Effect of subsoil friability in Lemons loam on the growth of peach trees

Abstract

Lemnos loam, a widespread red-brown earth soil type in the Goulburn Valley, Victoria, has been re-surveyed in an area of approximately 6,880 hectares near Kyabram. Three degrees of subsoil friability have been recognised and mapped. The root distribution, butt circumference and height of ten year old peach trees (Golden Queen and Cornish varieties) have been studied In relationship to these degrees of friability. The results obtained show that the greater the friability of the subsoil, the better is tree performance as measured by butt circumference and tree height. Furthermore, the greater the friabihty of the subsoil, the deeper is the penetration of roots into the subsoil layers and the higher is the root concentration in the deeper horizons of the soil. A regression equation, with a coefficient of determination of 89.7 per cent, has been obtained for the relationship between total root length in the subsoil and butt circumference.