BioBead is a biodegradable hydrogel pellet containing fungal and bacterial consortia for soil health and regenerative agriculture. Microbes in this consortia can fix nitrogen (N), solubilize phosphorus (P), and drive carbon (C) cycling. Arbuscular mycorrhizal fungi (AMF) are obligate mutualists that make direct contact with plant roots and hand off N and P to plants, obtaining C in return. They also provide structures for microbial residence and travel. Greenhouse studies with BioBead have demonstrated improved growth for tomatoes and wheat plants, increases in soil organic matter, and promotion of closed nutrient cycling.
In 2025, a greenhouse study led by Renee Davis and Korena Mafune, PhD evaluated the impacts of 14 different microbe inoculations and treatments on soil microbiology, wheat growth, root colonization, and greenhouse gas emissions. This specific project will focus on soil geochemistry, nutrient dynamics, and soil moisture data, with other data being incorporated in subsequent phases. The responses measured at different intervals will have to be analyzed separately, or combined in another manner. These results will provide a foundation for expansion into larger field trials and BioBead formulation improvements in 2026 and beyond, and hopefully become publications and dissertation chapters.
Wheat seedlings (Red Fife variety, Territorial Seeds) were planted in 1-gallon pots containing sunshine mix and sand (1:2 v/v) from September-December 2025 at the UW Biology Greenhouse. The experiment utilized a randomized design with 14 treatments and 7 biological replicates per treatment (98 pots total). Microbial inoculants were applied at planting according to treatment specifications.
Plants were grown for 14 weeks under greenhouse conditions. Plants were watered weekly with 200 mL water, and soil moisture was recorded 24 hours after each watering event. Leachate samples were collected at weeks 0, 2, 4, 6, 8 and analyzed using The Gallery (ThermoFisher) for ammonium, nitrate, and phosphate concentrations.
Plant Root Simulator (PRS) Probes (Western Ag Innovations) were buried at week 6 and retrieved after 14 days. Probes were sent to Western Ag for analysis of soil cation and anion exchange capacity via HPLC. At experiment termination (week 14), above-ground biomass was harvested and weighed, and rhizosphere soil and root samples were collected and stored at -80°C for future DNA extraction and metagenomic sequencing. (These data are mentioned for reference and will not be analyzed in this project.)
2025biobeadgreenhouse.Rmd - R Markdown file containing this document (project overview).
2025greenhousemaster.csv - master data file for multivariate statistical analysis.
Leachates_2025.csv - Ammonium, nitrate, and phosphate leachate concentrations recorded throughout the study. (This is a time series, so temporal autocorrelation may be important.) There is an associated .Rmd file with an exploratory one-way ANOVA.
PRS_GH_2025.csv - Soil anion and cation exchange data from PRS probes. There is an associated .Rmd file with an exploratory one-way ANOVA.
WheatMoistureData_2025.csv - Soil moisture data recorded throughout the study.(This is a time series, so temporal autocorrelation may be important.) There is an associated .Rmd file with an exploratory one-way ANOVA.
wheat yield.csv - Wheat yield data from end of experiment.
N2O_fluxdata.csv - Nitrous oxide flux reported as N"[2]*"O-N/sqmt/hr. Calculated from peak area.
| Code | Full Name | Units | Range |
|---|---|---|---|
| NH4-N_ugml | Ammonium | ug/mL | 0.01-5.24 |
| NO3-N_ugml | Nitrate | ug/mL | 0-97.55 |
| PO4-P_ugml | Phosphate | ug/mL | 0.05-31.97 |
| % soil moisture | Percent Soil Moisture | n/a | 0-100 |
| NO3-N | Nitrate | ug/10cm^2^/14 days | 0.8-8.3 |
| NH4-N | Ammonium | ug/10cm^2^/14 days | 0-2.9 |
| P | Phosphorus | ug/10cm^2^/14 days | 6.8-23.7 |
| Ca | Calcium | ug/10cm^2^/14 days | 751-2220 |
| Mg | Magnesium | ug/10cm^2^/14 days | 158-477 |
| K | Potassium | ug/10cm^2^/14 days | 146-305 |
| Fe | Iron | ug/10cm^2^/14 days | 2.5-21.5 |
| Mn | Manganese | ug/10cm^2^/14 days | 0.3-1.5 |
| Cu | Copper | ug/10cm^2^/14 days | 0-1 |
| Zn | Zinc | ug/10cm^2^/14 days | 1.3-3.8 |
| B | Boron | ug/10cm^2^/14 days | 0-0.6 |
| S | Sulphur | ug/10cm^2^/14 days | 105-490 |
| Pb | Lead | ug/10cm^2^/14 days | 0-0.9 |
| Al | Aluminum | ug/10cm^2^/14 days | 3.4-9.5 |
| Cd | Cadmium | ug/10cm^2^/14 days | 0-0.2 |
| Na | Sodium | ug/10cm^2^/14 days | 943-2734 |
| GrainWeight_g | Grain weight | g | 0.6-2.7 |
| Harvest_Index | Harvest index | n/a | 0-0.6 |
| N2O-N_flux | Nitrous oxide N flux | ug N2O-N/sqmt/hr | -38-3557 |
| Code | Full Name | Units | Range/Values |
|---|---|---|---|
| Fungi | Arbuscular mycorrhizal fungi added | Binary | Present/absent |
| Bacteria | Bacterial consortia added | Binary | Present/absent |
| Hydrogel | BioBead hydrogel carrier | Binary | Present/absent |
| Dose | Inoculum dose | Categorical | Full (100%), Half (50%) |
| GR24 | Synthetic strigolactone addition (5 nM) | Binary | Present/absent |
| Week | Sampling week | Integer | 1-8 |
| Treatment | Treatment code | Categorical | T1-T14 (see below) |
T1 - BioBead – bacteria
T2 - BioBead – AMF
T3 - BioBead - bacteria, AMF
T4 - SL-primed BioBead - bacteria, AMF
T5 - SL-primed BioBead - bacteria
T6 - SL-primed BioBead - AMF
T7 - BioBead w/ reapplication at week 8
T8 - ½ fertilizer ½ BioBead
T9 - Liquid consortia
T10 - Commercial biofertilizer (Hardygro)
T11 - Empty bead
T12 - SL-primed empty bead
T13 - Synthetic fertilizer (positive control – 10% dose, 0.6 g/L, 10mL/pot)
T14 - Untreated
Specific replicates of samples are indicated after a dash in the sample code. For example, certain replicates in the PRS data are designated as T1-1, T1-2, T1-3, etc.