Abstract
The application of biochar stimulates the activities of microorganisms that affect soil quality and plant growth. However, studies on the impacts of biochar mainly focus on a monoculture, its effects on interspecific interactions are rarely reported. Here, we investigated the impacts of biochar on tomato/potato–onion intercropped (TO) in a pot experiment. Tomato monoculture (T) and TO were treated with no, 0.3, 0.6, and 1.2% biochar concentrations in a pot experiment. Microbial communities from tomato rhizosphere soil were analyzed by quantitative PCR and Illumina MiSeq. The results showed that compared with the tomato monoculture, 0.6%TO and 1.2%TO significantly increased tomato yield in 2018. TO and 1.2%TO significantly increased plant height and dry weight in 2018 and 2019. Biochar treatments increased soil pH, decreased NO-N and bulk density, and increased the absorption of N, P, and K by tomato. Bacterial and fungal abundances increased with an increase in biochar concentration, while Bacillus spp. and Pseudomonas spp. abundances showed an “increase-decrease-increase” trend. Biochar had a little effect on bacterial diversities but significantly lowered fungal diversities. TO, 0.6%TO, and 1.2%TO increased the potentially beneficial organisms (e.g., Pseudeurotium and Solirubrobacter) and lowered the potentially pathogenic organisms (e.g., Kribbella and Ilyonectria). Different concentrations of biochar affected the bacterial and fungal community structures. Redundancy analysis indicated that the bacterial community was strongly correlated with soil pH, NO-N, and EC, while the fungal community was closely related to soil NO-N and moisture. The network analysis showed that biochar and intercropping affected the symbiosis pattern of the microorganisms and increased the proportion of positive interactions and nitrifying microorganisms (Nitrospirae) in the microbial community. Overall, our results indicated that monoculture and intercropping with biochar improved soil physicochemical states and plant nutrient absorption, and regulated soil microbial communities, these were the main factors to promote tomato growth and increase tomato productivity.
Highlights
Biochar refers to the organic material rich in carbon and stable in nature obtained from biomass pyrolysis at a low temperature under anaerobic or hypoxic conditions (Sun et al, 2016)
We investigated the effects of biochar on tomato growth, soil physicochemical properties, nutrient uptake, rhizosphere microbial community, and symbiosis pattern in the tomato monoculture (T) and tomato/potato–onion intercropping (TO) in continuoustomato soil
These results indicated that intercropping and addition of biochar could improve the plant height, dry weight, and yield of tomato, and the intercropping with the addition of 1.2% biochar had the best effect
Summary
Biochar refers to the organic material rich in carbon and stable in nature obtained from biomass pyrolysis at a low temperature under anaerobic or hypoxic conditions (Sun et al, 2016). It is often used as a soil amendment for sustainable agricultural purposes because of its porous structure, high surface area, and strong adsorption capacity. The documented beneficial effects of adding biochar to soil include an increase in soil pH, soil structure improvement, increased nutrient content, and better crop yield (Gul and Whalen, 2016; Zheng et al, 2018). G. et al, 2018), could provide the basis for developing a strong strategy for sustainable agriculture
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
