Maitiro Ekutenderera kweNitrogen: Hupenyu Hwechisikigo Hwakabatana
Kutenderera kwenitrogen ndeimwe yematanho akakosha e biogeochemical paNyika, anosanganisira kufamba kwenitrogen mumhando dzakasiyana dzemakemikari pakati pemhepo, ivhu, mvura, uye zvipenyu. Nitrogen chinhu chakakosha, chinoita inenge 78% yemhepo yepasi iri muchimiro chegasi renitrogen (N2). Kunyangwe yakawanda, rudzi urwu rwenitrogen harugone kushandiswa zvakananga nezvipenyu. Nokudaro, kutenderera kwenitrogen kunoita basa rakakosha mukushandura nitrogen yemumhepo kuita mafomu anoshandiswa nezvirimwa nemhuka. Chinyorwa chino chichaongorora matanho makuru ekutenderera kwenitrogen.
### 1. Kugadzika kweNitrogen (Kugadzika kweNitrogen)
Danho rekutanga mu nitrogen cycle ndeye nitrogen fixation, iyo nzira iyo mhepo ye nitrogen gasi (N2) inoshandurwa kuita ammonia (NH3) kuburikidza nekushanda kwezvipembenene kana kuburikidza nemaitiro asina kugadzikana akadai semheni.
Kune mhando mbiri huru dzekugadzirisa nitrogen:
– Kugadzika Kwezvinhu Muviri: Kunobatwa nemabhakitiriya akati wandei, kusanganisira erudzi rweRhizobium, anogara mumagunduru emidzi yembeu dzakadai sebhinzi nealfalfa. Mabhakitiriya aya ane enzyme inonzi nitrogenase, iyo inogona kuputsa zvisungo zvakasimba pakati pemaatomu enitrogen muN2 uye kuishandura kuita ammonia.
– Kugadzika kweAbiotic: Maitiro aya anoitika zvakasikwa kuburikidza nemheni inopa simba rakakwana rekupwanya chisungo cheN2 kuita maatomu enitrogen ega ega, ayo anobva aita pamwe chete neokisijeni mumhepo kuti agadzire nitrite nenitrate izvo zvinotakurwa pasi nemvura.
### 2. Kuumbwa kweAmoni (Kuumbwa kweAmoni)
Kupatsanurwa kweammonia, kunozivikanwawo sekuora kana kuti mineralization, inzira iyo zvinhu zvakafa, zvingave zvirimwa kana mhuka, zvinoputswa nesaprophytic microorganisms, zvichigadzira ammonia (NH3) kana ammonium ions (NH4+). Zvinhu izvi zvinosanganisira mapuroteni, DNA, nezvimwe zvinhu zvine nitrogen munyama mhenyu. Kana zvipenyu zvikafa uye kuora kukaitika, nitrogen iri muzvinhu zvipenyu inodzorerwa muvhu seammonia, iyo inogona kushandiswazve nezvirimwa.
### 3. Kuisa Nitrification muropa
Nitrification inzira ine matanho maviri inoshandura ammonia (NH3) kana ammonium ions (NH4+) kuita nitrite (NO2-) uye yozopedzisira yava nitrate (NO3-). Maitiro aya anoitwa nebhakitiriya rinoita nitrifying:
– Danho rekutanga: Kubviswa kweammonia kuita nitrite nebhakitiriya rinonzi Nitrosomonas.
– NH3 + O2 → NO2- + H2O + H+
– Danho rechipiri: Kuwedzera oxidation ye nitrite kuita nitrate nemabhakitiriya akasiyana, akadai seNitrobacter.
– NO2- + 1/2 O2 → NO3-
Nitrate inobuda inogona kutorwa nemidzi yemiti sechikafu chakakosha kana kudzorerwa mugasi re nitrogen, zvichienderana nemamiriro ekunze.
### 4. Kubatanidzwa
Kubatanidzwa inzira iyo zvirimwa zvinotora nitrate (NO3-) kana ammonium (NH4+) kubva muvhu kuburikidza nemidzi yazvo. Nitrate inonyudzwa inoshandurwa kuita ammonia neenzyme nitrate reductase mumasero emiti. Ammonia iyi inoshandiswa kugadzira amino acids, nucleotides, uye mamwe macompounds ane nitrogen anodiwa pakukura nekukura kwemiti. Maitiro aya anopawo sosi yakakosha yenitrogen kumhuka dzinodya zvirimwa izvi, zvichiwedzera kuyerera kwenitrogen kusvika padanho retrophic mu ecosystem.
### 5. Kubvisa ganda kubva muropa
Kubvisa hunyoro (denitrification) inzira iyo nitrate (NO3-) inoshandurwa kuita nitrogen gas (N2) kana nitrous oxide gas (N2O) kuburikidza nemaitiro akasiyana-siyana ekusashanda zvakanaka kwemuviri anoitwa nekubvisa hunyoro hwemuviri, akadai sePseudomonas neClostridium.
– NO3- → NO2- → NO → N2O → N2 (g)
Kubvisa huturu hwemvura mumuviri kunoitika zvakanyanya kana pasina mhepo inodziya, senge muvhu rakazara nemvura kana mumirwi yetsvina yeorganic. Maitiro aya akakosha nekuti anobatsira kudzivirira kuunganidzwa kwakanyanya kwenitrates mu ecosystem, izvo zvinogona kukonzera kuzara kwemvura muminda.
### 6. Basa reVanhu muNitrogen Cycle
Mabasa evanhu ane simba guru pakutenderera kwenitrogen yechisikigo. Kushandiswa kwefetereza yenitrogen yakagadzirwa mukurima kunobatsira kuwedzera kugadzika kwenitrogen, asiwo kunobatsira mukusvibiswa kwezvakatipoteredza kuburikidza nekuyerera kwemvura kunogona kukonzera eutrophic muminda yemvura. Kupiswa kwemafuta efossil uye mabasa emaindasitiri zvinogadzirawo nitrogen oxides, iyo inobatsira mukusvibiswa kwemhepo, mvura ine acid, uye shanduko yemamiriro ekunze.
### Mhedziso
Kutenderera kwenitrogen muenzaniso wakakwana wekuti zvinhu zvakakosha zvinofamba sei muzvisikwa, zvichivimbisa kuenzana kunoita kuti hupenyu hubudirire. Kubva pakugadzika kwenitrogen, ammonification, nitrification, assimilation, uye denitrification, danho rega rega rinoita basa rakabatana uye rinokosha. Kunzwisisa nekukoshesa kuoma kwedenderedzwa renitrogen hakungokoshi chete kusainzi yezvakatipoteredza asiwo kune zvatinoedza kuita kuti titarisire zviwanikwa zvechisikigo nenzvimbo zvakatikomberedza nenzira inochengetedza nharaunda. Nekuziva kukuru kwedenderedzwa iri, tinogona kutora matanho ekuderedza migumisiro yakaipa yemabasa evanhu uye kuchengetedza kuenzana kwechisikigo kwezvakatipoteredza zvedu.
