Biochar and poultry manure effects on soil properties and radish (Raphanus sativus L.) yield

ABSTRACT A field experiment was conducted over two years to evaluate the effects of biochar (B) and poultry manure (PM) on soil properties, leaf nutrient concentrations and root yield of radish. The experiment consisted of 3 × 3 factorial combinations of B (0, 25 and 50 t ha−1) and PM (0, 2.5 and 5.0 t ha−1). Applications of B and PM on their own, and in combination, improved soil physical and chemical properties, leaf nutrient concentrations and yield components of radish. In the second year (2016), application of B on its own increased soil pH and concentrations of organic matter, N, P, K, Ca and Mg, as well as leaf nutrient concentrations and yield, but in the first year (2015) it only increased soil pH and organic matter. In both years, application of B influenced root length of the radish significantly. There was a significant interaction effect of biochar and poultry manure, which was attributed to the ability of the B to increase the efficiency of the utilization of the nutrients in the PM. The combination of 50 t ha−1 B and 5 t ha−1 PM resulted in the highest radish yield, with increases in root weight by 193%, 252% and 252% compared with B alone at 50 t ha−1, at 25 t ha−1 and no application of B or PM, respectively. Therefore, for a short season crop like radish the expected benefit of applying B on its own without PM may not be achieved within the first year.