Plants thrive in soils with good structure, great microbial activity, and available nutrients to develop healthy, fibrous root systems and produce quality crops. However, poor soil conditions from over-farming, cyclical drought, and poor water quality have led to soils with low nutritional content and have increased challenges with soil & crop management. Traditional methods to improve soil health are often costly and time-consuming. However, innovative Agtech like nanobubble technology offers farmers a sustainable, cost-effective way to improve soil health and water quality, resulting in improved crop yields and plant performance.
Nanobubbles are extremely small bubbles, 70-120 nanometers in size or 2500 times smaller than a single grain of salt. They can be formed using any gas and injected into any liquid. The small size of nanobubbles produces unique chemical and physical properties, improving many aqueous processes in various industries.
In agriculture, nanobubbles have been scientifically proven to improve soil health and structure through natural soil flocculation, nutrient conversion, and microbial activity recovery. In addition to soil health improvements, nanobubbles affect how soils and water interact by reducing the surface tension of water for improved infiltration and wettability.
Nanobubbles Reduce Soil Compaction
Nanobubble-treated irrigation water increases soil flocculation, in which individual clay particles are pulled together into larger aggregates. This reduces soil compaction, allowing better water infiltration and healthier root development.
Giddings, a blueberry grower in Chile, trialed nanobubble-treated irrigation water from July 2020 to April 2021 to study how nanobubbles improve soil compaction. A Moleaer generator injected nanobubbles into the main storage tank of the irrigation system and provided a 50% increase in dissolved oxygen (DO).
Overall, Giddings saw a 20% reduction in soil compaction compared to the untreated control. The reduced compaction resulted in better water infiltration and enhanced root development, enabling increased new shoot growth and improved fruit size, quality, and rate of ripening.
Nanobubbles Improve Nutrient Absorption
Nanobubbles cause an increase in the dispersion of ions in a liquid because they possess ionic mobility. In irrigation water, this means nutrient ions achieve a more homogenous concentration, resulting in a more homogenous dispersion of nutrients in the soil. Nanobubbles also break down larger aggregates of nutrients, allowing more absorption of nutrients by root cells.
Nanobubbles Enhance Soil Microbiology
Nanobubbles improve beneficial microbial activity in the soil and soil mineralization, nutrient conversion, and nitrous oxide emissions partly because they super-oxygenate irrigation water in the soil. As a result, reduced chemical and soil amendments are required, reducing carbon emissions and operating costs.
Nanobubble Increase Soil Oxygenation
Root respiration, an essential function of plant roots, requires oxygen (O2) in soil or substrate to take up nutrients and water necessary for healthy root and plant growth. In soils with heavy clay or poor structure, pore space and oxygen availability are limited.
Nanobubbles super-oxygenate irrigation water, increasing the availability of dissolved oxygen.
When root cells absorb water with very high dissolved oxygen levels, their metabolic rates increase. Thus, they can continually absorb more nutrients and water from the soil.
Additionally, root cells receiving more oxygen grow faster and spend less energy-absorbing nutrients while also benefiting from the favorable environment created by higher oxygen levels in the root zone. Beneficial microbes flourish in aerobic environments while at the same time inhibiting the growth of pathogens.
In 2020, in partnership with Gama Research Center, a Chilean avocado grower began a two-year study of the effects of providing avocado trees in clay soils with super-oxygenated, nanobubble-enriched irrigation water. Compared to others, the avocado tree is susceptible to root asphyxia, and a significant percentage of the country’s avocado orchards are located in clay soils.
They found that in-line nanobubble-treated irrigation water had dissolved oxygen of 15 ppm, almost double that of the control water (8 ppm).
In 2020, the avocado growers observed a very significant fruit size increase (an increase of 40% in fruit in size category ’50’) and improved vegetative tree growth and productivity in the avocado trees receiving nanobubble enriched irrigation water.
Nanobubbles Improve Infiltration & Wettability
Improving the infiltration and penetration rates of poor-quality soils, such as compacted or over-worked, can be challenging. One way to enhance infiltration without amending soils is to reduce the surface tension of water.
Of all liquids, water has an extremely high surface tension due to the powerful bonding of water molecules. Infiltration of untreated irrigation water into the soil can be less than ideal because water molecules are much more attracted to each other than soil particles. Instead of moving down through the soil to the root zone, irrigation water pools on the soil surface and is wasted to evaporation, runoff, or both.
In soils that have dried out entirely or in hydrophobic soils that contain large amounts of water-repelling organic molecules called hydrophobes, the problem of poor infiltration is more severe.
Nanobubbles naturally and efficiently reduce the surface tension of water, acting as a surfactant to reduce water’s intermolecular forces.
Water with reduced surface tension behaves differently on the surface of soils compared to water with high surface tension. As depicted below, water with reduced surface tension has a lower ‘contact angle’ than the soil surface, resulting in better water penetration and distribution in hydrophobic soils.
Water with reduced surface tension also can penetrate compacted soil zones, preventing pooling and runoff.
Nanobubbles Enhance Salts Leaching
In many orchards, soil salinity is a serious problem that reduces yield and negatively impacts tree health. The presence of sodium in the soil causes it to constrict and for water infiltration to be significantly reduced. Additionally, when water cannot travel deeply into the soil, a concentrated ‘head’ of salt often forms in the middle of the root zone, eventually leading to tree death.
Because nanobubbles significantly increase irrigation water infiltration, they provide a permanent and effective solution. This was observed among other horticulture businesses at Maricopa Orchards in California’s Central Valley, where high soil salinity and poor water infiltration were severe problems.
As described in a recent article in Irrigation Leader, Maricopa Agronomy Manager Joe Coelho measured irrigation water infiltration and root zone salt levels before and after a Moleaer nano bubble generator was installed. In the area receiving nanobubble-treated irrigation, water reached a depth of 46 inches, allowing salts to leach beyond the root zone.
Nanobubbles naturally enhance irrigation water and soils
- Lower water surface tension promotes improved infiltration, enabling many positive effects from higher yields to lower root zone salinity
- Increased soil flocculation leads to reduced compaction and enhanced root growth
- More homogenous dispersal of nutrient ions increases nutrient availability in the soil
- Super-oxygenation leads to a higher activity of beneficial soil microbes, more water and nutrient absorption by root cells, and more
- Improve salts leaching to remove salts from root zone for better plant and root health
Nanobubble technology is a chemical-free, cost-effective solution to enhance irrigation water in the soil, providing a range of essential and unprecedented benefits.
You can learn more by watching this exciting webinar with one of the founders of Moleaer, describing how the technology works and reviewing several case studies showing success with the product.