Nitrogen speciation and transformations in fire-derived organic matter

Torres-Rojas, Dorisel; Hestrin, Rachel; Solomon, Daniel; Gillespie, Adam; Dynes, James J.; Regier, Tom; Lehmann, Johannes

doi:10.1016/j.gca.2020.02.034

Cited by 27 publications

(30 citation statements)

References 88 publications

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“…Li et al (2020) noted a negative effect of high biochar rates (>50 Mg ha −1 ) on microbial diversity, and suggested the following potential causes: (i) introduction of toxic components that inhibit some species; (ii) increase in the C:N ratios of SOM that limits microbial C utilization, possibly only in the short term and only to the extent that the organic C is metabolized; and (iii) disruption of microbial microenvironments. Note also that C:N ratio does not influence microbial metabolization of biochars (Torres‐Rojas et al, 2020).…”

Section: Mechanisms Of Biochar Effects On Soil and Plantsmentioning

confidence: 99%

“…Much of the N within the biochar C matrix (e.g., heterocyclic‐N) is unavailable to plants (Clough et al, 2013; Torres‐Rojas et al, 2020), whereas most K in biochar is present in soluble forms, released in the short term after application to soil (Silber et al, 2010), and is readily available to plants. Meta‐analyses have found that biochar application commonly increases P availability, particularly when applied to acidic or neutral soils, and for biochar produced from low C:N feedstocks (e.g., manure, crop residues), and produced at low temperatures (Gao et al, 2019; Glaser & Lehr, 2019).…”

Section: Mechanisms Of Biochar Effects On Soil and Plantsmentioning

confidence: 99%

“…Meta‐analyses have found that biochar application commonly increases P availability, particularly when applied to acidic or neutral soils, and for biochar produced from low C:N feedstocks (e.g., manure, crop residues), and produced at low temperatures (Gao et al, 2019; Glaser & Lehr, 2019). However, P availability can be low in Ca‐rich and K‐poor feedstocks such as sewage sludge (Buss et al, 2018, 2020; Torres‐Rojas et al, 2020; Wang et al, 2019) because pyrolysis can convert plant‐available organic P into inorganic P that is less available in the short term (Buss et al, 2020; Rose et al, 2019). The opposite has also been observed, with pyrolysis increasing plant‐available P although decreasing water‐extractable P (Wang et al, 2014; Zwetsloot et al, 2015, 2016).…”

Section: Mechanisms Of Biochar Effects On Soil and Plantsmentioning

confidence: 99%

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How biochar works, and when it doesn't: A review of mechanisms controlling soil and plant responses to biochar

et al. 2021

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We synthesized 20 years of research to explain the interrelated processes that determine soil and plant responses to biochar. The properties of biochar and its effects within agricultural ecosystems largely depend on feedstock and pyrolysis conditions. We describe three stages of reactions of biochar in soil: dissolution (1–3 weeks); reactive surface development (1–6 months); and aging (beyond 6 months). As biochar ages, it is incorporated into soil aggregates, protecting the biochar carbon and promoting the stabilization of rhizodeposits and microbial products. Biochar carbon persists in soil for hundreds to thousands of years. By increasing pH, porosity, and water availability, biochars can create favorable conditions for root development and microbial functions. Biochars can catalyze biotic and abiotic reactions, particularly in the rhizosphere, that increase nutrient supply and uptake by plants, reduce phytotoxins, stimulate plant development, and increase resilience to disease and environmental stressors. Meta‐analyses found that, on average, biochars increase P availability by a factor of 4.6; decrease plant tissue concentration of heavy metals by 17%–39%; build soil organic carbon through negative priming by 3.8% (range −21% to +20%); and reduce non‐CO2 greenhouse gas emissions from soil by 12%–50%. Meta‐analyses show average crop yield increases of 10%–42% with biochar addition, with greatest increases in low‐nutrient P‐sorbing acidic soils (common in the tropics), and in sandy soils in drylands due to increase in nutrient retention and water holding capacity. Studies report a wide range of plant responses to biochars due to the diversity of biochars and contexts in which biochars have been applied. Crop yields increase strongly if site‐specific soil constraints and nutrient and water limitations are mitigated by appropriate biochar formulations. Biochars can be tailored to address site constraints through feedstock selection, by modifying pyrolysis conditions, through pre‐ or post‐production treatments, or co‐application with organic or mineral fertilizers. We demonstrate how, when used wisely, biochar mitigates climate change and supports food security and the circular economy.

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Section: Mechanisms Of Biochar Effects On Soil and Plantsmentioning

confidence: 99%

Section: Mechanisms Of Biochar Effects On Soil and Plantsmentioning

confidence: 99%

Section: Mechanisms Of Biochar Effects On Soil and Plantsmentioning

confidence: 99%

See 1 more Smart Citation

How biochar works, and when it doesn't: A review of mechanisms controlling soil and plant responses to biochar

et al. 2021

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“…The correlation between dichloroacetic acid (DCAA) yield and SUVA 254 for NED was improved by removing an outlier (DCAA yield = 199 μg DBP /mg DOC ) from the model acids (Thurman et al, 2020). Nitrogen enrichment of DOM at moderate temperatures has been observed by Cawley et al; however, nitrogen enrichment of thermally altered DOM could also dually be a function of heating temperature and the initial nitrogen content of the DOM (Cawley et al, 2017;Torres-Rojas et al, 2020). Finally, physical alterations to the mineral horizon could also partially explain increased DOC and DON solubility (Jian et al, 2018).…”

Section: Discussionmentioning

confidence: 99%

Impact of simulated wildfire on disinfection byproduct formation potential

Wilkerson

Rosario‐Ortiz

2021

AWWA Water Science

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Wildfires are complex phenomena that have served a vital role in ecosystem function for millennia. However, thermal alterations to dissolved organic matter's (DOM) solubility and chemical features can change disinfection byproduct (DBP) formation dynamics. Physicochemical changes to DOM are influenced by several factors, the most prominent being heating temperature. In this study, mineral soil samples were collected from fire-prone areas, artificially heated in a muffle furnace to simulate wildfire heating, and leached. As heating temperature increased, chloroform and dichloroacetic acid yields decreased and increased, respectively. Of particular interest was the stimulation of dichloroacetonitrile, a highly toxic and unregulated DBP, at moderate heating temperatures. To demonstrate further insight into the chemical attributes of wildfire-impacted DOM, optical properties were used as proxy measurements. This work provides water utilities with information on how wildfires can alter DBP formation potential, and a means to investigate correlations between intrinsic optical measurements and DBP yields.

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“…Loss of NH 3 –N was calculated as a portion of N present in the initial poultry manure and straw mixture, excluding the quantity of N introduced through biochar additions. Because the quantity of both unoxidized and oxidized biochar added to the compost contained less than 2% of the N present in the poultry manure and straw and because typical mineralization rates of N in woody biochar are very low due to its persistent nature (Torres‐Rojas et al., 2020), biochar‐N was excluded from the denominator in calculations of NH 3 –N loss per unit of initial compost N. If biochar‐N did contribute to NH 3 –N loss, then calculated losses of compost feedstock N presented in this manuscript could be up to 2% lower than the values reported per unit of initial compost N. Loss of CO 2 –C was also calculated as a proportion of C present in the poultry manure and straw, excluding the quantity of C introduced through biochar additions. Similar to biochar‐N, it is likely that a relatively low proportion of biochar‐C was mineralized during composting, and the same error estimate applies.…”

Section: Methodsmentioning

confidence: 99%