Short‐term biochar effects on greenhouse gas emissions and phosphorus availability for maize

Abstract

Due to environmental issues, many methods of exploiting renewable natural resources are alternatives to reduce the dependence on non‐renewable agricultural inputs. Phosphate fertilization on weathered tropical soil and waste reuse, for example, requires better management strategies. Thus, biochar from organic residues can be a strategy to reduce pressure on natural resources, in addition to having the potential to mitigate climate change. This study aimed to evaluate the availability of P in tropical soils from the interaction of biochar and arbuscular mycorrhizal fungi (AMF) in the aboveground and root systems of the plant and its impact on greenhouse gas (GHG) emissions. The results indicated that the addition of biochar was an alternative for C sequestration and GHG mitigation, causing no damage to the plant. The applied biochar amount had, for the most part, emission equal to or less than the control treatment (soil only). The sugarcane straw biochar (BCS) showed higher emissions, mainly in the presence of P and AMF. Biologically speaking, there was no significant effect in the presence of mycorrhizae. However, with regard to plant production, treatments where mycorrhizae were inoculated, longer and wider leaves were found. In the production of maize (Zea mays L.) plant material (aboveground and root), the upper and lower values were related to the poultry manure biochar (BPM) , and the presence of P, the values were lower, indicating that, for the good development of the plant, only the presence of the biochar is sufficient, without requiring the addition of phosphate fertilizer.

Revamping highly weathered soils in the tropics with biochar application: What we know and what is needed

“…Biochar has a negative GHG emission potential owing to (a) reduced biomass decay due to stabilization of OM (Zimmerman and Gao, 2013;Singh and Cowie, 2014), (b) indirect net effects including lowered CH4 and N2O emissions (Van Zwieten et al, 2015;Sun et al, 2021), and (c) enhanced plant productivity (Novak et al, 2010). Diverse mechanisms of GHG formation in various soil types and heterogeneous interactions between biochar and GHG evolving/consuming microorganisms in the soil could result in a mixed effect of biochar on net GHG emission from a biochar-treated soil under identical climatic and environmental conditions (Amoakwah et al, 2020;Zenero et al, 2021). The GHG emission issue is more pronounced in weathered tropical soils than temperate soils due to low pH and poor nutrient use efficiency, particularly nitrogenous fertilizer (Jeffery et al, 2017).…”

“…Field experimental results from Columbian and Kenyan weathered soils showed about 80% suppression of N2O emission and considerable reduction of CH4 emission, respectively, due to biochar addition (Renner, 2007). Overall, biochar could play a dual role by reducing GHG emission and simultaneously enhancing soil C sequestration (Zenero et al, 2021), which warrant field scale studies in the future.…”