Evaluation aging of biochar application to deficient N soils on their N cycling using 15N isotope tracer, plant growth and soil biochemical parameters

Soil degradation caused by climate change leads to unfavorable conditions for soil and crop growth in many countries. Therefore, the use of soil organic amendments (OSAs) are promoted for crop growth and increase fertility in soils. A popular soil organic amendment is biochar which is known for being a good strategy for agriculture to increase sustainability and health of soils. Although great effort is conducted to reveal the combined effect  of different biochar application forms to soils on the chemical composition of soil organic matter and plant growth, there is still a lack of understanding in terms of how those practices affect the N cycling and associated biochemical processes. Therefore, in this work we aim to characterize the fate of nitrogen added to soils amended with fresh, aged, and co-composted biochar and cultivated with  Lactuca sativa L. var. Therefore ¹⁵N-enriched fertilizer was used and the partitioning of the  ¹⁵N isotope between soil, root and shoot of lettuce plants was measured and related to soil properties, soil organic matter composition, microbial respiration and plant growth. This study explores the multiple positive and negative interactions between different types of biochar addition as soils organic amendments and plant physiological traits. Thus, through soil organic amendments not only greater crop performance can be achieved but also it is key to build knowledge on the relations among soil chemical composition and plant growth to optimize health in European soils.

Acknowledgements: Funded by the European Union. Grant agreement No. 101059546, María Rocio Reinoso, Laura Gismero Rodríguez and Andreas Lücke are thanked for their technical help in the laboratory.