Soil Microbes and their Importance in Agriculture & Cannabis Farming
Our environment is made up of living and non-living things. The living things (biotic organisms) are extremely rich in diversity. For example, it is estimated that 99% of microorganisms are yet to be discovered! Microorganisms play vital roles in nature- we will touch on some of their important doings, especially in agriculture and cannabis farming.
Soil microbes are very tiny forms of life which exist as single cells or in most cases, multiple cells. They are found in most of the earth’s living materials and assist in maintaining the ecosystem. Soil microbes are also referred to as soil microorganisms. Of all the living things in the soil, microbes are the most abundant. Such that in every gram of soil, there are at least one million microorganisms while soils very rich in nutrient can have up to 650 million bacteria per gram. They are called ‘micro’ because they can only be seen with the aid of a microscope.
Most of these organisms are present in the soil by nature. However, their abundance can be increased using artificial means such as inoculation. Soil microbes are grouped into several types, of which seven are common. These include; fungi, bacteria, protozoa, archaea, viruses, algae, and helminths (multicellular animal parasites). They improve soil fertility through organic matter decomposition, help in nutrient recycling, soil restoration, ecosystem primary production and overall plant health. Microorganisms like to live in the topsoil due to the abundance of food and organic matter. Also, they are found around the root areas of plant (the rhizosphere) to consume the dead cells and chemical compounds released by plant roots (exudates).
Availability of soil microorganisms indicates the quality of the soil since plants depend on microbes to process organic nutrients into a usable form for plant growth and development (Chen et al., 2003).
Importance of Soil Microbes
Soil microbes contribute to less than one percent of the soil total mass. However, they play uncountable roles in the support of plant and animal life.
Breaking down of organic matter
Soil microbes through their numerous activities help to supply nutrient in the soil. They break down large chunks and complex organic matter into simple and usable chemical compounds. This process hastens the uptake of these minerals by plants. Different groups of soil microbes decompose different forms of organic matter. Their large population helps to breakdown almost all organic matter.
Defends plants from pests and diseases
Microbes are natural defense against diseases and pests. This has been shown in most cases through its usage in large scale production of the soil bacterium Bacillus thuringiensis (Bt), for the control of crop pests especially caterpillar and the larvae of another common cannabis pest, fungus gnats. It has also been used to control the spread of various flies and beetles. Biocontrol agents for fighting against diseases (mostly root diseases) caused by fungi was developed from a genus of fungi called Trichoderma. This has been proved to be effective by many farmers.
Helps in Bioremediation
Bioremediation also known as biological remediation is the use of microbes to remove unwanted and poisonous chemicals from the environment. Due to the excessive use of chemicals such as inorganic fertilizers, pesticide, and pollutions from industries, there is need for bioremediation on soil used for agriculture. It is an intentional process used to eliminate environmental pollutants from contaminated sites (Madsen, 2003). This is done through continuous organic farming. In this process, microbes like fungi and plants break down, isolate and/or remove soil contaminants from the soil.
Nutrient Recycling and Nitrogen Fixation
One of the key roles of microorganisms is the production of oxygen through their decomposition activities and thus, providing nutrients for plants. Root fungi (Mycorrhizae) goes deep into the soil with its thin filament which acts as root extensions. These help to bring up nutrients that have been leached from the topsoil. Mycorrhizae enhances the absorption of water and many nutrient elements (Vrieze, 2015). Microbes help to bring back nutrients to minerals forms (ready for absorption by plants) through a process called mineralization.
In agriculture, Nitrogen is highly needed. The use of inorganic fertilizers contributes only 25% of the required nitrogen. However, biological fixation produces about 60%. Soil microbes especially bacteria transform nitrogen (N2) from the atmosphere into ammonia (NH3). An example is Rhizobium found in the roots of leguminous plants. This increases production and reduces cost/damages done by artificial fertilizers.
Improves soil structure
Soil microbes improve soil structure through their binding activities. They release polysaccharides, glycoproteins and gums that glue soil minerals together. Fungal hyphae and plant roots further bind soil aggregates together. Good structure of the soil is very necessary for proper plant growth and development. Soils with high organic matter content gives the advantage of decrease in volatilization and leaching of nitrogen in the soil (Kramer et al., 2006). After decomposition by microbes, humus is formed. Humus aids the soil to retain water and builds the soil structure. It also improves soil quality by encouraging soil aggregation and aeration, as well as reducing bulk density of the soil (Mitter, et al., 2017 and Pérez‐Jaramillo 2016). It promotes cation exchange capacity of the soil and improves resistance to diseases.
Different types of microbes
Although, there are helpful and unhelpful microbes, helpful microbes are those that have a mutual associations with the plant roots such as rhizobia, actinomycetes, mycorrhizal fungi, and diazotrophic bacteria. They encourage nutrient availability, mineralization, and produce plant growth hormones. The unhelpful microbes are the dangerous ones. These include single cell organism called Phytophthora infestans (fungus), which causes potato blight and other diseases of plant. There are many other bacteria and fungi that lead to the decay of leaves and roots (Vrieze, 2015), that we as cannabis farmers should be wary of.
BioRhize to inoculate your cannabis garden
It’s important that as cannabis growers we supply beneficial microorganisms into our mediums to ensure optimal plant performance. Even in hydroponics settings, microbes can be effective in increasing nutrient availability and deterring against plant pathogenic microorganisms. That’s why it’s important that when using inoculants, they provide both probiotics and organic decomposers that can help nutrient availability while also defending our plants and our roots. The concoction of rhizobacteria found in BioRhize can help in increasing plant growth and maintaining plant health.
Soil microbes for the betterment of crops and humanity
Finally, soil microbes help in improving and restoring soil health and quality by cleaning up contaminated soils, protecting plants from diseases and pests, recycling and making nutrients available for plants. Soil microbes positively affect man and animals since it is a reliable source of many antibiotics and medicines used in fighting diseases. Improve your cannabis farm or garden today by promoting the growth of soil microbes. Increase the organic matter content of your farm for maximum yield and sustainable productivity.
Chen, G., Zhu, H., Zhang, Y. 2003. Soil microbial activities and carbon and nitrogen fixation. Research in Microbiology 154 pp. 393–398
Kramer, S., Reganold, J., Glover, J., Bohannan, B., and Mooney, H. 2006. “Reduced Nitrate Leaching and Enhanced Denitrifer Activity and Effciency in Organically Fertilized Soils.” Proceedings of the National Academy of Sciences of the United States of America 103 (12): 4522–27.
Madsen, E. 2003. Report on Bioavailability of Chemical Wastes with Respect to the Potential for Soil Bioremediation. US Environmental Protection Agency, National Center for Environmental Research.
Mitter, B., Pfaffenbichler, N., Flavell, R., Compant, S., Antoniellli, L., Petric, A., et al., 2017. A new approach to modify plant microbiomes and traits by introducing beneficial bacteria at flowering into progeny seeds. Front Microbiol 8: 11.
Pérez‐Jaramillo, J.E., Mendes, R., and Raaijmakers, J.M. 2016. Impact of plant domestication on rhizosphere microbiome assembly and functions. Plant Mol Biol 90: 635–644.
Vrieze, J. 2015. The littlest farmhands. Science. 349 (6249): 680–683.