Enhanced growth of halophyte plants in biochar‐amended coastal soil: roles of nutrient availability and rhizosphere microbial modulation

Abstract

Soil health is essential and irreplaceable for plant growth and global food production, which has been threatened by climate change and soil degradation. Degraded coastal soils are urgently required to reclaim using new sustainable technologies. Interest in applying biochar to improve soil health and promote crop yield has rapidly increased because of its multiple benefits. However, effects of biochar addition on the saline-sodic coastal soil health and halophyte growth were poorly understood. Response of two halophytes, Sesbania (Sesbania cannabina) and Seashore mallow (Kosteletzkya virginica), to the individual or co-application of biochar and inorganic fertilizer into a coastal soil was investigated using a 52 d pot experiment. The biochar alone or co-application stimulated the plant growth (germination, root development, and biomass), primarily attributed to the enhanced nutrient availability from the biochar-improved soil health. Additionally, the promoted microbial activities and bacterial community shift towards the beneficial taxa (e.g. Pseudomonas and Bacillus) in the rhizosphere also contributed to the enhanced plant growth and biomass. Our findings showed the promising significance because biochar added at an optimal level (≤5%) could be a feasible option to reclaim the degraded coastal soil, enhance plant growth and production, and increase soil health and food security.

Reclamation of Saline–Sodic Soils with Combined Amendments: Impact on Quinoa Performance and Biological Soil Quality

“…These results are consistent with our hypothesis that B and HS enhance soil microbial activity. Zheng et al [24] noticed that B (peanut Shell 350 • C) induced a microbial response in the rhizosphere. Moreover, Bhaduri et al [61] also reported that B application (peanut Shell 300 • C, in 5% dose) on saline soil influenced microbial growth and C use efficiency led to increases in soil microbial biomass.…”

Biochar applications decrease reproductive potential of the English grain aphid Sitobion avenae and upregulate defense‐related gene expression

“…In addition to silicon content, rhizosphere microorganisms may be enhanced by biochar amendment to soils to increase induced defense responses. Many studies indicate that biochar amendment to soils can change the composition of microbial communities in the rhizosphere . In addition, biochar contains a number of organic compounds belonging to various chemical classes, some of which may directly elicit plant defense responses .…”

Simultaneous measurement of bacterial abundance and composition in response to biochar in soybean field soil using 16S rRNA gene sequencing

“…We observed that the overall abundances of Actinobacteria , Elusimicrobia , Planctomycetes , Verrucomicrobia , and WCHB1_60 phyla were significantly higher in the rhizosphere with the biochar treatments, whereas only Elusimicrobia was selected at the phylum level in the bulk soils (Figure ). Greater abundance of specific bacterial species (i.e., Proteobacteria , Bacteroidetes , Acidobacteria , and Verrucomicrobia ) was also found in the biochar‐amended rhizosphere soil than those without biochar (Zheng et al, ). Secondly, the responding microbes in the rhizosphere soil were outnumbered than those in the bulk soil, despite the level of taxonomic resolution and number of microbial domains (Figures and ; Table ), indicating that the effects of biochar addition on rhizosphere bacterial community were more evident than those on bulk soil.…”