Microbially Induced Carbonate Precipitation: A biological alternative to liming

Commodities

Practices

Nearly 4000 million hectares of arable land are affected by soil acidity globally (Hirzel et al., 2023). Current methods for managing soil acidity in croplands rely heavily on lime application or long-term crop breeding for acid resilience. These strategies are effective, but they are slow, expensive, and sometimes inaccessible to resource-limited farmers. Our proposed work will move beyond conventional approaches of addressing soil acidification by targeting plant growth-promoting microorganisms capable of Microbially Induced Carbonate Precipitation (MICP) and evaluating their capacity as inoculants to increase soil pH, decrease metal bioavailability, and increase plant vigor and yield. Developing microbial inoculants that can improve plant growth while simultaneously contributing to neutralizing pH may offer an alternative pathway with broad applicability. Microbial consortia inoculated as a seed coat or as alginate encapsulation can be adapted to both smallholder farms and large-scale industrial agriculture and could reduce reliance on repeated lime applications and sustain productivity on acidifying soils. We will work closely with producers dealing with the impacts of soil acidification in soil mesocosm experiments to demonstrate proof-of-concept for a biological alternative to liming that could be used to inform future field experiments. Expected outcomes include quantification of MICP-driven pH changes in acidic agricultural soil, identification of microbial consortia with the greatest liming potential, characterization and expression of MICP-associated genes under carbonate-precipitating conditions, and evaluation of the economic feasibility of this approach relative to conventional liming practices. Overall this approach could reduce input costs, improve soil health, and contribute to grain production practices.

Research Objectives:

Obj 1. Quantify the potential of microorganisms capable of MICP to increase soil pH and decrease metal bioavailability in soil mesocosm experiments and evaluate interactions between soil pH and snow mold-associated fungal abundance.

Obj 2. Identify the molecular mechanisms that govern MICP in the rhizosphere by explicitly linking genomic DNA to ecological function.

Educational Objectives:

Obj 1. To guide future research on MICP as a biological alternative to liming within agroecosystems.

Obj 2. To guide agricultural practices in the inland Pacific Northwest through sharing the results of this study with producers and agricultural stakeholders.

Obj 3. To increase the awareness of the general public on the benefits of soil-plant-microbe interactions within an agricultural context.