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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Soil Management and Sugarbeet Research » Research » Publications at this Location » Publication #401523
Research Project: Agricultural Management for Long-Term Sustainability and Soil Health

Location: Soil Management and Sugarbeet Research

Title: Soil bacteriome resilience and reduced nitrogen toxicity in tomato by controlled release nitrogen fertilizer compared to urea

Author
item ROHRBAUGH, CARLEY - Colorado State University
item DIXON, MARY - Colorado State University
item Delgado, Jorge
item Manter, Daniel
item VIVANCO, JORGE - Colorado State University

Submitted to: Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2023
Publication Date: 11/20/2023
Citation: Rohrbaugh, C.R., Dixon, M.M., Delgado, J.A., Manter, D.K., Vivanco, J.M. 2023. Soil bacteriome resilience and reduced nitrogen toxicity in tomato by controlled release nitrogen fertilizer compared to urea. Applied Microbiology. 3(4):1262-1276. https://doi.org/10.3390/applmicrobiol3040087.
DOI: https://doi.org/10.3390/applmicrobiol3040087

Interpretive Summary: This study explored the effect of Environmentally Smart Nitrogen (ESN) on the soil microbiome of tomato (Solanum lycopersicum cv. Rutgers) plants. Plants were grown with high and low rates of either ESN or urea. ESN produced significantly larger total dry plant biomass compared to urea and even when supplied at 1/4 of the rate. The fertilizer type also influenced the soil microbiome with both hgih ESN and urea promting the abundance of microbial nitrifiers.

Technical Abstract: Nitrogen use efficiency (NUE) strategies have been developed to mitigate the negative consequences of improperly applied nitrogen (N) fertilizer. Controlled release fertilizers (CRF), such as Environmentally Smart Nitrogen (ESN), are amongst the strategies supporting NUE. Soil microorganisms are responsible for N cycling and ensuring N availability for plants; however, excess of N applications could be deleterious. Our study explored the effect of ESN on the soil microbiome of tomato (Solanum lycopersicum cv. Rutgers) plants grown in nonsterile and sterile soils to further our understanding of the relationship N has with the soil’s ecosystem and plant development. It was found that ESN produced significantly larger total dry plant biomass compared to urea. This finding suggests that the use of ESN directly improves plant growth, even at a lower N rates in comparison to urea. We also found that high-rate applications of ESN produced significantly larger available pools of nitrate concentration in the soil compared to urea. Shifts in the microbiome composition were found in response to fertilizer type (p<0.05), fertilizer rate (p<0.05), and soil condition (p<0.001). A nonsterile and sterile soil condition were used to compare microbial assembly following fertilizer application. It was found that in the nonsterile soil treatment, high rates of ESN and urea had significantly different microbial composition (p= 0.03) compared to the lower N rates. The high rates of ESN and urea promoted an abundance of microbial nitrifiers under nonsterile soil conditions. In contrast, the microbiomes under high and low rates of fertilizers in sterile soils were similar and limited presence of nitrifiers was detected. Furthermore, nitrifying genes such as PmoA-amoA, hao, and nirA were detected similarly amongst both N types (p<0.005). Genes associated with N fixation, nifH and nifD, were only detected amongst the control (p<0.05). Thus, our data suggest some management strategies that could be used to decrease the deleterious effects of N cycling microbes.