Nanobubble Research: How nanobubbles improve greenhouse tomato crops

For years, researchers across the world have been conducting trials on a wide variety of crops to analyze the benefits of oxygen nanobubble-enriched irrigation water.

This blog takes a look at some of these studies focusing on greenhouse tomatoes.

But first, here is a quick review of how nanobubbles change water, providing a myriad of natural, chemical-free benefits related to super-oxygenation and the power of nano-sized bubbles.

Benefits of Nanobubble Technology in Agriculture

Nanobubble technology has the highest gas transfer efficiency compared to traditional aeration technologies, delivering over 85% oxygen transfer efficiency versus 1% - 3% per foot of water for aeration. What’s unique about oxygenation with nanobubble technology is that nanobubbles produce stable dissolved oxygen (DO) concentrations that last for weeks to even months. This allows growers to achieve optimal and economical DO concentrations, which supports plant health and crop production in several ways:

1. Enhanced Root Growth: Oxygen is essential for plant respiration and energy production, and optimal DO concentrations can promote more efficient root respiration, leading to stronger and more extensive root systems. This enables plants to absorb nutrients more effectively, resulting in increased growth and yield.
2. Improved Nutrient Uptake: Dissolved oxygen in soil or water facilitates the uptake of essential nutrients such as nitrogen, phosphorus, and potassium by the plant roots. This results in better nutrient utilization and can promote faster growth and better crop yields.
3. Reduced Pathogens: Higher DO concentrations can also reduce the prevalence of soil-borne pathogens, such as harmful bacteria and fungi. This is because many plant pathogens are anaerobic, meaning they thrive in low-oxygen conditions. Increasing oxygen levels creates a less favorable environment for pathogens, reducing the risk of crop disease.

In addition, the physical-chemical characteristics of nanobubbles have their own slew of benefits. Nanobubbles are tiny bubbles with a diameter of less than 200 nanometers. When nanobubbles are introduced into water or nutrient solutions, they can help improve crop health and production by:

1. Improved nutrient uptake: Nanobubbles can increase the solubility of nutrients such as nitrogen, phosphorus, and potassium in water. This increases the availability of nutrients to the plant roots, promoting faster and healthier growth.
2. Disease control: Nanobubbles can help control pathogens and diseases like Pythium, Fusarium, and Phytophthora, by improving water quality, lysing and degrading bacterial cells and reducing the biofilm formation in irrigation systems. This helps farmers reduce the need for chemical pesticides, fungicides and cleaning products.
3. Increased yields: By improving nutrient uptake, oxygenation, and disease control, nanobubbles can increase crop yields and improve the overall quality of the crop.
4. Water conservation: Nanobubbles can improve the water-holding capacity of soil and soil substrates and improve water uptake efficiency, reducing the amount of water needed for irrigation. This can help farmers conserve water and reduce their environmental impact.
5. Water surface tension reduction: Nanobubbles also reduce the surface tension of water, allowing for better infiltration rates into soils and substrates, getting water to the root zone where it’s needed most.

Nanobubble generators are a proven, efficient, and cost-effective technology. This is why they are being adopted by more and more agricultural and horticultural operations around the world – greenhouses, specialty field crops (e.g. blueberries) and orchards – in addition to various water pollution and remediation applications.

Nanobubbles Improve Organic greenhouse Tomato Growth and Productivity

Published in the Journal of Agricultural and Food Chemistry, a study by a team of scientists from Italy, the UK and China found that organic tomato plant growth and productivity were enhanced through nanobubble-enriched irrigation. The team compared nanobubble oxygenation to traditional pump oxygenation in soil column experiments.

Soil microbial biomass, activity and diversity were significantly improved due to the oxygenation treatments. In addition, microbial metabolic functions improved, and the tomato yield increased by 23% compared to the control group.

Nanobubbles Enhance Water Use Efficiency Resulting in Better greenhouse tomato and cucumber Crops

In this study published in the Journal of Cleaner Production, nanobubble-enriched irrigation water significantly increased many greenhouse tomato and cucumber plant performance parameters.

The researchers attribute these results mainly to the increased soil oxygen content and retention time caused by the presence of nanobubbles. 

Nanobubble Oxygenation Improve Yield, Water Use Efficiency & Soil Quality in Two-Season Tomato Study 

When this team from China conducted tomato experiments over two consecutive growing seasons, they focused on the seeding, flowering and fruiting stages. The team compared plant performance under the application of water with a standard dissolved oxygen (DO) concentration of 15 mg/L and super-oxygenated nanobubble-enriched water of 25 mg/L on yield, water use efficiency, fruit quality and soil quality. 

“The results indicated that application of [nanobubble-treated water] resulted in higher yield and water use efficiency of tomato and cucumber compared to no-oxygenation treatments,” the scientists state in their paper in the Journal of Agricultural Water Management. “Additionally, [nanobubble] application improved soil quality by increasing rhizosphere soil urease and phosphatase contents and soil microbial species, which promised to stimulate crop root growth and accumulate soil available nutrients.” 

Nanobubbles Promote Healthier Root Systems for Tomato Greenhouse Crops Through Rhizosphere Health

Rhizosphere hypoxia severely inhibits plant growth, reducing water use efficiency and yield. However, as noted by a research team from Spain and China in a 2022 paper published in the Journal of Cleaner Production,  irrigation with nanobubble-treated water is an efficient method to ameliorate hypoxic conditions and promote greenhouse tomato plant growth.

The results showed that several critical plant performance parameters were significantly improved through the application of nanobubble-enriched water.

Results compared to the control:

• Increased fruit yield: +7.1%–34.5%
• Increased soluble sugar: +6.9%–60.5%
• Increased vitamin C: +17.5%–73.8% 

The team also found that bacterial functions of methanol oxidation, nitrogen fixation, aerobic chemoheterotrophy and cellulolysis were more abundant in nanobubble-treated soils, resulting in better crop yield, water use efficiency and soil fertility.

Nanobubbles Produce More Efficient Uptake and Water Usage for greenhouse Tomato Crops

NovaCropControl, an industry-leading research and test center, conducted a side-by-side study on tomato crops irrigated with and without nanobubble-enriched irrigation water.

The tomato plants irrigated with nanobubbles had:

1. More efficient nutrient uptake and water usage
2. Improve capillary root development
3. Increased resilience to high heat
4. Reduce Pythium levels of up to 80%

These last two tomato studies show some of the many benefits of providing irrigation water with higher DO but do not involve nanobubbles. Please note that nanobubble-treated water typically has a DO content of over 20 mg/L. 

Dissolved Oxygen Supports Healthy Tomato Crops

Published in the Agriculture Water Management journal, a group of Chinese researchers analyzed DO levels of 4, 6, 7.5 and 9 mg/L on the growth, photosynthesis, yield and quality of tomatoes and changes in soil microbes.

They found that many parameters were higher in the top DO group compared to the control.

Results from 9 mg/L DO Group:

• Leaf Area Index: +25.6%
• Net photosynthetic rate: +12.9%
• Vitamin C: +38.4%
• Soluble sugar content: +18.3%
• Lycopene content: +18.6%
• Dry matter accumulation: +15.3%
• Soil respiration rate: +48.3%
• Soil microbial carbon content: +46.7%
• Soil microbial nitrogen content: +27.4%

This group also found that as DO of irrigation water increased, soil organic carbon increased, the soil environment was improved, and the plant growth rate increased. These effects, they said, are conducive to improved water use efficiency and fruit quality. 

Another study published in the European Journal of Plant Pathology examined tomato plant growth and root resilience against the pathogen Pythium F707. Plants receiving a high DO treatment resulted in a “marked” growth increase.

These plants did not exhibit the typical symptoms of root decay and infection within 6 days after inoculation with Pythium but remained healthy throughout the experiment.

Nanobubble technology continues to be supported by third-party research, showing that both nanobubbles and oxygen are key to healthy tomato crops. Nanobubbles improve root zone conditions, allowing for better root development and healthier crop growth. Moleaer has seen these results with our customers in over 1000 irrigation applications worldwide. Growers are achieving higher and better-quality yields while reducing inputs like fertilizer, water, soil amendments and chemicals.

 Visit our case studies page to learn more.