NITROGEN NITROGEN CYCLECYCLE

Explains how Explains how NITROGENNITROGEN moves moves through an ecosystem.through an ecosystem.

AtmAtm. Is 78% Nitrogen. Is 78% Nitrogen NOTNOT in an immediately usable in an immediately usable

form.form. Must be Must be CONVERTEDCONVERTED into usable into usable

compounds for use by plants and compounds for use by plants and animals.animals.

4 PART Nitrogen 4 PART Nitrogen CYCLECYCLE

1. NITROGEN FIXATION1. NITROGEN FIXATION== The process of converting The process of converting

N gas to Ammonium ions.N gas to Ammonium ions.Accomplished by “Nitrogen Accomplished by “Nitrogen

Fixing Bacteria”Fixing Bacteria”

WHERE ARE THE WHERE ARE THE BACTERIA?BACTERIA?

IN SOILIN SOILIN NODULES (LEGUMES) IN NODULES (LEGUMES)

OF ROOTSOF ROOTSEX. OF LEGUMES: ALFALFA, EX. OF LEGUMES: ALFALFA,

PEANUTS, CLOVER,,PEASPEANUTS, CLOVER,,PEAS

NN2 2 gas converted to NHgas converted to NH44++

(ammonium ions)(ammonium ions)IONS released into SOILIONS released into SOILIONS released into roots IONS released into roots of bacteria’s host plantof bacteria’s host plant

IONS then used to IONS then used to make organic make organic compoundscompounds

Which helps the Which helps the PLANT GROWPLANT GROW

2. NITRIFICATION2. NITRIFICATIONNHNH44

++(AMMONIUM IONS) are (AMMONIUM IONS) are changed into NITRITES (NOchanged into NITRITES (NO22

--) ) or NITRATE (NOor NITRATE (NO33

--))Again this is used in the plant Again this is used in the plant

to MAKE ORGANIC to MAKE ORGANIC PRODUCTSPRODUCTS

3. AMMONIFICATION3. AMMONIFICATIONBREAKING DOWN NITROGEN BREAKING DOWN NITROGEN

CoMPounDS IN THE REMAINS CoMPounDS IN THE REMAINS OF ORGANISMS INTO OF ORGANISMS INTO AMMONIA (NHAMMONIA (NH33))

PERFORMED BY PERFORMED BY DECOMPOSERS (bacteria DECOMPOSERS (bacteria and fungi)and fungi)

4. DE-4. DE-NITRIFICATIONNITRIFICATION

Conversion of NHConversion of NH33, NO, NO22--, ,

or NOor NO33- - into free into free N N22

GASGAS and released back and released back into the atmosphere.into the atmosphere.

Performed by Performed by BACTERIABACTERIA in the SOIL in the SOIL