Deep-placing lime on sandplain may lift yields

摘要

A PHYSICAL hardpan and subsurface acidity (aluminium toxicity) are two major problems occur-ring in the 10- to 35-centimetre zone of sandplain soils commonly used for cropping in Western Australia. Both prevent crop roots growing deeper into soil, reducing uptake of water and nutrients below 35cm and resulting often in reduced grain yields. There are two proven solutions Deep-ripping every three to five years ameliorates the physical hardpan. Applying sufficient lime to the topsoil to raise pH to 5.5 or greater in the top about 10cm of soil ameliorates subsurface acidity but may take several years to do so.