Stabilization of Organic Matter by Biochar Application in Compost-amended Soils with Contrasting pH Values and Textures

Abstract

Food demand and soil sustainability have become urgent concerns because of the impacts of global climate change. In subtropical and tropical regions, practical management that stabilizes and prevents organic fertilizers from rapid decomposition in soils is necessary. This study conducted a short-term (70 days) incubation experiment to assess the effects of biochar application on the decomposition of added bagasse compost in three rural soils with different pH values and textures. Two rice hull biochars, produced through slow pyrolization at 400 °C (RHB-400) and 700 °C (RHB-700), with application rates of 1%, 2%, and 4% (w/w), were separately incorporated into soils with and without compost (1% (w/w) application rate). Experimental results indicated that C mineralization rapidly increased at the beginning in all treatments, particularly in those involving 2% and 4% biochar. The biochar addition increased C mineralization by 7.9%-48% in the compost-amended soils after 70 days incubation while the fractions of mineralized C to applied C significantly decreased. Moreover, the estimated maximum of C mineralization amount in soils treated with both compost and biochar were obviously lower than expectation calculated by a double exponential model (two pool model). Based on the micromorphological observation, added compost was wrapped in the soil aggregates formed after biochar application and then may OPEN ACCESS Sustainability 2015, 7 13318 be protected from decomposing by microbes. Co-application of compost with biochar may be more efficient to stabilize and sequester C than individual application into the studied soils, especially for the biochar produced at high pyrolization temperature.

Biochar and Water Quality

“…Because organic amendments such as biochar, compost, animal manure, and others have different properties, their combination could result in a mix with more diverse and favorable characteristics than a single amendment. For example, biochar can contribute to the stabilization of labile organic C from fresh C source such as compost (Jien et al, 2015). The combination can also prime the positive effects of biochar and address the limitations of biochar for providing nutrients, which may be particularly essential for biochar pyrolyzed at high temperatures (Doan et al, 2015; Jien et al, 2015; Lee et al, 2018).…”

“…For example, biochar can contribute to the stabilization of labile organic C from fresh C source such as compost ( Jien et al, 2015). The combination can also prime the positive effects of biochar and address the limitations of biochar for providing nutrients, which may be particularly essential for biochar pyrolyzed at high temperatures (Doan et al, 2015;Jien et al, 2015;Lee et al, 2018). Some of the mechanisms by which biochar can reduce nitrate leaching are nutrient adsorption and improvement in soil properties .…”

Evaluation of CO2 Emission From Rice Husk Biochar and Cowdung Manure Co-compost Preparation

“…Pyrolysis has been reported to promote the elimination of H and O over C which results in a solid residue (char) with relatively higher C content. A high C:N ratio of biochars has also been reported in other studies (Jien et al, 2015;Spokas, 2010). Generally, a high C:N ratio will reduce the capacity of biochar to release inorganic N when used as a soil amendment (Prommer et al, 2014).…”

Enhancing phosphorus availability, soil organic carbon, maize productivity and farm profitability through biochar and organic–inorganic fertilizers in an irrigated maize agroecosystem under semi‐arid climate

“…Role of biochar has been established in protecting native soil organic matter when co‐applied with other organic amendments such as compost (e.g. Agegnehu et al, 2015; Jien, Wang, Lee & Lee, 2015; Schulz & Glaser, 2012), manures (Lashari et al., 2015) and organic fertilizers (Mau & Utami, 2014). Similar increase in P availability and uptake by maize has been demonstrated after application of biochar and poultry manure together to a calcareous soil (Inal et al., 2015).…”