In this article. DMSO, or dimethyl sulfoxide, is a by-product of paper making. It comes from a substance found in wood. DMSO has been used as an industrial solvent since the mid-1800s.MSO is easily absorbed by the skin. It's sometimes used to increase the body's absorption of other medications. DMSO is available without a prescription most often in gel or cream form.
Actual soil fertility is the amount of nutrients and moisture derived from the soil by the plants in a given year.
Shifting agriculture, system of cultivation that preserves soil fertility by plot (field) rotation, as distinct from crop rotation. In shifting agriculture a plot of land is cleared and cultivated for a short period of time; then it is abandoned and allowed to revert to its natural vegetation while the cultivator moves on to another plot. The period of cultivation is usually terminated when the soil shows signs of exhaustion or, more commonly, when the field is overrun by weeds.