The Historic Loss of Soil Carbon The world’s soils have been losing SOC for thousands of years, since the early days of agriculture and the advent of the plough. [...] The New Paradigm The Slow Death of Soil Humush If recalcitrance of an input is not the key factor in determining how long and how much carbon stays in soil, then what is? The answer seems to arise from the day-to-day activities of the soil microbes who consume the carbon. [...] So, what is soil humus? Carbon enters the soil in a variety of forms that range from extremely labile to extremely recalcitrant, but how much C stays in the soil for the long term (the factor that, along with the quantity of C inputs, really determines sequestration levels) is not a direct function of the chemical nature of those inputs; rather, it is a function of the size, diversity, and health. [...] • Using the bulk density and the volume, an estimate of the total weight of the soil in the sampled area is calculated. [...] Agricultural croplands and pastures show the greatest potential due to the substantial land area devoted to this soil use, the successes to date in Western Canada (illustrating the large-scale do-ability), and the significant carbon deficits that exist in soils in the rest of the country.
- Pages
- 89
- Published in
- Canada
