El pasi revhu Ndiyo imwe iyo ivhu rinotonga pamusoro pezvimwe zvikamu zvehumwe hukuru. Clay iboka remamineral particles madiki, asingasviki 0,001 mm. Mudhayamita, ivo vanorairwa kubva kudiki kusvika kuhombe muhukuru, kusiyana nemamwe makuru masitadhi senge silt nejecha. Ivhu revhu richange riine silt nejecha, asi ivhu richatonga, muzvikamu zvakasiyana zvichienderana nevhu riri kutaurwa.
Muchikamu chino tichakuudza zvose zvaunoda kuziva pamusoro pevhu revhu, maitiro ayo, kurima nezvimwe zvakawanda.
Chii chinonzi ivhu revhu
Ivhu revhu ivhu rakaumbwa zvakanyanya muzvikamu zvisingasviki 0,002 millimita muhupamhi, zvinonzi ivhu. Kana hutongi hwevhu revhu hwakanyanya kukwirira, dzinonzi ivhu rinorema nekuda kwekuwanda kwazvo.
Nekuda kweizvi, ivhu revhu rinotora nekuchengeta mvura yakawanda, zvichiita kuti ivhu rive risina mvura uye risina kufema zvakanaka. Kana yaoma, mavhinga anoumbwa, izvo zvinoita kuti basa riome, kunyanya mukurima.
Ivhu rakakosha zvikuru pakuorera kwevhu. Vanochengeta mineral salt nekugadzira aggregates ne humus (iyo colloidal chikamu chezvakaora organic matter) uye yakanaka pakuchengeta mvura. Ivhu rinonyanya hunhu ndeye metaclays (swellable clays). Aya marudzi evhu anowanikwa pasi rose. Pakati pemarudzi anorimwa zvikuru pakati pavo mupunga unomira. Zvimwe zvakaita sepanapple nerabha zvakare zvine kugadzirwa kwakanaka.
Ivhu revhu zvinhu
Ivhu rinopa ivhu kusapinda mukati, mvura yakawandisa, uye kuchengetedza kudya kunovaka muviri. Izvi zvinoita kuti mbereko yako iwedzere. Chechipiri, havana mhepo inofefetera zvakanaka uye vane mukana wakaderera kusvika pakati nepakati wekukukurwa.
Iyo physicochemical properties yevhu inoenderana nekuumbwa kwayo kwemaminerari, kunyanya pamhando huru yevhu. Saka, semuenzaniso, iyo allophane inobatsira kune cation exchange capacity, porosity, kuchengetedza mwando uye chimiro. Nekudaro, kaolinite ine yakaderera cation yekuchinjana kugona, yakaderera element retention rate, uye yakajairwa chimiro.
Kusanganisa
Chikamu chakakosha chevhu chinotsanangurwa sevhu kugadzirwa. Izvi zvinoreva chikamu chejecha, silt, uye ivhu muvhu. Chimwe nechimwe chezvinhu izvi chikamu chegranular. Kana zvimedu zvevhu zvinomiririra 25% kusvika 45% yezvikamu zvese zviri muvhu, inogona kunzi ivhu rejecha, ivhu rakaoma kana ivhu rine silt. Kana ivhu richipfuura 45% yehuwandu hwehuwandu, tine ivhu rakanaka.
Porosity, permeability uye kufema
Kusvika padanho rekuti ivhu rinenge richigadzirisa magadzirirwo uye chimiro chevhu, zvinokanganisawo porosity yayo. Pamusana pehupamhi hwavo hudiki, zvimedu zvevhu zvinosiya zviduku zvishoma. Izvi zvinotadzisa kufamba kwemvura nemhepo mumatrix evhu. Mamiriro aya anoita kuti ivhu rizare, zvichiita kuti mvura yepasi imire nekuti kupinza hakuitike.
Kana iyo pores yevhu yakazadzwa nemvura, rhizosphere ine nzara yeokisijeni (okisijeni inobviswa). Mumamiriro ezvinhu aya, zvirimwa zvinorimwa zvakawanda zvinonetsa kukura.
Muhupo hwe humus, ivhu rinoratidza rutivi rwakanaka. Clay-humus complexes inoumbwa uye zvikamu zvakakura. Nekuda kweizvozvo, ma pores akakurawo, achivandudza kupinza uye kufema.
cation exchange capacity
Kana ivhu neorganic zvinhu zvikasachengeta cations, zvinokukurwa nemvura zvichienda kuzasi (leaching), zvichikanganisa kuorera kwevhu. Iyo cation exchange capacity inokonzerwa nekuti zvese humus nevhu muvhu zvine mutero usina kunaka.
Ivhu pH rinokanganisa cation exchange capacity. Zvinoenderana nerudzi rwevhu riri muvhu. Kana kaolin neallophane zviripo, iyo negative charge inoshanduka nepH. Nepo kana reshiyo yevhu rakawedzerwa iri 2: 1, kubhadharisa kunogara kune chero pH.
Migumisiro pane microbiota yevhu revhu
Zvipembenene zvevhu zvakagadzira kunamatira nekuparadzanisa hukama nezvidimbu zvevhu. Pamusoro peiyi, maitiro ekuchinjanisa ion anoitika anotorwa kana kuburitswa nema microorganisms.
Nekuda kwekuderera kwayo kupinza, ivhu rakanakira madhirigi emvura echisikigo kana ekugadzira. Mamwe maaquifers anoumbwa nekuda kwekuvapo kwedhaka revhu pane kumwe kudzika.
Mazhinji ivhu ndeyeboka re phyllosilicates (layered silicates). Kune marudzi akasiyana-siyana zvichienderana nehuwandu hwepepa rinogadzira chimiro chayo. Iyo yakanyanya kuwanda ndeye muscovite, kaolinite, biotite, chlorite, vermiculite, uye montmorillonite. Imwe mhuri ine mwero yakawanda yevhu ndeye quartz oxides. Muzviitiko zvisingawanzoitiki tinowana feldspar, hematite, goethite, calcite, gypsum uye halite. Cristobalite uye amorphous zvinhu zvinowanikwa muvhu re pyroclastic mavambo (volcanic ash).
Nekuda kwechimiro checolloidal chezvikamu zvayo, ivhu rinochengeta huwandu hukuru hwemaminerari. Ivhu rinowanzochengeta simbi (Fe) uye kusvika padiki aluminium (Al). Sezvo ivhu richichengeta mvura yakawanda, an oxidation process inoitika. Hydrated iron oxides inopa ivhu iri ruvara rweyero kana kuti rutsvuku.
Clay ivhu chimiro
Clay inosanganiswa ne organic matter uye inobatsira kugadzikana kwechimiro chevhu. Kazhinji kazhinji, iyo ivhu-humus yakaoma inokurudzira kuumbwa kwezvibatanidza zvevhu. Ukuwo, sodium inokanganisa ivhu.
Kana iyo substrate ivhu zvachose, haina chimiro uye haibvumiri mvura kupinda. Izvi zvinopedzisira zvaita kuti compaction uye kuoma. Mumwaka wemamiriro ekunze ekupisa kwemwaka, ivhu rine ivhu rakazvimba rinochinja zvikuru maumbirwo zvichienderana nemamiriro akaita mwando.
Munguva yekunaya kwemvura. ivhu rinozvimba uye ivhu rinofashama nyore nyore, richiva rakapfava, rinonamira uye rinoumbika. Mumwaka wokupisa, ivhu rinoserera, richibudisa pachena ivhu rakaoma, rakatsemuka.
Zvirimwa zvinobva muvhu iri
Zvinhu zvikuru zvekufunga nezvazvo paunenge uchishanda nevhu revhu mune zvekurima ndeye drainage uye acidity. Chirimwa chakanakira ivhu revhu mupunga. Donje, nzimbe nemhunga zvinokwanisa kurimwawo kana zvikaitwa zvakanaka.
Zvimwe zvirimwa zvinoshivirira asidhi uye zvisingatarisirwi, zvakaita sepineapple, rabha kana African palm, zvinogona kurimwa pane mamwe marudzi evhu revhu. Pakati pezvirimwa zvechigarire, mimwe miti yemichero inogadziriswa kune ivhu revhu. Pakati pemiti yemichero yemamiriro ekunze anodziya pane apuro, peari, quince, hazelnut uye walnut. Masango akasimwa anogonawo kuitika.
Ndinovimba kuti neruzivo urwu unogona kudzidza zvakawanda nezve ivhu revhu uye maitiro aro.