Ukubaluleka koMgangatho woMhlaba

© Dr Eduard Hoffmann (Department of Soil Science, US)

Umgangatho womhlaba unegalelo ekuchumeni komhlaba, kwindlela oqina nothamba ngayo okanye okwazeka ngayo ukusebenzeka. Oku kukwaquka nokubalula kokuhlakuleka komhlaba. Ngaphezulu, umgangatho womhlaba kunye nodongwe olukuwo zezona zinto zibalulekileyo ezibonakalisa umoya osemhlabeni kunye nokukwazi kwawo ukugcina amanzi.

Umgangatho/Ubume boMhlaba

©United States Department of Agriculture
Umgangatho / ubume bomhlaba buthetha ngee particles zomhlaba. Umzekelo, iiparticles zesanti zinkulu ukodlula ezomdongwe. Iiparticles zesanti zibaphakathi kwe 0.05 to 2.0 mm, ezemvuthuluka yesanti ziphakathi kwe 0.002 ukuya kwi 0.05 mm ubukhulu logama ezomdongwe zingaphantsi kwe 0.002 mm ngokomlinganiselo. Iiparticles zegrabile okanye ezamatye zingaphezu kwe 2 mm ubukhulu kwaye azibalwa xa kujongwa ukumila nomgangatho womhlaba.
Umhlaba ungohlulwa ngokwemigangatho emine: oyisanti, santi erhabaxa/eyimvuthuluka, isanti ebukudongwarha kunye nodongwe. Umgangayo wesanti wenziwa yindlela ezidibene ngayo iiparticles ezahlukeneyo zomhlaba.
Umhlaba oyisanti uhrabaxa logama oludongwe uthambile kwaye une particles ezincinci zomdongwe. Udongwe luncangathi kwaye luqinile, ngoko ke ama 20% kuphela omdongwe angenza umhlaba uvakale/ubonakale njengomdongwe. Umhlaba onesanti, imvuthuluka/amahlalutye, kunye nomdongwe ubizwa nge ‘loam soil’. Umzekelo, umhlaba oyisanti nodongwe kunye namahlalutye uqulathe ama 30% omdongwe, 50% esanti, kunye nama 20% amahlalutye.

Indlela Yokubona Indidi Yomhlaba

Xa usentsimini, ikha umhlaba ngesandla uthi chintsi amanzi, ze ubumbe ibhola. Ukuba awunakho ukuyibumba, oko kuthetha ukuba umhlaba wakho uyisanti. Iva umhlaba ngeminwe ukuze ubone ukuba uyisanti, unamahlalutye okanye ufayini okanye ungumdongwe na.
Ilabhorethri ingahlola indidi yomhlaba, kodwa umfama angasebenzisa icebo le ‘soseji’ ukuze abone indidi yomhlaba wefama yakhe. Abaphandi be South Africa’s Water Research Commission badibanise ezinkcukacha zilandelayo nezingendlela ezilula zokubona ukumila komhlaba:
Isanti
Umhlaba oyisanti unodongwe olungaphantsi nakwi 10%. Awunakubumbeka ubeyi ‘soseji’, kodwa kuxhomekeka kwintlobo yomdongwe leyo, usenokubumbeka ube yibhola engaphasalaki msinya.
Isanti eloamy
Inamalunga ne 10-15% yodongwe. Amagaqa ayo aphakathana ngokomlinganiselo kwaye anga colwa ngeminwe. Ibumba ‘isoseji’ ikhawuleza iphasalake’.
Iloam enesanti
Inamalunga ne 15 - 20% yomdongwe. Ingenza ‘isoseji edeki kodwa ephasalakayo xa ithe yaxinzelelwa kancinane.
Iloam enesanti nomdongwe
Inama 20 - 35% omdongwe. Ingenza ‘isoseji’ kodwa iqhekeke xa uyenza unobumba u-U.
Loam yomdongwe
Iqulathe ama 27 - 40% omdongwe. Ungenzeka unobumba U, kowa iqhekeke xa usenza isangqa.
Umdongwe oyisanti
Unama 35 - 50% womdongwe. Lomhlaba ubonakala okomdongwe, kodwa unoburhabaxa xa ukhuhlwa. Uyaphasalaka xa kusenziwa isangqa.
Umdongwe
Lo mhlaba unomlinganiselo ongaphaya kwama 50% omdongwe. Wenza isangqa esizinzileyo esinga phasalakiyo. Uburhabaxa namahlalutye abubonakali kulo umhlaba.

Izityalo kunye Nomgangatho Womhlaba

©Dr David Lindbo (North Carolina State University)
Indlela amanzi atshona ngayo emhlabeni ixhomekeka kwindidi yomhlaba. Isanti emhlabeni inceda ekufunxeni amanzi nokungena komoya emhlabeni. Umhlaba oyisanti awukwazi ncam ukugcina amanzi kunomdongwe, ngoko ke amanzi kunye nesichumiso kungafuneka agalelwe rhoqo kule mihlaba yesanti ngaphezu kwaleyo yomdongwe.
Izichumiso zendalo ziyakhawuleza ukusebenza kwimihlaba enesanti eninzi, njengoko kusube kukho umoya owaneleyo emhlabeni-Ukuze ezi zichumiso zicoleke kakuhle, zidinga i-oxijin. Ngaphezulu, imihlaba enakho ukufunxa amanzi inomoya omninzi, nto leyo iye ibe negalelo kwimpilo yezityalo.
Imihlaba enomdongwe omninzi ingagcina izinongo ezininzi kunye namanzi. Iiparticles zomhlaba oludongwe zibanee ions kwaye zingakwazi ukugcina zifunxe ii-elementi ezifana ne ammonium (nitrogen-compound), potaziyam, calcium, magnesium kunye namanye amasuntswana ee-elementi. Indlela umhlaba okwazi ngayo ukugcina umgangatho omnye we pH uxhomekeka kwizichumiso zendalo ezikhoyo kunye ne nomdongwe okhoyo. Imihlaba eloamy ibonwa nje ngeyona mihlaba izilungeleyo izityalo ezininzi.

Ukuphucula Ukumila/Nomgangatho Womhlaba

Imihlaba eyisanti kunye nengumdongwe ingaphuculwa ngokuthu kugalelwe izichumiso zendalo ezifana nomgquba, iintsalela zezityalo, imanyolo yobulongwe, amagqabi amadala, kunye namaxolo emifuno.

Translated by Zizipho Silwana