Does biochar improve all soil ecosystem services?

Abstract

Biochar is considered to sequester C and deliver other soil ecosystem services, but an overview that synthesizes the current knowledge of biochar implications on all essential soil ecosystem services is difficult to find in the ample biochar literature. Most previous research and review articles on this topic focused on a single ecosystem service and did not integrate all essential soil ecosystem services. This overview paper (1) synthesizes the impacts of biochar on water and wind erosion, C sequestration, soil water, nutrient leaching, soil fertility, crop yields, and other soil ecosystem services based on published literature and (2) highlights remaining research areas. Literature indicates that, in addition to sequestering C, biochar can reduce N2O emissions, nitrate leaching, and runoff; increase soil microbial biomass, plant available water, and crop yields (particularly in tropical regions), and CO2 emissions; and have small or no effects on water and wind erosion. Biochar benefits can be in this order: C sequestration > N2O emissions > Nitrate leaching > Available water > Soil biology > Soil fertility > Crop yields > Runoff. However, literature also indicates that biochar does not always improve all ecosystem services. Its benefits depend on biochar feedstock, pyrolysis temperature, application rate, biochar properties, soil properties, climate, and other factors. For example, biochar can enhance crop yields more in degraded and low fertility soils than in highly fertile and fine‐textured soils. Long‐term (>3 years) field‐scale studies under different soil types, management conditions, and climates are needed for a determination of optimum levels of application, comprehensive life‐cycle analysis, and assessment of agronomic and environmental tradeoffs. Overall, biochar can improve most soil ecosystem services, but the extent of such improvement is highly dependent on biochar properties and soil and climatic conditions.

Assessment of Water Hyacinth Biochar as a Soil Amendment for Sandy Soils

“…In general, biochar nowadays is considered for carbon sequestration and delivering different soil ecosystem services (Blanco-Canqui, 2021). Biochar is a porous carbonaceous solid material having a relatively high degree of aromatization and strong anti-decomposition ability (Blanco-Canqui, 2021;Bottezini et al, 2021).…”

“…In general, biochar nowadays is considered for carbon sequestration and delivering different soil ecosystem services (Blanco-Canqui, 2021). Biochar is a porous carbonaceous solid material having a relatively high degree of aromatization and strong anti-decomposition ability (Blanco-Canqui, 2021;Bottezini et al, 2021). Biochar is generated by pyrolysis of plant biomass or animal wastes at elevated temperatures (350 °C to 1000 °C), under a limited supply of oxygen (Wu et al 2017;Ahmed et al 2018).…”

“…Biochar is generated by pyrolysis of plant biomass or animal wastes at elevated temperatures (350 °C to 1000 °C), under a limited supply of oxygen (Wu et al 2017;Ahmed et al 2018). Biochar is one of the stable forms of carbon and it is rapidly gaining popularity in the last few decades due to the improvement in agricultural productivity, environmental remediation and for carbon sequestration (Das et al, 2016;Blanco-Canqui, 2021). Biochar exhibits a great potential in maintaining soil fertility, deactivating pesticides over abiotic degradation and accelerating pesticide biodegradation (Ding et al, 2017).…”

Biochar in temperate soils: opportunities and challenges

“…Despite biochar can persist in the soil for thousands of years, and the impact of biochar on soil chemical, physical and biological properties may be a critical factor in the plant-soil system continuum, limited information on biochar aging is available (Hardy et al, 2019;Blanco-Canqui et al 2020;Wang et al 2020;Kalu et al 2021). Additionally, a limited number of long-term field studies examined the effect of biochar on crop productivity on fertile temperate agricultural soils, and most of this research was conducted under controlled laboratory or greenhouse conditions (Boersma et al 2017).…”

“…Although the effect of biochar addition to tropical and temperate soils has varying outcomes, it is suggested that the management approach between the two biomes should be different (Liu et al 2013). Blanco-Canqui (2020) synthesized which ecosystem services are or are not positively impacted by biochar amendment.…”