Effects of Soil Microbial Communities on Seed Germination and Seedling Growth of Raphanus sativus (Raddish) Via Application Of Aerated Vermicompost Water Extracts
Location
Village Square
Department
Biology
Abstract
Aerated compost teas (ACTs) are commonly used as an alternative to synthetic fertilizers in small scale agriculture systems. It is believed the microbial consortium made by ACT’s will significantly improve soil microbe diversity and consequently, improve plant development and success. While many studies have investigated the use of compost teas against plant disease suppression, few studies have looked at the effect of ACTs on germination rate and early development of plants. This study hypothesized that plants treated with ACT will demonstrate increased germination and growth rates over plants that are treated with only water. Experiments were broken into two treatments and studied over a two week grow cycle. One treatment set compared seeds that were soaked in ACT for 48 hours prior to being sown and the second set investigated the impact of the ACT inoculated soil against a control. ACT was prepared using commercially produced worm castings, humic-acids, kelp, and alfalfa mixtures, and allowed to brew for 24 hours before application to soils. Community-level physiological profiling of carbon sources was used to determine the differences in soil samples. Soaking seeds in ACT prior to being sown in the soil exhibited lower germination rates than seeds that were soaked in sterile water. Seeds that were sown directly into soil treated with microbial inoculants showed lower growth rates than seeds that were planted into sterile soil and treated with sterile water. These results suggest no significant connection between the application of microbial inoculants and an increase in germination rates or improved early seedling development. This evidence may imply the building of microbial communities in the rhizosphere is not as critical to the success of a plant’s growth as it is in a later, more mature, stage of growth.
Faculty Sponsor
Emily Booms, Northeastern Illinois University
Effects of Soil Microbial Communities on Seed Germination and Seedling Growth of Raphanus sativus (Raddish) Via Application Of Aerated Vermicompost Water Extracts
Village Square
Aerated compost teas (ACTs) are commonly used as an alternative to synthetic fertilizers in small scale agriculture systems. It is believed the microbial consortium made by ACT’s will significantly improve soil microbe diversity and consequently, improve plant development and success. While many studies have investigated the use of compost teas against plant disease suppression, few studies have looked at the effect of ACTs on germination rate and early development of plants. This study hypothesized that plants treated with ACT will demonstrate increased germination and growth rates over plants that are treated with only water. Experiments were broken into two treatments and studied over a two week grow cycle. One treatment set compared seeds that were soaked in ACT for 48 hours prior to being sown and the second set investigated the impact of the ACT inoculated soil against a control. ACT was prepared using commercially produced worm castings, humic-acids, kelp, and alfalfa mixtures, and allowed to brew for 24 hours before application to soils. Community-level physiological profiling of carbon sources was used to determine the differences in soil samples. Soaking seeds in ACT prior to being sown in the soil exhibited lower germination rates than seeds that were soaked in sterile water. Seeds that were sown directly into soil treated with microbial inoculants showed lower growth rates than seeds that were planted into sterile soil and treated with sterile water. These results suggest no significant connection between the application of microbial inoculants and an increase in germination rates or improved early seedling development. This evidence may imply the building of microbial communities in the rhizosphere is not as critical to the success of a plant’s growth as it is in a later, more mature, stage of growth.