Water management is becoming increasingly difficult and expensive for growers, turf managers and arborists. Rising municipal water prices and water restrictions that are now in place in more and more areas are adding to the already difficult task of irrigation management. New technologies that help to cut back the need for water use without affecting plant quality are badly needed. The increased use of beneficial bacteria and humic substances is becoming increasingly commonplace to help turf managers solve these problems.
Scientific studies and field studies have demonstrated significant water and subsequent cost savings using a combination of beneficial bacteria and humic acids. This dual approach to water retention and delivery has an additive effect in creating a more hospitable environment for plant, tree and turf growth, especially during hot or dry periods. Adding beneficial bacteria and the humic substances together only enhances the water retention abilities of soil, as proven with extensive field testing. The picture to the right demonstrates this principle. These vincas received 64 ounces of water each; they were then not watered for 6 days. The vinca on the right received a treatment of a combination of beneficial bacteria and humates with the watering (2% Microbe Life). The vinca on the left did not. The untreated vinca is succumbing to the effects of drought, while the vinca that received the treatment remains healthy and turgid, even after the six days without water.
Beneficial bacteria help to retain and provide water through multiple mechanisms. First, the cellular content of a prokaryotic bacterial cell is any where from 60% to 80% water1,2. That means that the majority of what is being added to soil when inoculating with beneficial bacteria is water. Also, the bacterial biomass provides a giant “buffering” and retention system for the water that does not make water available unless it is needed. When water is available, the bacteria divide and incorporate it into their cell bodies. When conditions become dry, the bacteria can re-release this water to make it available to the turf or plant again. Since excess sitting water can lead to disease and pest pressure (from organisms such as pathogenic fungi, or providing a breeding ground for mosquitoes), having the water buffered in bacterial cells as opposed to sitting or pooling provides multiple advantages. Second, bacteria store and retain water in biofilms. Beneficial biofilms are polysaccharides (sugars) secreted by beneficial bacteria that they use to retain nutrients and water. Polysaccharides can bind many times their weight in water3.
This is a tremendous amount of water retained in the soil that would otherwise wash through or evaporate. This water is also concentrated in the rhizosphere around the root zones, where the microbes are concentrated. Third, beneficial microbes produce water as a by-product of their normal functions for such metabolic activities as bacterial photosynthesis4 and the cycling of nitrogen (nitrification). When you breathe onto a mirror or glass, you will see the water that your body expels as a by-product of its metabolism. Having billions of bacteria constantly “breathing” in the soil is analogous to this process. The water the bacteria produce is released into the soil. Fourth, the decomposition of organic matter releases water, and this process is driven by microbes in the soil. By adding beneficial microbes, the decomposition of organic material (such as the breakdown of thatch) is accelerated, and water is consequently made available to plants and turf. For every 1 gram of organic material, any where from 0.5 to 0.75 of a gram of water is produced.5 Adding supplemental microbial life to the soil is a significant source of constant water production.
Humic substances also help retain and release water in the soil. Humic substances are large organic molecules6 that are the end-products of the decomposition of organic matter:
They are an excellent source of organic matter. Additionally they are also a great way to bind and retain micronutrients near the root system of plants that would otherwise be lost. Humic substances contain a mixture of large, highly charged organic molecules. These molecules act like sponges, and are able to hold seven times their volume in water. Most of the organic matter in soil is in the top 2-8 inches, or where the roots are, humic substances provide another system that can release this water when the soil dries out, and right at the root zone where a plant needs it most.
Integrating a combination of beneficial bacteria and humates (such as that found in the Microbe Life technology) will dramatically reduce your water use, and the subsequent labor and costs associated with irrigation, while improving the look and health of your turf and plants and decreasing drought stress.
- Jeffrey C Pommerville. In Alcamo’s Fundamentals of Microbiology. 2010. Jones and Bartlett Publishers LLC.
- Bratbak G, Dundas I. Bacterial Dry Matter Content and Biomass Estimations. Applied and Environmental Microbiology. 1984. Vol 48 (4): 755-757.
- C. Fringant, J. Desbrières, M. Milas, M. Rinaudo, C. Joly, M. Escoubes. Characterisation of sorbed water molecules on neutral and ionic polysaccharides. International Journal of Biological Macromolecules. 1996 18 (4): 281-286.
- Foster JW. The Role of Organic Substrates in Photosynthesis of Purple Bacteria. The Journal of General Physiology. 1940 24 (2): 123-34.
- Miller F. In Soil Microbial Ecology. 1993 (pg 524).
- Stevenson FJ. In Humic Chemistry: genesis, composition, reactions. 1982. Wiley, NY