The influence of biochar on soil characteristics in a temperate agroecosystem

While biochar as a soil amendment is not a novel concept, the addition of biochar to temperate agricultural soils represents a relatively new territory. The objectives of this study were to evaluate soil characteristics in a conventional temperate agricultural production system amended with biochar under a maize (Zea mays) crop in southern Ontario, Canada. The treatments include: poultry manure (6 t/ha) and nitrogen fertilizer (135 kg/ha) (MN); manure (3t/ha) and biochar (3t/ha) (MB); and manure (3 t/ha), fertilizer (urea) (135 kg/ha) and biochar (3 t/ha) (MNB). Please click on the file below for full content of the abstract

Evaluation of the long-term effects of pre-conditioned biochar on soil organic carbon in temperate soils using the Century Soil Organic Matter model

Biochar contains a limited quantity of available mineral nutrients, requiring its addition in large quantities, in temperate soils, and in association with nitrogen (N) fertilizer and/or manure. Alternatively, biochar could be pre-conditioned with urea ammonium nitrate (UAN-enriched biochar), requiring lower inputs of biochar. The objective of this study was to evaluate the long-term (150 years) impact of the addition of UAN-enriched biochar on soil organic carbon (SOC), and soil active, slow and passive carbon (C) fractions compared to other commonly used agroecosystem management practices in a coarse and medium textured soil using the Century Soil Organic Matter Model. Please click on the file below for full content of the abstract

Behavioral factors affecting the adoption of biochar of farmers in Canada

Biochar is a promising carbon-based soil amendment with ancient, South American roots. Despite its long history, research surrounding its use in modern agriculture has only just begun in North America. There are several studies examining biochar in soil, ranging from its effects on nutrient and water retention to the way it affects earthworms and other organisms. However, our understanding on the socioeconomic implications of using biochar as a soil amendment in temperate agriculture remains scarce. Our research aims to fill this gap through semi-structured interviews with farmers and the completion of an economic analysis based on market values of biochar feedstocks and the current projected findings of biochar’s influence on crop yields. Please click on the file below for full content of the abstract

Effect of biochar addition on carbon dioxide and nitrous oxide emissions from a temperate agricultural soil

Amending intensively managed temperate soils with biochar is a more recent approach to agriculture, with research is still in its infancy. A knowledge gap remains on the effect of biochar on greenhouse gas (GHG) emissions, as most studies conducted to date were short-term (\u3c4 months) in the field or used laboratory incubations; neither of which capture temporal variations in emissions. Therefore the objective of this study was to evaluate soil CO2 and N2O emissions in a conventional agricultural production system amended with biochar and under a maize (Zea mays) crop in southern Ontario, Canada. Please click on the file below for full content of the abstract

Predicting changes in soil organic carbon after a low dosage and one-time addition of biochar blended with manure and nitrogen fertilizer

Modeling plays an important role in predicting the long-term effects of biochar on soil organic carbon dynamics. The objective of our study was to apply the Century model to assess changes in temporal soil organic carbon in soil amended with manure and nitrogen fertilizer (MN), with manure and biochar (MB) or with manure, nitrogen fertilizer and biochar (MNB). We determined that, after 115 years, soil organic carbon stocks could not reach a steady state (equilibrium) or pre-cultivation levels, regardless of amendment type. Our results showed that a biennial input of manure and nitrogen fertilizer (MN) led to a 84% increase in soil organic carbon compared to a 79% (MNB) and 70% (MB) increase when amendments contained biochar. However, the quantity of organic matter input from crop residues and amendments was sufficient to increase the active fraction, with a turnover time of months to years, by 86%. In fact, carbon associated with the slow fraction, with a turnover time of 20 to 50 years, was the key driver for soil organic carbon accumulation in all amendment types. Although the passive fraction is the most stable form of carbon in the soil, with a turnover time of 400 to 100 years, once manure and biochar were added to the soil, this fraction increased up to 32%. Our results provided further insight into the ability of Century to accurately predict changes in soil organic carbon stocks when a combination of manure, nitrogen fertilizer or biochar were added to soil. Century predicted soil organic carbon stocks within -1% to +9% of measured values. However, further fine-tuning of the model is required since biochar undergoes chemical transformations (e.g., ageing) and changes soil physical parameters (e.g., bulk density) that can not be currently accounted for in the Century model. Addressing these limitations of Century will also help to increase the relationship between measured and predicted values

Expansion of Agriculture in Northern Cold-Climate Regions: A Cross-Sectoral Perspective on Opportunities and Challenges

Agriculture in the boreal and Arctic regions is perceived as marginal, low intensity and inadequate to satisfy the needs of local communities, but another perspective is that northern agriculture has untapped potential to increase the local supply of food and even contribute to the global food system. Policies across northern jurisdictions target the expansion and intensification of agriculture, contextualized for the diverse social settings and market foci in the north. However, the rapid pace of climate change means that traditional methods of adapting cropping systems and developing infrastructure and regulations for this region cannot keep up with climate change impacts. Moreover, the anticipated conversion of northern cold-climate natural lands to agriculture risks a loss of up to 76% of the carbon stored in vegetation and soils, leading to further environmental impacts. The sustainable development of northern agriculture requires local solutions supported by locally relevant policies. There is an obvious need for the rapid development of a transdisciplinary, cross-jurisdictional, long-term knowledge development, and dissemination program to best serve food needs and an agricultural economy in the boreal and Arctic regions while minimizing the risks to global climate, northern ecosystems and communities