Search / resource

Resource: used or used up in processes

Ammonium

Appears in 43 processs and 94 steps. Everything below is linked: open a process to see it in context.

Top processes

Soil nitrification, nitrate reduction and nitrogen gas losses

10 steps

Which ammonia oxidizer dominates this soil?
Archaea oxidize ammonia at low supply and in acid soils
Bacteria oxidize ammonia where ammonium is plentiful
and 7 more in this process

Bacteria and archaea

7 steps

Organic nitrogen mineralized to ammonium
Ammonia-oxidizing bacteria and archaea oxidize ammonium to nitrite
Nitrogen fixation by free-living and symbiotic bacteria
and 4 more in this process

Nitrogen cycling

7 steps

Soil nitrogen mineralization and immobilization turnover

6 steps

Biological uptake, litter return and mineralization

4 steps

Roots and mycorrhizal fungi take up nutrients from soil solution
Net mineralization releases inorganic N and P
Microbes immobilize nutrients in their biomass
and 1 more in this process

Predator-prey nitrogen release (microbial loop)

4 steps

Show 37 more processes

Biological nitrogen fixation: nitrogenase, oxygen protection and regulation

4 steps

Cation exchange, pH and soil solution chemistry

3 steps

Soil food web energy transfer

3 steps

Nutrient availability and leaching

3 steps

Soil fauna

2 steps

Living soil system

2 steps

Exudate priming and microbial nitrogen mining

2 steps

Soil disturbance (fire, tillage, drought) and recovery

2 steps

Soil viruses and bacteriophages: lysis, lysogeny and the viral shunt

2 steps

Biological nitrogen fixation: free-living and symbiotic

2 steps

Nematode feeding groups, the c-p scale and nitrogen release

2 steps

Earthworm drilosphere: gut passage, casts, middens and greenhouse gas effects

2 steps

Litter quality and soil fertility reinforcing loop

2 steps

Nitrogen fixation supply-demand feedback

2 steps

Organic matter decomposition

1 step

Nitrogen immobilization or net mineralization

Biological coupling: organic matter and soil food web

1 step

Predators graze microbes (protozoa, nematodes) and release nutrients

Nutrient cycling

1 step

Nitrogen cycling

Nitrification-driven acidification of ammonium fertilised soil

1 step

Ammonia oxidisers convert Ammonium to nitrite, releasing H+

Clay mineralogy and organic matter set cation exchange capacity

1 step

Higher CEC retains Ca, Mg, K and NH4 against leaching

Mycorrhizal nutrient trade: phosphorus, nitrogen and carbon market

1 step

Nitrogen: ammonium assimilated into arginine in hyphae, carried, then broken down in the arbuscule

Methane oxidation by methanotrophs: the upland soil sink

1 step

Ammonium inhibits methane oxidation because the two substrates compete at the same enzyme family and nitrifiers co-oxidise

Actinomycetes: Streptomyces hyphal life cycle, extracellular enzymes and antibiotics

1 step

Frankia fixes N2 in actinorhizal nodules (alder, Casuarina), using vesicles with a hopanoid lipid envelope as oxygen barrier

Soil-atmosphere exchange of methane and nitrous oxide

1 step

Methane uptake is limited by diffusion: wet or compacted soil slows uptake, ammonium fertiliser inhibits it

Rhizobia-legume signalling and nodule formation

1 step

The nodule fixes Dinitrogen and delivers ammonium-derived amino acids to the plant

Viral shunt: phage lysis recycles bacterial carbon and nitrogen

1 step

Surviving microbes take up the lysate and mineralize part of it; the rest sorbs to minerals or becomes necromass (the viral shunt)

Soil respiration: temperature and moisture control and climate feedback

1 step

Rewetting dry soil causes a CO2 and mineral N pulse within hours (Birch effect) from released osmolytes and exposed organic matter

Aerenchyma, radial oxygen loss and the oxidised rhizosphere of wetland plants

1 step

In the oxic zone nitrifiers make nitrate that diffuses to anoxic soil and is denitrified, so a large share of applied nitrogen (an estimated 20 to 50 percent) is lost

Nematode feeding guilds and control of root feeders

1 step

Bacterivorous nematodes excrete ammonium because bacteria are N-rich prey; nematodes account for roughly 5-20% of net N mineralization (wide range)

Springtail and mite grazing of fungi: stimulation, defence and dispersal

1 step

Grazing mineralizes nitrogen held in fungal biomass; fauna as a whole contribute roughly a third of N mineralization in studied agroecosystems (estimate)

Earthworm gut passage, casts and the drilosphere

1 step

Fresh casts hold more ammonium, nitrate, available phosphorus and microbial activity than bulk soil

Microarthropods: springtails and oribatid mites as fungal grazers and litter processors

1 step

Grazers release ammonium and phosphate; soil animals together are estimated to supply on the order of 10-40% of N mineralisation

Soil protists: flagellates, amoebae and ciliates as selective bacterial grazers

1 step

Surplus nitrogen from bacterial prey is excreted as ammonium, and grazed rhizosphere communities favour auxin-producing bacteria that branch roots

White-rot and brown-rot fungi: two routes to lignin and cellulose decay

1 step

Mineral nitrogen released as litter decays represses ligninolytic enzymes and phenol oxidase in lignin-rich litter, slowing late-stage decay while speeding early cellulose decay

Biological soil crusts: cyanobacteria, lichens and mosses on dryland surfaces

1 step

Fixed nitrogen leaks as ammonium and amino acids to the soil beneath and neighbouring plants and microbes

Predatory bacteria: Bdellovibrio and Myxococcus hunting soil prey

1 step

Prey remains return carbon and nitrogen to the soluble pool; predators hold part as biomass

Progressive nitrogen limitation under rising CO2

1 step

Mineral nitrogen available to plants declines

Vegetation, snow, albedo and carbon feedbacks across scales

1 step

Warm winter soil speeds microbial decomposition and nitrogen mineralisation

Often found with

Nitrogen 32 Nitrate 27 Soil microbes 22 Carbon 16 Plant roots 13 Oxygen 12 Dinitrogen 9 Water 9 Rhizobia 8 Plants 8 Nitrifying bacteria 7 Phosphorus 7

Known by 719 participants and resources across the map.