From crop left-overs to nutrient resource: growth-stimulating potential of biochar in nutrient solutions for wheat soilless cultivation systems

Kris Kunnen; Md Muntasir Ali; Amine Lataf; May Van Hees; Robin Nauts; Nele Horemans; Dries Vandamme; Ann Cuypers

doi:10.3389/fpls.2024.1414212

From crop left-overs to nutrient resource: growth-stimulating potential of biochar in nutrient solutions for wheat soilless cultivation systems

Front Plant Sci. 2024 Sep 5:15:1414212. doi: 10.3389/fpls.2024.1414212. eCollection 2024.

Authors

Kris Kunnen¹, Md Muntasir Ali², Amine Lataf³, May Van Hees², Robin Nauts², Nele Horemans^{1

2}, Dries Vandamme³, Ann Cuypers¹

Affiliations

¹ Environmental Biology, Centre for Environmental Sciences (CMK), Hasselt University, Diepenbeek, Belgium.
² Biosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium.
³ Analytical and Circular Chemistry, Institute for Materials Research (imo-imomec), Hasselt University, Diepenbeek, Belgium.

Abstract

To reach the estimated food demands for 2050 in decreasingly suiting climates, current agricultural techniques have to be complemented by sustainably intensified practices. The current study repurposed wheat crop residues into biochar, and investigated its potential in different plant cultivation systems, including a hydroponic cultivation of wheat. Biochars resulting from varying pyrolysis parameters including feedstock composition (straw and chaff) and temperature (450°C and 600°C), were tested using a fast plant screening method. Biochar WBC450, produced from a combination of chaff and straw at 450°C, was selected for further plant experiments, and used in a static leaching experiment in the Arabidopsis thaliana cultivation medium. Increased pH and EC were observed, together with an increase of most macronutrient (K, Mg, P, S) and a decrease of most micronutrient (Fe, Mn, Zn) concentrations. Considering plant growth, application of biochar resulted in concentration-dependent effects in both tested plant species (A. thaliana and wheat). It improved the vegetative yield across all tested cultivation systems. Increases in K and S, and concentration-dependent decreases in Fe and Na content in wheatgrass were observed. Biochar influenced the reproduction of hydroponically cultivated wheat by increasing the number of spikes and the number of seeds per spike. The antioxidative capacity of wheat grass, and the seed sugar and starch contents remained unaffected by biochar application. This study contributes to innovation in soilless cultivation approaches of staple crops, within the framework of closing waste loops for a circular bioeconomy.

Keywords: Arabidopsis thaliana; biochar; circular bioeconomy; hydroponics and soilless culture; plant growth; wheat.

Grants and funding

The author(s) declare financial support was received for the research, authorship and/or publication of this article. The authors declare that this study received funding from Flanders’ FOOD and Flanders Innovation and Entrepreneurship (VLAIO) as part of the SpaceBakery project (grant number HBC.2019.0100). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.