Effects of Maize-Straw Biochar and NPK Fertiliser on Groundnut (Arachis Hypogaea L.) Yield and Soil Loss During Harvesting

Abstract

Information on the effects of biochar on soil loss associated with groundnut harvesting remains limited. Hence, a 3 × 3 factorial field experiment arranged in a Randomised Complete Block Design (RCBD) with three replications, consisting of three rates of maize-straw biochar (0, 3 and 6 t ha⁻¹) and NPK 15:15:15 fertiliser (0, 30 and 60 kg N ha⁻¹), was conducted at the Teaching and Research Farm, University of Ibadan, Ibadan, Nigeria, to examine the effects of biochar, NPK 15:15:15 fertiliser and their interaction on groundnut yield, soil loss associated with crop harvesting, soil nutrient loss and post-harvest soil physical properties. The results showed that biochar application did not significantly (P > 0.05) affect groundnut pod yield, specific soil loss due to crop harvesting (SLCHspec), total soil nutrient loss or post-harvest soil physical properties. NPK 15:15:15 fertiliser significantly (P < 0.05) affected groundnut pod yield and total soil loss due to crop harvesting (SLCHcrop), while the interaction between biochar and NPK 15:15:15 fertiliser significantly influenced groundnut pod yield and SLCHcrop. The highest pod yield (2.97 t ha⁻¹) was obtained from the combined application of 6 t ha⁻¹ maize-straw biochar and 0 kg ha⁻¹ NPK 15:15:15 fertiliser, whereas the highest SLCHcrop (8.13 kg ha⁻¹) was recorded under the same treatment combination. Biochar application produced numerical improvements in field capacity, bulk density and saturated hydraulic conductivity. The interaction between biochar and NPK fertiliser significantly influenced saturated hydraulic conductivity.