The influence of alternative tillage systems on the distribution of nutrients and organic carbon in some common Western Australian Wheatbelt soils
1990
White, P.F. (Western Australian Dept. of Agriculture, South Perth. Div. of Plant Industry)
In a field experiment over 9 years on a yellow earthy sand, a calcic red-brown earth and a non-calcic brown earth continuously cropping wheat, clear differences were evident within the first 3 years, but relative differences then remained constant. The concentrations of extractable P and K, total N and organic C were all higher with direct drilling than with conventional cultivation, regardless of soil type or environment. Major differences between treatments occurred in the surface 5-10 cm of soil. Accumulation of nutrients near the surface indicated that, if the surface is dry, nutrients may be less available to plants established with direct drilling than with conventional cultivation.
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