|Rapid infestation of Northern Rivers farmland|
Numerous and varied are the descriptions of how older camphor laurels spoil the soil under their canopy. The soil turns sour is the most commonly heard statement by graziers and retired farmers who have had to deal with the problem, as trees age; the degradation of soil chemistry and its texture can last many years.
That so much fine red volcanic soil country is presently covered up by camphor trees, especially in areas like Federal-Eureka where soil depth is known to be some of the best (quality) in the entire country, is not totally logical.
Concerned agriculturists and earthmoving specialists cannot comprehend how NSW Agriculture turns a blind eye to the degradation and effective loss of prime rural lands (under camphor) when in fact by Act of Parliament, in NSW Agriculture's charter, it is part of that Department's responsibility to protect our best soils.
The extent and depth of soil degradation under and near camphor trees is said to be quite proportional to the age, and hence, diameter of the mature trees. Similarly, soil closest to camphor tree butts is most likely to be 'soured', be puggy or lack good crumb structure, and be pungent-smelling as a result of camphor and other chemical exudates. Certain chemotypes of camphor laurel even keep grass and vine species from growing under or onto the tree butts, and older trees may have an entirely clear area with nil vegetation for up to 5 metres radius underneath particularly shady camphors.