Symbiotic Nitrogen Fixation in Non-legumes: N-supply, Yield and Quality Effects in Tomato and Pepper

View the project final report

Commodities

• Vegetables: peppers, tomatoes

Practices

• Crop Production: application rate management, biological inoculants, food product quality/safety, greenhouses, tissue analysis
• Production Systems: hydroponics
• Sustainable Communities: sustainability measures, urban agriculture

Nitrogen fertilization application is a common component of agricultural systems. However, nitrogen fertilizer production, transport, and application consumes large quantities of non-renewable fossil fuels. Soluble N applications are also prone to environmental losses via runoff, leaching or erosion, incurring an economic loss to farmers and causing considerable water quality degradation. Biological Nitrogen Fixation (BNF) via bacterial endophytes is commonly used in leguminous crops as a sustainable means to capture atmospheric N and deliver it as usable nitrogen directly to plant tissues. This significantly reduces both fertilization requirements and environmental losses. Incorporating BNF into non-legumes would lead to a revolution in agriculture. To gain greater insight into employing nitrogen fixing bacteria in other important agricultural crops, this project aims to investigate the use of the novel diazotroph, Gluconacetobacter diazotrophicus, on two important non-leguminous vegetables, peppers and tomatoes. The goal of the project is to assess usage of this bacteria as a means to reduce external nitrogen application requirements, as well as to quantify yield and nutritional differences. The findings will not only advance the understanding of BNF usage and economic viability for these two vegetables, but can also be employed as a model for investigating the impact of bacterial endophytes across a wide range of crops.

Objectives: The goal of this research is to evaluate the effect of inoculation of non-legumes with the BNF bacterium, Gluconacetobater diazotrophicus (Gd) . My specific objectives are:

1. Detail the impact of Gd inoculation of tomatoes and peppers on vegetative plant growth and fruit yield.

2. Evaluate if BNF with Gd can replace external N requirements

3. Assess effects of Gd on fruit nutrient content

4. Evaluate the economic value of Gd inoculation

5. Use mass balancing techniques to evaluate the efficacy and amount of atmospheric nitrogen capture in inoculated plants.