Digging heavier soils in the autumn, leaving as rough as possible to aid “weathering”; The addition of “bulky organic matter”; Short manure (well-rotted) to light sand soils to bind it together in the first case (physical effect) then becoming Humus (glue); Long manure (half rotted) to open up heavy soils in the first case (physical effect) then becoming Humus; Subsoiling to improve drainage and to break up soil pans (chemical (iron) or cultural plough pan). Garden methods: deep digging and installing drainage; Addition of lime to heavy soils to flocculate the colloids (hydrated lime will alter the soil Ph, gypsum will not); Spiking or tining of lawns for aeration and root penetration; Addition of grit or coarse sand to heavier soils and digging in. Tends to improve surface penetration and surface drainage (but limited effect if the movement of water is impeded).