Importance of Bacteria to Agriculture
It has been extensively demonstrated that soil microorganisms interact with plant roots and soil constituents in the root-soil interface. This great set of interactions between soil, roots and micro-organisms leads to the development of a dynamic environment called rhizosphere, where a variety of microbial forms can actively develop.
Microorganisms clearly play an important role in processes affecting the transformation of soil phosphorus and their availability to plants. In addition, the continued use of chemical fertilizers represents a significant cost to agriculture worldwide. Therefore, the use of microorganisms as inoculants to mobilize poorly available sources of phosphorus in the soil is an alternative to reduce environmental pollution and improve crop productivity.
Biofertilizers or biological fertilizers are based on microorganisms that promote and benefit plant growth and nutrition. Soil microorganisms, generally fungi and bacteria are more or less deeply naturally associated with plant roots. These microorganisms can facilitate directly or indirectly, the availability of certain nutrients such as nitrogen, phosphorus and water, and produce substances called plant hormones promoting plant growth.
Phosphorus, after nitrogen, is the inorganic nutrient most required by plants and microorganisms, and also, on the ground is the limiting factor for plant development despite being rich in both inorganic and organic forms. Plants must absorb the nutrient from the soil where it’s in very low concentration, typically at levels ranging between 5 and 30 mg kg-1. These nutrient low rates are due to soluble phosphorus reacts with ions such as calcium, iron or aluminum causing precipitation or fixing while reducing its availability to plants.
Inorganic phosphates applied as chemical fertilizers are also immobilized on the soil, and as a result are not soluble, being impossible for crops to use. Therefore, it is considered that the solubilization of phosphate rock and various other sources of inorganic phosphorus by soil microorganisms is a key to increase the amount of nutrients available to plants .
They have been isolated phosphate solubilizing bacteria belonging to the following genera Pseudomonas, Bacillus, Rhizobium, Agrobacterium, Burkholderia, Achromobacter, Micrococcus, Aerobacter, Flavobacterium and Erwinia.
The phosphorus solubilizing microorganisms constitute up to 40% of the population of soil bacteria and a significant portion of them are isolated from the rhizosphere. However, although many bacterial genera exhibit this ability to solubilize inorganic phosphorus is particularly interesting to detect this ability in groups with other properties promoting plant growth, such as ability to fix atmospheric nitrogen.
Microorganisms can also interact with each other, leading in many cases to synergistic interactions favoring plant growth. An example of such synergism is the interaction between mycorrhizae: symbiosis formed by certain soil fungi, and root and phosphorus solubilizing microorganisms. Mycorrhizae have typical structures of nutritional exchange within the root and a rich network of mycelium outside it, which allows the roots to explore more extensively the ground and better use of low mobility elements such as phosphorus.
Microbial inoculants represent a new way of working towards a more sustainable and efficient agriculture; clearly beneficial to society and farmers. This is a clean technology, aligned with the principles of sustainable agriculture, which aims to address the misuse of pesticides and fertilizers in recent times.
So that biofertilization, the use of microorganisms with the ability to promote plant growth is presented as a great alternative. Studies in laboratory, greenhouse trials, and open field trials have shown that the application of these technologies results in clear benefits.
Over recent years, IDEAGRO has extensively worked with bacteria in agriculture, performing different isolates and microorganisms strains developing new products formulated with isolated soil microorganisms that possess the ability to solubilize phosphorus and potassium in the soil and fix nitrogen ambient.
We have also developed many studies with bacteria of the genera Pseudomonas, Bacillus, Azotobacter and Azospirillum, evaluating the effectiveness in different soils, climates and cultures achieving impressive results like increasing phosphorus and potassium availability by approximately + 20/30%, achieving a further increase in the availability of Ca and Mg of an additional 8/10%, with a significance reduction of chlorides and boron.
The set of aspects and improvements achieved results in a more healthy and nutritious crop also achieving a greater resistance to diseases and higher growth performance rate. We are currently working on new beneficious bacteria strains of fast deployment to colonize the soil with bacteria after disinfection preventing possible re-infections with pathogens, as well as developing and testing new formulations that allow us to remain at the forefront in the use of beneficial bacteria in agriculture.
For additional information please contact Pedro Palazón, IDEAGRO Technical Director both by email, palazon [at] ideagro.es, or by phone on 968 118 086. Do not hesitate to ask us about it! In IDEAGRO we have a multidisciplinary team at your disposal.