Impact of biochar application on the productivity of a temperate vegetable cropping system

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 fertilizer rate treatments (either half or full 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.