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Participant: part of or influencing processes

Soil solution

Appears in 31 processs and 57 steps. Everything below is linked: open a process to see it in context.

Top processes

Cation exchange, pH and soil solution chemistry

8 steps

Start: Cation exchange, pH and soil solution chemistry
End: Cation exchange, pH and soil solution chemistry
Cations held on exchange sites (Ca, Mg, K, Na, NH4, Al, H)
and 5 more in this process

Phosphate sorption on Fe and Al oxides and phosphorus availability

5 steps

Nutrient availability and leaching

4 steps

Start: Nutrient availability and leaching
End: Nutrient availability and leaching
Base cation cycling (calcium, magnesium, potassium, sodium)
and 1 more in this process

Base cation cycling (calcium, magnesium, potassium, sodium)

4 steps

Clay mineral transformation sequence

4 steps

Start: Clay mineral transformation sequence
End: Clay mineral transformation sequence
Interlayer K loss opens layers; high-charge vermiculite forms
and 1 more in this process

Micronutrient availability: pH, redox and plant mobilisation of Fe and Zn

3 steps

Show 25 more processes

Living soil system

2 steps

Clay mineralogy and organic matter set cation exchange capacity

2 steps

Salinity and sodicity

2 steps

Aluminium toxicity and liming of acid soils

2 steps

Roots and rhizosphere

1 step

Depletion zone forms around root

Saprotrophic fungi

1 step

Mineral nutrients released at hyphal death

Bacteria and archaea

1 step

Soluble substrates diffuse to bacterial cells

Phosphorus cycling

1 step

Phosphate dissolved in soil solution

Humification and SOM stabilization

1 step

Humus increases cation exchange and water holding

Soil sulfur cycling

1 step

Sulfate in solution is adsorbed on Fe and Al oxides and edge sites, desorbing as pH rises

Nitrification-driven acidification of ammonium fertilised soil

1 step

Soil pH falls as acidity accumulates

Sequential soil pH buffer systems

1 step

Silicate and exchange buffer ranges (about pH 6.2 to 4.2): protons displace base cations

Iron redox cycling and the enzyme latch in wet soil

1 step

Dissolving oxides releases sorbed phosphate and organic carbon

Soil nitrogen mineralization and immobilization turnover

1 step

Ammonium pool in soil solution and on exchange sites

Root exudate chemistry, fate and priming

1 step

Exudate compounds enter soil solution with half-lives of minutes to hours

Soil nitrification, nitrate reduction and nitrogen gas losses

1 step

Nitrate pool in soil solution (mobile anion)

Mineral weathering and parent material

1 step

Clay mineral transformation sequence

Biochar and charcoal in soil

1 step

Surface oxidises, gaining carboxyl groups and CEC; pores adsorb water and nutrients

Biological nitrogen fixation: nitrogenase, oxygen protection and regulation

1 step

Fixation is limited by molybdenum, phosphorus and iron supply, and alternative V or Fe nitrogenases are less efficient

Actinomycetes: Streptomyces hyphal life cycle, extracellular enzymes and antibiotics

1 step

Resource depletion sensed: substrate mycelium partly lyses and the colony switches to aerial hyphae

Pyrite oxidation and acid sulfate weathering

1 step

Fork: does solution pH fall below about 4 (no carbonate to buffer)

Pedogenic carbonate accumulation and calcrete formation

1 step

Calcite equilibrium buffers pH at 7.5 to 8.5; phosphate precipitates as Ca phosphates and Fe, Zn and Mn availability falls

Biofilms and quorum signalling in soil microcolonies

1 step

Alkaline pH and warmth hydrolyse the AHL lactone ring, so signals persist longer in acid, cool soil

Biological nitrogen fixation: free-living and symbiotic

1 step

Nitrogenase needs molybdenum, iron and phosphorus; Mo limits free-living fixation in some tropical forest litter

Rhizosphere phosphorus mobilization: phosphatases, organic acids and fast re-sorption

1 step

Soil solution Phosphate seldom exceeds about 10 uM (often 1-2 uM), so roots deplete a zone around themselves

Often found with

Plant roots 18 Hydrogen ions 16 Clay minerals 15 Water 13 Iron oxides 10 Soil organic matter 9 Cations 8 Phosphate 8 Potassium 7 Microbes 5 Phosphorus 5 Calcium 5

Known by 719 participants and resources across the map.