Ukuhlola Ukuphila Kwezinhlanzi Emanzini

© Marinda Louw
Ikhwalithi yamanzi yedamu kanye nomthombo wamanzi wamanzi (ukuhlanza amanzi okudoba amanzi) kufanele ihlolwe ngaphambi kokuqala ukulima kwezinhlanzi. Ngaso sonke isikhathi thatha amasampuli wokuhlola amanzi kusuka ezindaweni ezahlukene emadamu hhayi kusuka ogwini yedwa.

Emanzini angaphezulu: hlola lezi sampuli zamanzi zomoya, i-pH, i-nitrogen esiphelele, i-ammonia kanye ne-phosphorus (P).
Emanzini athathwa kusukela phansi kwedamu: ukuhlolwa kwe-oxygen, i-pH ne-ammonia.

Indlela Yokuhlola Amanzi Edamu

Isikhathi esihle kakhulu sokuthatha amasampula wamanzi eNtshonalanga Kapa kwakuzoba ngoNovemba kuya kuJanuwari, kusho umphathi oyinhloko wezobuchwepheshe we-Aquaculture: i-Department of Animal Sciences enyuvesi yaseStellenbosch.

Isampula yamanzi eduze nendawo (kusukela ku-1 kuya ku-2 m ubujamo obujulile) nangasemuva kwedamu ngokusebenzisa isampuli samanzi. Emadamu angajulile, thatha isampula esitokisini emodeni kanye nesinye isampula ekuphumeni.
Thatha amasampuli owodwa noma amabili noma ngaphezulu uma isabelomali sivumela; ukwenza ukuhlaziywa okuphelele kwelabhoratha kuzobiza phakathi kuka-R1 500 no-R2 000 (2019). Ivolumu yesampuli ye 350 ml izanele. Gcina efrijini futhi uhlaziye zingakapheli izinsuku ezintathu uthatha isampula, weluleka u-Stander.

Izinga Elidengekayo Ekuphileni Kwenhlanzi

©Brian Ginn, North American Lake Management Society (NALMS)
Amasampuli wamanzi ahlaziywa ngezindawo ezehlukene futhi angabandakanya ukuhlolwa kwezinsimbi ezinzima. Ikhwalithi yokuqala yamanzi (ngaphambi kokuqala ukuhlanza amanzi okudoba) kumele kube kanje:

I-oksijeni:
Umoya owanele emanzini angaphezulu: 7 kuya ku-12 mg/L.
Amazinga aphakeme kakhulu oksijini angabonisa ukukhula ngokweqile kwe-phytoplankton futhi akhulise izingozi zokuphefumula oksijini lapho i-phytoplankton ifa.

i-pH:
Amanzi angaphezulu komhlaba kufanele abe ngaphansi kuka-8 naphakathi kuka-5 no-8. Umehluko emkhatsini wamanzi angaphansi nangaphansi pH kufanele ube ngaphansi kuka-1.5.

I-Amoniya:
Amazinga e-ammonia ezansi angeke adlule u-1 mg/L.

I-TP:
Amazinga ephelele e-phosphorus (TP) emanzini angaphezulu akufanele adlule 50 μg/L (0.05 mg/L).

I-TN: TP
Isilinganiso se-nitrogen esiphelele: inani le-phosphorus (TN:TP) kufanele lidlulele okungama-20. Lokhu kuwukugwema ama-flavour inhlanzi ngenxa ye-algae taint.

Ukubonakala
Ukubonakala okuhle kufanele kube ngaphezu kuka-50 cm njengoba kutholakala nokufundwa kwe-Secchi-disc.

Translated by Nsika Khoza