmions and males
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20-60% poR rpaee Tire ergs malerrals and gels
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hold me srruerure open in rain, and where planl
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numenrs can beepme soluble {or ibwrplwn by ruers
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' exlng pl-l,
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50H. Fauczsses.
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m use» Mullen ul soil mm Irv lumrs Vu
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