Assessing the environmental benefit of a new fertilizer based on activated biochar applied to cereal crops

Abstract

This study analyzes the environmental benefits that a nitrogen fertilizer based on activated biochar has in comparison to other traditional fertilizers (urea, ammonium nitrate (AN), ammonium sulfate (AS) and di-ammonium phosphate (DAP)). With this aim, activated biochar was generated from residual biomass (barley straw) through physical activation and the resulting biochar was combined with mineral fertilizer to synthethise the fertilizer. This new product was subjected to environmental assessment by means of two different approaches, Life Cycle Assessment (LCA) and nitrogen footprint procedure, both of which considered standard conditions typical of Mediterranean climate and wheat and corn as the fertilized crops. Emission factors of traditional fertilizers were obtained from internally developed models, which were in turn based on real data from literature. As for emission factors of the new product, they were calculated basing on experimental results. Fertilizer impacts in terms of acidification, eutrophication and climate change were estimated, thus revealing a great performance of activated biochar over other fertilizers in terms of reactive nitrogen (Nr), reaching a maximum saving rate of 63% in the amount of Nr released by volatilization and leaching. In addition, this work offers a methodology *Manuscript (double-spaced and continuously LINE and PAGE numbered)-for final publication Click here to view linked References for environmental analysis of fertilizers and provides useful quantitative indicators for the environmental benefit and the saving of reactive nitrogen, which could contribute to the development of new commercial low N-emissions fertilizers.

Nitrogen Use Efficiency and Crop Yield in Four Successive Crops Following Application of Biochar and Zeolites

“…Also in this area, it is possible to find results showing a reduction in emissions (Singh et al 2010;Spokas et al 2012), an increase (Chen et al 2015;Agegnehu et al 2016), or where emissions have depended on the conditions of the biochar application (Wei et al 2020). Studies evaluating the dynamic of inorganic N in the soil, and the risk of nitrate leaching, tend to show more coincident results, with lower values of inorganic N in the soil after the application of biochar (Sun et al 2017;Li et al 2019;González-Cencerrado et al 2020). Currently, there seems to be no doubt about the effects of biochar on the dynamics of N in the soil.…”

A critical review of biochar-based nitrogen fertilizers and their effects on crop production and the environment

“…Wang et al (2015) also observed that NO 3 − leaching loss was the predominant pathway of N loss and contributed to 52-96% of total N leached from BBNFs. But compared with urea and NH 4 NO 3 , NO 3 − leaching loss was reduced by over 60% with BBNFs (González-Cencerrado et al 2020). Jia et al (2021) reported that the cumulative leaching loss of NO 3 − with BBNFs was 25% lower than urea.…”

“…While biochar amendment to soil can reduce N loss from leaching (Yoo et al 2014;Hossain et al 2020), volatilization (Nguyen et al 2017), or denitrification (Cayuela et al 2015). Leaching is a primary loss pathway for N (González-Cencerrado et al 2020). Among all the solid nitrogenous fertilizers, urea contains the highest N content of 46% and is therefore widely used.…”

“…Biochar can also be activated to increase its surface area or surface functional groups. In the preparation of a BBNF product, barley straw-based biochar was physically activated using CO 2 and then mixed with N, P, K and micro-nutrients resulting in lower N losses from a sandy clay loam soil (by up to 63%) compared to either urea or NH 4 NO 3 (González-Cencerrado et al 2020).…”

Nitrate Ion Adsorption Characteristics of Activated Carbon Fibers with and without Quaternary Nitrogen Effective for Anion Adsorption

“…It has been shown that ingestion of drinking water containing nitrate/nitrite (10 mg-NO 3 − /L) increased the concentration of nitroso compounds in urine. 4,5) High concentrations of nitrate/ nitrite in drinking water can cause harmful effect on human health. Nitrate/nitrite also causes eutrophication in lakes and reservoirs, 6) resulting in environmental pollution such as algal blooms.…”