Combined biochar and nitrogen application stimulates enzyme activity and root plasticity
- authored by
- Xiaona Song, Bahar S. Razavi, Bernard Ludwig, Kazem Zamanian, Huadong Zang, Yakov Kuzyakov, Michaela A. Dippold, Anna Gunina
- Abstract
Biochar (BC) and nitrogen (N) fertilizers are frequently applied to improve soil properties and increase crop productivity. Nonetheless, our mechanistic understanding of plant-soil interactions under single or combined application of BC and N remains incomplete. For the first time, we applied a split-root system to evaluate how BC or N contributes to the changes in soil enzyme activities, N and phosphorus (P) cycling as well as root plasticity. Left and right parts of rhizoboxes were filled with silty-clay loamy soil amended with BC (15 g kg−1 soil, from wheat straw, 300 °C), N (0.05 g KNO3-N kg−1 soil) or a control (no amendments), resulting in the following combinations: BC/Control, N/Control, BC/N. Soil enzyme activities, available N and P, root morphology and plant biomass were analyzed after plant harvest. Plant biomass (shoot + root) ranged from 0.56 g pot−1 (BC/Control) to 0.91 g pot−1(BC/N). The decreased soil bulk density and increased P availability in the BC compartment (BC/Control and BC/N) stimulated root length by 1.4–1.8 times – an effect that was independent of N availability in the same rhizobox. Biochar stimulated activities of β-glucosidase and leucine aminopeptidase (by 33–39%) compared to N due to the coupling of C, N and P cycles in BC/N treated soil. Nitrogen fertilization also increased β-glucosidase activity compared to the unfertilized control, whereas root elongation remained unaffected. Thus, the combined application of BC/N had more efficient benefits for plant growth than BC or N alone. This is linked with i) the stimulation of enzyme activities at the BC locations to reduce N limitation for both microorganisms and plants, and ii) an increase of fine root production to improve N uptake efficiency. Thus, combined BC/N application is potentially especially sustainable to overcome nutrient limitation as well as to maintain crop productivity because it accelerates root-microbial interactions.
- External Organisation(s)
-
University of Göttingen
University of Kassel
China Agricultural University
Kiel University
Peoples' Friendship University of Russia (RUDN)
- Type
- Article
- Journal
- Science of the Total Environment
- Volume
- 735
- ISSN
- 0048-9697
- Publication date
- 15.09.2020
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Environmental Engineering, Environmental Chemistry, Waste Management and Disposal, Pollution
- Sustainable Development Goals
- SDG 2 - Zero Hunger
- Electronic version(s)
-
https://doi.org/10.1016/j.scitotenv.2020.139393 (Access:
Closed)
