Ịgbapụta mmiri (ọrụ ugbo)

N'ọrụ ugbo, leaching bụ ọnwụ nke Ihe oriri na-edozi ahụ site na mmiri site na ala, n'ihi Mmiri ozuzo na ịgba mmiri. A na-eburu n'uche Ọdịdị ala, ịkụ ihe ọkụkụ, ụdị na itinye fatịlaịza, na ihe ndị ọzọ iji zere oke mmebi nri. Mmiri na-agbapụta pụkwara izo aka n'omume nke itinye obere ịgba mmiri n'ime ala ebe mmiri nwere nnu dị elu iji zere nnu site na iwulite n'imeala (Nchịkwa nnu). N'ebe a na-eme nke a, a ga-ejikarị drainage mee ihe, iji buru mmiri karịrị akarị.

Mmiri na-agbapụta bụ nchegbu sitere n'okike mgbe ọ na-enye aka na mmetọ Mmiri dị n'okpuru ala. Ka mmiri sitere na mmiri ozuzo, idei mmiri, ma ọ bụ isi iyi ndị ọzọ na-abanye n'ime ala, ọ nwere ike ịgbaze kemịkal ma buru ha banye n'ime mmiri dị n'okpuru ala. Ihe nchegbu pụrụ iche bụ ebe a na-ekpofu ahịhịa na ebe a na'ebe a na-atụfu ihe, na, n'ọrụ ugbo, fatịlaịza gabigara ókè, nsị anụmanụ echekwara n'ụzọ na-ekwesịghị ekwesị, na biocides (dịka Ọgwụ ahụhụ, Ọgwụ fungicides, ọgwụ ahụhụ na ọgwụ herbicides).

 Nitrogen na-agbapụta 
Nitrogen bụ ihe a na-ahụkarị na okike na ihe ọkụkụ dị mkpa. Ihe dị ka 78% nke ikuku ụwa bụ nitrogen (N2). Njikọ siri ike dị n'etiti atọm nke N2 na-eme ka gas a bụrụ ihe na-adịghị agwụ agwụ na ọ bụghị ihe ọkụkụ na anụmanụ ga-eji ya eme ihe ozugbo. Ka nitrogen na-agbagharị n'ikuku, mmiri na ala, ọ na-enwe mgbanwe dị iche iche nke kemịkalụ na ndu. Nitrogen na-akwalite uto osisi. Anụ ụlọ na-erikwa ihe ọkụkụ ndị na-amịpụta nri, bụ́ nke a na-eweghachi n'ala, na-agbakwụnye ụdị nitrogen na organic na mineral. Ọkpụkpụ a na-agwụcha mgbe ihe ọkụkụ na-esote na-eji ala emeziri.[1] Iji mee ka mmepụta nri dịkwuo elu, a na-ewebata fatịlaịza, dị ka nitrate (NO3-) na ammonium (NH4+), nke osisi na-amịkọrọ ngwa ngwa, na mpaghara mgbọrọgwụ osisi. Otú ọ dị, ala adịghị amịkọrọ ihe karịrị ion NO3- ion, nke na-eji mmiri na-asọpụta na-agbada n'enweghị ihe ọ bụla, na-abanyekwa n'ime mmiri ala, iyi na oké osimiri.[2]. Ọkwa leaching na-emetụta:

 soil type and structure. For example, sandy soil holds little water while clay soils have high water-retention rates;
 the amount of water used by the plants/crops;
 how much nitrate is already present in the soil.

Ọnọdụ nke nitrous oxide (N2) na ikuku nke ụwa na-abawanye na 0.2 ruo 0.3% kwa afọ. Isi iyi nke nitrogen sitere n'aka mmadụ bụ 50% karịa site na isi mmalite okike, dị ka, ala na oké osimiri. Ihe ndị a na-etinye n'ọrụ ugbo, ya bụ fatịlaịza na nsị, na-akpata 75% nke isi iyi nitrogen sitere n'aka mmadụ. Òtù Nri na Ọrụ Ugbo nke Mba Ndị Dị n'Otu (FAO) na-eme atụmatụ na ọchịchọ ụwa maka fatịlaịza nitrogen ga-abawanye site na 1.7% kwa afọ n'etiti afọ 2011 na 2015. Mmụba nke nde tọn 7.5. A na-atụ anya na mmụba Nri nitrogen fatịlaịza na mpaghara ga-abụ 67% site na Eshia, 18% site na Amerịka, 10% site na Europe, 3% site na Africa, na 1% site na Oceania.FAO, Current world fertilizer trends and outlook to 2015

 Ọpụpụ phosphorus 
Phosphorus (P) bụ isi ihe na-edozi ahụ gbasara eutrophication nke mmiri dị n'elu ma egosiri na ọ na-egbochi uto algae na gburugburu ọdọ mmiri. Ọ dịla anya a ghọtara mfu P site n'ubi a na-akọ dị ka otu n'ime ihe iyi egwu na-ebute ogo mmiri dị n'elu.[6] Leaching bụ ụzọ njem dị mkpa maka mfu P si n'ubi a na-akọ ugbo na mpaghara ndị nwere larịị nwere ala aja ma ọ bụ ala na-enwekarị ike iru mmiri.[7] N'adịghị ka nitrogen phosphorus na-emekọrịta ihe na ụmụ irighiri ihe nke ala site na adsorption na desorption. Ebe mgbasa ozi dị mkpa maka P na ala bụ elu igwe na aluminom oxides ma ọ bụ hydroxides dị ka gibbsite ma ọ bụ ferrihydrite. Ala, ọkachasị ndị bara ụba na mineral ndị dị otú a nwere ike ịchekwa P agbakwunyere na fatịlaịza ma ọ bụ nri. Adsorbed P na-eguzo n'ụzọ dị mgbagwoju anya na P na ngwọta ala nke ọtụtụ ihe dị iche iche na-achịkwa dị ka:

 nnweta nke ebe adsorption;
 ọnụ ọgụgụ nke phosphorus na anions ndị ọzọ na mmiri mmiri ala;
 pH ala;
 ikIke redox ala.  Börling, Katarina (2003). Phosphorus sorption, accumulation and leaching. Diss. Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae. Agraria, 1401-6249 ; 428Schoumans, O. (2015). Phosphorus leaching from soils: process description, risk assessment and mitigation. Diss. Wageningen University and Research Centre.

Phosphorus ga-agbapụta mgbe a na-agbanwe nha nha nke na ma ọ bụrụ na agbakwunyere P na mbụ ka ewepụtara ya na ngwọta ala ma ọ bụ enweghị ike ịgbanye P ọzọ. Ọtụtụ ala ndị a na-akọ na-enweta fatịlaịza ma ọ bụ nri P n'ọtụtụ ugboro karịa ihe ọkụkụ a chọrọ na nke a na-abụkarị ọtụtụ iri afọ. Phosphorus agbakwunyere na ala ndị dị otú ahụ na-agbapụta naanị n'ihi na ọtụtụ saịtị mgbasa ozi nwere ike ịbụ ntinye P sitere n'oge gara aga, nke a na-akpọ "phosphorus legacy".[9][10] Enwere ike ịkpata ntachi nke P site na mgbanwe ọnọdụ kemịkalụ na ala. Mbelata na ala redox ikike n'ihi ogologo mmiri saturation nwere ike iduga mbelata mgbasa nke ferric ígwè mineral ndị dị mkpa P sorption saịtị. N'ihi ya, a na-ahapụ phosphorus na mineral ndị a n'ime ngwọta ala ma nwee ike ịgbanye ya. Usoro a na-enwe nchegbu pụrụ iche na mweghachi nke ala mmiri dị n'okike bụ nke a na-ekpochapụ na mbụ maka mmepụta ugbo.

 Mmetụta ahụike 
Ọkwa dị elu nke NO3 n'ime mmiri nwere ike imetụta ọkwa oxygen n'ụzọ dị njọ maka ma mmadụ ma usoro mmiri. Ihe gbasara ahụike mmadụ gụnyere methemoglobinemia na anoxia, nke a na-akpọkarị ọrịa na-acha anụnụ anụnụ. N'ihi mmetụta ndị a na-egbu egbu, ụlọ ọrụ nchịkwa na-amachi oke NO3 kwere na mmiri ọṅụṅụ na 45 ruo 50 mg kwa liter. Eutrophication, mbelata nke ikuku oxygen nke mmiri, nke sistemu mmiri nwere ike ibute ọnwụ azụ na ụdị mmiri ndị ọzọ. N'ikpeazụ, ntanye nke NO3 site na isi mmalite acid nwere ike ịbawanye mfu nke calcium na nri ala ndị ọzọ, si otú ahụ belata mmepụta ihe gburugburu ebe obibi.

 Hụkwa 

 Ịgbapụta mmiri (nkụzi) 
 Ihe nlereanya nke ịpụ n'ala
 Nchịkwa nnu nke ala (ihe achọrọ maka ịgbapụta, arụmọrụ ịgbapụta) 
 SahysMod (spatial agro-hydro salinity, leaching na ụdị mmiri dị n'okpuru ala) 

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