Biofertilizer technology has shown enhanced plant growth in a number of different plants and different soil conditions. Different microbial species can increase plant phosphorus uptake, fix nitrogen, produce auxins (plant growth hormones) and increase availability of other mineral nutrients.
Here’s a good definition from Advances in Applied Microbiology. Biofertilizers are defined as substances containing living microbes, which when applied to seed, plant, or soil promote growth by the supply of essential nutrients such as N, P, and other mineral nutrients. I would add that Biofertilizers enhance plant growth by producing auxins and siderosphores.
Phosphorus is needed in plant cells for a number of purposes including photosynthesis, DNA, respiration and energy storage. Phosphorus is typically an expensive input for farmers. Additionally, phosphate runoff has become an environmental problem and a major issue in certain parts of the country. Phosphate is considered a growth limiting nutrient.
Biofertilizers can help reduce the amount of phosphorus that needs to be applied to crops. Certain species of biofertilizers sometimes called Phosphate Solubilizing Microorgainsms (PSM), such as Bacillus subtilis, and Trichoderma, can solubilize phosphate making the phosphate available to the plant. By increasing Phosphate uptake, plant yield can be increased.
Nitrogen is an essential element for life. In plants, Nitrogen is needed in amino acids, proteins, DNA and chlorophyll. Atmospheric nitrogen is very plentiful but difficult to plants to use because atmospheric nitrogen (N2) is relatively inert, meaning that it does not easily react with other chemicals. So plants need the nitrogen in another form. This is where microorganisms in biofertilizers comes into play. Nitrogen fixation occurs when microorganisms convert atmospheric nitrogen (N2) into ammonia (NH3). Ammonia is easily utilized by plants.
Nitrogen fixation can be performed only by certain types of microorganisms including Rhizobium and Paenibacillus. The use of nitrogen fixation biofertilizers has become common in soybean and peanut production. Typically, the biofertilizer is applied as a seed treatment.
Plant Growth Promoting Rhizobacteria (PGPR) are a type of biofertilizer. This type of biofertilizer first became known around 1970, but just in the last few years have they become more popular. Rhizobacteria (Rhizo means root zone) are bacteria that have formed a symbiotic, or mutually beneficial relationship, with plant roots.
The bacteria are attracted by the plant exudates, chemicals that the plant roots give off. In turn, the bacteria produce a number of chemicals that help the plant. Specifically, these chemicals help the plant grow bigger and better root systems. With a better developed root system, the plant is healthier and will produce better yields. Rhizobacteria are known to produce a number of growth hormones such as auxins and gibberellins. These compounds are particularly useful when they are available at the beginning of root formation.
Typical usage is at the beginning of the planting cycle or at the transplant phase. Rice, corn, peppers, palm, are just some of the crops that will benefit from usage of a quality biofertilizer.
In addition to the benefits I’ve listed above there are more benefits to biofertilizers, including:
The use of biofertilizers is expected to grow dramatically over the next decade. As usage increases, more research will be performed in this area. I expect we’ll see many more benefits of biofertilizer usage in the coming years.
Bill Baugh is a product manager for Custom Biologicals, Inc. a manufacturer and distributor of innovative microbial products. You can visit their website at Living-Soils.com and he can be contacted at 561.797.3008 or Bill@Custombio.biz.