title: Soil properties, greenhouse gas emissions and crop yield under compost, biochar and co-composted biochar in two tropical agronomic systems.
abstract: The addition of organic amendments to agricultural soils has the potential to increase crop yields, reduce dependence on inorganic fertilizers and improve soil condition and resilience. We evaluated the effect of biochar (B), compost (C) and co-composted biochar (COMBI) on the soil properties, crop yield and greenhouse gas emissions from a banana and a papaya plantation in tropical Australia in the first harvest cycle. Biochar, compost and COMBI organic amendments improved soil properties, including significant increases in soil water content, CEC, K, Ca, NO3, NH4 and soil carbon content. However, increases in soil nutrient content and improvements in physical properties did not translate to improved fruit yield. Counter to our expectations, banana crop yield (weight per bunch) was reduced by 18%, 12% and 24% by B, C and COMBI additions respectively, and no significant effect was observed on the papaya crop yield. Soil efflux of CO2 was elevated by addition of C and COMBI amendments, likely due to an increase in labile carbon for microbial processing. Our data indicate a reduction in N2O flux in treatments containing biochar. The application of B, C and COMBI amendments had a generally positive effect on soil properties, but this did not translate into a crop productivity increase in this study. The benefits to soil nutrient content, soil carbon storage and N2O emission reduction need to be carefully weighed against potentially deleterious effects on crop yield, at least in the short-term.
authors: Centre for Tropical Environmental and Sustainability Science, College of Science, Technology and Engineering, James Cook University, Cairns, Queensland 4870, Australia. Electronic address: adrian.bass@glasgow.ac.uk.
authors: Adrian M
authors: AM
authors: Bass
authors: Centre for Tropical Environmental and Sustainability Science, College of Science, Technology and Engineering, James Cook University, Cairns, Queensland 4870, Australia.
authors: Michael I
authors: MI
authors: Bird
authors: Terrain Natural Resource Management, 2 Stitt Street, Innisfail, Queensland 4860, Australia.
authors: Gavin
authors: G
authors: Kay
authors: Northern Gulf Resource Management Group, 317 Byrnes Street, Mareeba, Queensland 4880, Australia.
authors: Brian
authors: B
authors: Muirhead
mesh_terms: D000383:Agriculture / Q000379:methods*; D000393:Air Pollutants / Q000032:analysis*; D001315:Australia; D002245:Carbon Dioxide / Q000032:analysis; D002606:Charcoal; D004784:Environmental Monitoring; D005308:Fertilizers; D017752:Greenhouse Effect; D009609:Nitrous Oxide / Q000032:analysis; D012987:Soil / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D005308:Fertilizers; D012987:Soil; C540010:biochar; D002245:Carbon Dioxide; D002606:Charcoal; D009609:Nitrous Oxide
keywords: Biochar; Carbon dioxide; Compost; Crop yield; Nitrous oxide; Tropical agriculture