Under the dual challenges of the rapid increase in the global population and the intensification of climate change, the traditional agricultural model is facing severe tests. The production mode that overly relies on chemical fertilizers and pesticides not only exacerbates environmental pollution but also leads to the imbalance of soil microbial communities, further reducing the nutrient utilization efficiency. As an emerging green technology, bio-based material amendments offer new ideas for enhancing soil health and crop productivity. So, how do bio-based material amendments improve nutrient utilization efficiency and boost crop yields?
The research team led by Professor Gang Wang from China Agricultural University systematically summarized the synergistic effects of bio-based material amendments such as microbial inoculants, nanomaterials, and biochar in improving soil health and crop productivity through a review article. The relevant research has been published in the journal Frontiers of Agricultural Science and Engineering (DOI: 10.15302/J-FASE-2024586).
Studies have shown that plant growth-promoting rhizobacteria (PGPB) significantly enhance nutrient utilization efficiency through functions such as nitrogen fixation, phosphorus solubilization, and potassium solubilization. The combined inoculation of nitrogen-fixing bacteria and phosphorus-solubilizing bacteria can increase the nitrogen and phosphorus uptake of wheat. The extracellular polymeric substances (EPS) secreted by them can also enhance the soil's water retention capacity, increasing the biomass of tomatoes in a high-salt environment. In the remediation of heavy metal pollution, PGPB can increase the removal rate of chromium (VI) through bio-adsorption and transformation, while reducing the application amount of chemical fertilizers.
Nanomaterials have demonstrated unique advantages in precision agriculture. Fe₃O₄ nanoparticles can promote biological nitrogen fixation in leguminous plants and increase soybean yields. Silica nanomaterials can inhibit the invasion of pathogenic bacteria through a physical barrier, reducing the incidence of tomato stem blight. Nano slow-release fertilizers can improve nitrogen utilization efficiency by controlling the nutrient release rate and reduce the application amount compared with traditional fertilizers. It is worth noting that under drought stress, nanomaterials can also reduce the malondialdehyde content in wheat by regulating the plant's antioxidant system.
As an efficient carbon carrier, biochar has a porous structure that can adsorb heavy metals and provide habitats for microorganisms. Corn straw biochar loaded with phosphorus-solubilizing bacteria can increase the available phosphorus content in the soil, promote the formation of soil aggregates, and increase the organic carbon storage in black soil. In the remediation of mine soil, the combined application of biochar and manganese-oxidizing bacteria can increase the removal rates of lead and arsenic, and its carbon sequestration effect is remarkable.
The synergistic application of these three shows significant advantages: the combination of microorganisms and nanomaterials can improve the nitrogen utilization efficiency of rice, and the combined remediation of biochar and microorganisms can restore the enzyme activity of mine soil. The research points out that biochar, as a microbial carrier, can extend the survival time of microbial agents, and the targeted delivery characteristics of nanomaterials can enhance the remediation efficiency of biochar.
Although bio-based material amendments show significant potential in improving soil health and crop productivity, their large-scale application still faces multiple challenges. In the future, researchers need to reduce the production cost of materials through process optimization, improve the environmental risk assessment system, and promote policy coordination to achieve the field application of bio-based material technologies.
DOI: 10.15302/J-FASE-2024586