The soil is worked to a depth of two spades, rather than one, and it’s essential to keep the two layers of soil (subsoil and topsoil) separate. In order to do this, the lower half of the trench ...

The iron and aluminium oxides collect in the 'B' horizon where the iron oxides can accumulate to form a thin layer of hardpan, which impedes drainage through the soil. Illuviation is the process ...

The Earth's interior is composed of four layers, three solid and one liquid—not magma but molten metal, nearly as hot as the surface of the sun. The deepest layer is a solid iron ball, about ...

“Running that horizontal tillage tool created a soil density layer beneath the surface,” he says. In scientific terms, the bulk density of the tilled soil (the dry weight of soil divided by ...

For a long time, soil was all but ignored. But for years, the valuable humus layer has been thinning. Farmers in Brandenburg ...