# Biomass Refined: 99% of Organic Carbon in Soils
## 1 Introduction
### Soil Organic Carbon (SOC)  
In addition to Phytomass, Soil Organic Carbon (SOC), comprising approximately half of all complex biochemicals in Soil Organic Matter (SOM), is used as a standard measure of soil biomass. Biomass is either rapidly recycled or stored and progressively consumed, decomposed, eroded, burnt, thawed, or drained--both naturally or via human activities. When considered in its entirety, the SOC stock often accumulates over varying timescales and is held to depth in several interlinked and intergrading SOC storage sub-categories:  
1. Biomass that is actively living and is then mostly recycled within short time periods;
2. Mineral soils (with <17% SOC) that store humic carbon when there is insufficient Nitrogen or other limiting factors for completed digestion by microbes (this inferred from poor agriculture that adds excess N, rapidly depleting the humic SOM stocks);
3. Pernafrost frozen to depth with seasonally thawed toposoil (with permafrost beats);
4. Non-permafrost beats that are waterlogged and too oxygen-deficient for rapid decay;
5. Fossils/fuels formed from the geological-era, anoxic accumulation of SOM products;
6. Sediments washed from watersheds or leached in Dissolved Organic Carbon (DOC). Like others, ref. [18] demonstrated soils hold the largest biogeochemically active carbon pool on Earth, albeit they noted SOC estimates ranged six-fold, from 500 to 3000 Gt C (now by factors at least \(\times\)10). Their six-fold SOC increase is interesting as it is less than a modest 4-6-fold increase invoked, and as criticized, in a meta-analysis by [16]. Similar wide errors pertain to other biomass estimates and metrics, with ranges differing inordinately, attesting to our ignorance of the basics of soil data. Soil ecological data are so remarkably obscure that values presented by many authors may differ by an order or two of magnitude, often subsequently revised upwards. For example, the global SOC stocks' range reported by [19] was 504-3000 Gt SOC; but ranges were 1417-25,000 Gt SOC (\(\times\)18) due to a statement by [20] that _\"the global SOC stock to 100 cm soil depth is estimated at 1417 Pg C\"_ compared to best estimates (with terrain) of >8000-25,000 Gt by tables 10 and 12 in ref. [16]. Already, without terrain, errors were manifest in mineral soil underestimations up to seven times [21], Permafrost by 200% or three times [22]--these base values since doubled by [16]--and total Peat SOC was further doubled [23; 24; 25]. Roots are underestimated up to 100% [26] and, for litter, ref. [27] found: _\"litter stocks based on observations (68-97 Gt C) or models (47-196 Gt C)\"_. Mainly soil Bacteria have uncertainty, as with most other Microbiota, up to 10-fold [28]. For Net Primary Productivity (NPP), estimates were 2-5 times higher, accounting for below-ground dynamics [29]. Ref. [30] discuss disparities in both satellite and model assumptions with _\"range of **two orders of magnitude** in field-measured NPP\"_ [my bolding]. Noting that _\"Solis provide humans with 98.8% of our food\"_, ref. [31] had soil erosion with a rate of loss _\"unsustainable at 10-1000 times higher than the rate at which soils form\"_ and [32] posited global land use change as \(\times\)4 greater than previously estimated. Ref. [33] had soil\(\leftrightarrow\)air CO\({}_{2}\) flux estimates varying 25-450 Gt C/yr, and discrepancy of SOC loss oxidation during erosion were 0-100% [34]. Preindustrial SOC emissions before 1850 range 48-540 Gt C (e.g., [35] and table 7 in ref. [36]) while post-industrial data also vary with conversion from natural ecosystems to SOC-depleting farmland supposedly releasing 50-200 Gt C to the Atmosphere [34; 37]. These and many other examples of wide uncertainties in a range of vitally important soil properties or rates of change attest to an urgent need for thorough review.