Biochar for sustainable soil management

Self Cite

The 26th annual summit of the United Nations climate change conference (COP26) was held in Glasgow, UK, between 31 October and 13 November 2021. The summit achieved significant progress towards stronger and more concerted international efforts in combating climate change. Among others, the second most important greenhouse gas, methane, stepped into the centre of the stage. Over 100 countries have joined the Global Methane Pledge, committing to reduce methane emissions by at least 30% from 2020 to 2030 (EU, 2021). China and the United States agreed to enhance their collaboration on climate action in the 2020s by giving an unexpected joint declaration (USDOS, 2021). Moreover, the international community has for the first time agreed to reduce coal, the worst fossil fuel, accounting for the largest amount of CO 2 emissions, and developed countries are agreeing to help developing countries on adaptation efforts (Rincon, 2021). These advances are encouraging for the international community, especially after years of split and setback after the 2015 Paris agreement during COP21 with, for example, the withdrawal from the Paris agreement by the Trump administration (McGrath, 2020).

Section: Carbon Sequestration With Sustainable Soil Managementmentioning

confidence: 99%

Expediting climate‐smart soils management

Hou

2021

Self Cite

“…Biochar has attracted much attention as a soil amendment with the potential to benefit carbon sequestration, soil remediation and increase crop production (Carneiro et al, 2021; Hou, 2021; Shi et al, 2021). Biochar is a carbon‐rich compound formed by the controlled pyrolysis of agricultural waste and other biomass (Simmons et al, 2021; Vochozka et al, 2016) and has the advantages of large specific surface area, developed pore structure, and strong ion absorption and exchange capacity (Cao et al, 2017; Gong et al, 2019; Hu et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Effects of biochar nanoparticles as a soil amendment on the structure and hydraulic characteristics of a sandy loam soil

Chen

Duan

Zhou

et al. 2021

Biochar as a soil amendment can influence the physical and solute transport properties of soils and, thus, provide a means to improve soil fertility. However, the use of different sized biochar particles down to the nano‐scale has revealed inconsistent results, with the mechanisms poorly understood owing to a lack of experimental data. This study investigated the effects and mechanisms of nano‐sized biochar particles (NBC) applied to a sandy loam soil with regard to impacts on the hydraulic characteristics and soil structure. Column experiments were carried out with NBC application rates of 0.0%, 0.3%, 0.5%, 0.7% and 1.0% (by weight). It was found that the NBC changed the distribution of the soil pore structure and affected the degrees of anisotropy, fractal dimension, soil porosity and stability of soil aggregates. NBC applications also increased the water repellency of the soil and reduced the surface energy of soil particles. Regarding soil hydraulic properties, NBC applications increased the saturated hydraulic conductivity of the soil and decreased soil water retention. Increasing the amount of NBC applied to the mixing‐layer decreased cumulative infiltration values (reduced by 3.75%–13.75%). The above results reveal how NBC affects the soil pore structure and soil hydraulic characteristics, which provides a theoretical basis for the systematic evaluation of soil improvement and environmental effects of nano‐sized biochar.

“…Uncontrolled nitrogen fertilization can also severely degrade soil quality (Sainju et al, 2019; Raza et al, 2020), and nitrogen use efficiency (NUE) has been declining over the past decades (Swaney et al, 2018). These problems require diligent efforts to develop sustainable practices, with organic amendments, including biochar and manure, that offer good potential (Hou, 2021).…”

Section: Introductionmentioning

confidence: 99%

No significant influence of biochar and manure application on nitrogen fate and sequestration by tomato and garlic crops: A field experiment in California, USA

Gao

Duan

Wang

et al. 2021

Organic soil amendments can improve soil health but their role in improving N management has not been well quantified. The objectives of this research were to evaluate the influence of biochar and manure compost application on crop yield, N uptake, changes in soil and environmental losses and to use the information to assess the N requirement and project fertilization needs. A field experiment was conducted in California, USA, with processing tomato (Lycopersicon esculentum Mill.) grown first, followed by garlic (Allium sativum). The soil was a sandy loam with a pH of 7.2 and CEC of 9.1 cmol(+) kg−1. Treatments included two biochar products, derived from almond shell or softwood feedstocks, applied at 20 or 40 tonnes (t) ha−1, dairy manure compost at 20 t ha−1, combinations of the manure and the biochar (each at 20 t ha−1), and a control. Although biochar and manure applications improved the surface soil organic C and total N content, no significant effects on crop yield, biomass and N uptake, as well as ammonia volatilization and leaching loss, were observed. The amount of N sequestered by plants ranged from 3.2 to 3.8 and 9.9 to 10.0 kg N Mg−1 to produce fresh tomato fruits and garlic bulbs, respectively. However, about half of the N for tomato and 93% for garlic plants were removed from soil by harvesting. The N sequestered per unit biomass (or yield) production appears a stable parameter, which can be used to reliably project fertilization needs that target high NUE and minimal loss to the environment.