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Producing robust seedlings for forest plantation establishment is important as early growth influences potential yield and propagation is a significant budget component. The reputed benefits of biochar as a soil amendment may assist the growth and establishment of seedlings while simultaneously allowing for a reduction in fertiliser application. This study focussed on biochar's influence on the establishment of Eucalyptus nitens seedlings, changes to soil and plant chemistry and biomass accumulation. Eight doses of macadamia biochar (0-100 t ha -1 ) combined with two fertiliser rates were applied in a glasshouse pot trial and a 2-year field experiment. Soil Colwell potassium, sodium and nitrogen levels increased in response to biochar treatments while calcium, magnesium and manganese decreased. While soil nutrient dynamics varied under biochar treatments in both experiments, seedling growth did not reveal clear trends in response to biochar application.

Few studies have investigated the potential of biochar in supporting cool temperate horticultural systems with fertile soils. We examined the effects of applying 10 t ha−1 of blue mallee (Eucalyptus polybractea) biochar in combination with fertiliser rate treatments (either full or half the regional recommended rate) on crop yield, yield parameters and soil properties of a cool temperate vegetable cropping system on a red Ferrosol. Biochar amendment did not improve crop yield or other yield parameters of cauliflower, peas and broccoli crops. Similarly, soil parameters including nitrate and ammonium were unaffected by biochar treatment. We suggest the lack of biochar effect on crop and soil parameters was related to the inherent chemical fertility and structural robustness of Ferrosols, which may have mitigated any potential benefits from biochar amendment. Our results demonstrate that biochar application may not bring significant soil quality and crop productivity improvements to high-input agricultural systems.