Oxidation and Reduction
Oxidation and reduction are important to understand due to their relation to disease enhancement or suppression.
Disease enhancing soils tend towards oxidizing, alkalinity, nitrogen as nitrates, with poor biology.
Disease suppressive soils tend towards reducing, acidifying, nitrogen as ammonium, with aggressive biology
pH: Proton transfer potential – Scale from 0 to 14
Redox potential, Eh: Electron transfer potential – Scale from 0 (reduction) to 48 (oxidation)
“It is worth reviewing that the main constituents of living organisms, especially proteins, are just six elements: (i) oxygen; the strongest oxidizing agent; (ii) hydrogen; the strongest reducing agent; and (iii) the four elements that have the largest amplitude in redox numbers: carbon (−IV in CH4 to + IV in CO2), nitrogen (−III in NH 4 + to + V in NO 3 – ), phosphorus (−III in PH3 to + V in PO 4 3- ), and sulfur (−II in H2S to + VI in SO 4 2- ).” https://link.springer.com/article/10.1007/s11104-012-1429-7
Redox reactions describe the movement of electrons from one ion to another. The term RedOx comes from the two processes that occur during a reaction: REDuction and OXidation. These reactions occur together, they cannot occur separately.
eH determines anion availability.
eH is not stable like pH. It moves all the time, for example with soil saturation
Oxidized soils are electron hungry. If you put a reduced substance into them, the electrons will be stripped.
Rainy periods are a reducing environment / dry periods are an oxidizing environment
Mn, Fe, Cu, Co (but not Zn) are absorbed and active in the reduced form
Cultivation causes a CO2 release due to oxidation. Also strong bacterial digestion will cause a CO2 release.
Reduced environments: anaerobic fermentation, blueberry or cranberry bogs, bokashi
Reduced and acidic systems usually correlate in biological systems. This is not necessarily true in chemistry.
Blueberries need very reduced environments because they need Mn, Fe, P.
It’s important to know the biological state.
N, P, S have large redux swings
Ammonium is the reduced form of N. Oxidized forms are No3 and nitrate.
Dry soil becomes oxidized.
Salt fertilizers such as KSO4 are oxidizing. We need to include reducing effects.
We need to move the system from oxidizing to reducing.
Disease suppressive soils are slightly reducing in eH. Neither aerobic nor anaerobic dominant. Facultative microbes are defined as those who can produce ATP using an oxygen pathway when present or anaerobically when not. These include human diseases such as strep, staff, e coli, salmonella. Another, Shewanella oneidensis, is able to strip electrons from metals and convert them to a reduced form.
Plants with reducing roots include non-GMO corn, alfalfa, forage legumes, oats, buckwheat, brassicas.
Plants with oxidizing roots include wheat, GM corn, soybeans
High glucosomate mustard or mustard seed are highly reducing.
A diverse ecosystem moves things towards a healthy, reducing environment.
Healthy manure is reducing
Milk house waste in manure is related to disease.