Biochar addition to organo-mineral fertilisers delays nutrient leaching and enhances barley nutrient content

ABSTRACT

Biochar, a carbon-rich solid produced from biomass pyrolysis, has attracted growing interest as a fertiliser ingredient due to its ability to non-permanently retain nutrients. A greenhouse pot experiment was set up to compare three commercial organo-mineral fertiliser formulations (NPK, NP and K) with the corresponding formulations containing a slow-pyrolysis wood biochar (NPK+B, NP+B and K+B) (6 replications each). Nutrient leaching as well as crop growth and nutrient uptake was monitored using barley as model species. Nutrient leaching was slowed down in the NPK+B compared to the NPK fertiliser. The most responsive ions were nitrate and potassium, whose leaching during the two first weeks was reduced by 28% and 22%, respectively, while this trend reversed from the third week on. One plausible explanation would be a microbial nutrient immobilisation mediated by the concurrent NPK and biochar habitat provision. NPK+B significantly enhanced barley straw biomass (23.43% increase respect to NPK), whereas all the biochar-based fertilisers showed increases in nutrient content and export (involving potassium, sulphur, calcium and manganese), possibly indicating that biochar acted as a nutrient source. These results provide some evidence of the potential use of the studied biochar in biochar-based fertilisers to meet nutrient availability with plant demands.

KEYWORDS:

• Biochar-based fertilisers
• nutrient leaching
• barley
• crop growth
• nutrient content

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data will be available upon request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03650340.2022.2161092

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was funded by the project FERTICHAR (AGL2015-70393-R) of the Spanish Ministry of Economy and Competitiveness and is supported by a Margarita Salas grant under the European Union-NextGenerationEU funds.