[:en]It has been widely demonstrated that Soil microorganisms interact with plant roots and soil constituents at the root-soil interface. This large set of interactions between soil, roots and microorganisms gives rise to the development of a dynamic environment known as rhizosphere, where a variety of microbial forms can develop actively and in balance.
Microorganisms clearly play an important role in processes that affect the transformation of phosphorus in the soil and its availability to plants. In addition, the permanent use of chemical fertilizers supposes a significant cost for agriculture worldwide. For this reason, the use of microorganisms as inoculants to mobilize poorly available phosphorus sources in the soil constitutes a alternative to reduce environmental pollution and improve crop productivity.
Bio-fertilizers or biological fertilizers are based on microorganisms that promote and benefit nutrition and plant growth. These are soil microorganisms, generally fungi and bacteria, which are naturally associated with plant roots in a more or less intimate way. These microorganisms can directly or indirectly facilitate the availability of certain nutrients such as: nitrogen, phosphorus and water, in addition to producing substances called phytohormones that promote plant growth.
Phosphorus, after nitrogen, is the inorganic nutrient most required by plants and microorganisms and, furthermore, in the soil it is the limiting factor for plant development despite being abundant in both inorganic and organic forms. Plants must absorb it from the soil, where it is found in very low concentration, normally at levels that vary between 5 and 30 mg kg-1. These low levels of the nutrient are due to the fact that soluble phosphorus reacts with ions such as calcium, iron or aluminum that cause its precipitation or fixation, reducing its availability for plants.
Inorganic phosphates applied as chemical fertilizers are also immobilized in the soil and as a consequence are not soluble to be used by crops. Therefore, it is considered that The solubilization of different phosphate rocks and other sources of inorganic phosphorus by soil microorganisms is a fundamental alternative to increase the amount of nutrients available to plants.
Phosphate solubilizing bacteria belonging to the genera Pseudomonas, Bacillus, Rhizobium, Agrobacterium, Burkholderia, Achromobacter, Microccocus, Aerobacter, Flavobacterium and Erwinia have been isolated from different soils.
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 have this ability to solubilize inorganic phosphorus, It is of particular interest to detect this ability in groups that have other properties of plant growth promotionsuch as, for example, the ability to fix atmospheric nitrogen.
Microorganisms can also interact with each other, giving rise, in many cases to synergistic interactions that favor plant growth. An example of this synergism is the interaction between mycorrhizae: a symbiosis formed by certain soil and root fungi and phosphorus solubilizing microorganisms. Mycorrhizae have typical nutritional exchange structures inside the root and an abundant network of mycelium outside it, which allows the root to explore the soil more extensively and make better use of low-mobility elements such as phosphorus.
Microbial inoculants represent a new way of working in favor of a more sustainable and efficient agriculture that is clearly beneficial for society and agricultural producers. It is a clean technology, aligned with the principles of sustainable agriculture, and which aims to deal with the abusive increase in the use of pesticides and fertilizers in recent times.
This way, the use of microorganisms with the capacity to promote plant growth, is presented as a great alternative of biofertilization. Controlled studies in the laboratory, greenhouse, and in a more natural way in the field, have shown that the application of these technologies results in clear benefits.
During the last years, at IDEAGRO, we have worked extensively with bacteria, isolating different strains of microorganisms and developing new formulations based on microorganisms isolated from the soil that have the ability to solubilize phosphorus and potassium present in the soil, as well as fix environmental nitrogen.
Likewise, we have developed numerous works with bacteria of the genera Pseudomonas, Bacillus, Azotobacter and Azospirillum, evaluating the efficacy in different soils, climates and crops, achieving conclusive results: increase in the availability of phosphorus and potassium of approximately +20/30%, achieving in parallel an increase in the availability of Ca and Mg of +8/10%, together with a reduction in chlorides and boron.
The set of aspects and improvements achieved translates into a healthier plant/crop, with a greater nutritional contribution, also achieving greater resistance to diseases and higher productive yields. We are currently working with new strains of rapid implantation to colonize the soil with bacteria after disinfection to avoid possible re-infection with pathogens, as well as how developing new formulations and tests that allow us to continue at the forefront in the use of beneficial bacteria in agriculture.
If you want more information, please contact our Technical Director, Pedro Palazón by email, palazon[at]ideagro.es, or by phone at 968 118 086. Do not hesitate to ask us about it! At IDEAGRO we have a multidisciplinary team at your entire disposal.
Sources consulted:
Inorganic phosphate solubilizing bacteria isolated from soils... Leticia Andrea Fernández; Pablo Zalba; Marisa Anahí Gómez and Marcelo Antonio Sagardoy http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1850-20672005000100004
The role of phosphorus solubilization in microbial biofertilizers. Maria Teresa Fernandez, Hilda Rodriguez http://www.redalyc.org/pdf/2231/223120688005.pdf
Biofertilization: Productive aspects, consequences in the management and conservation of soil fertility. Ing. Gabriel M. Frontera http://www.fertilizando.com/articulos/Biofertilizacion.asp
Microorganisms that enhance plant growth and soil quality. Corpoica Magazine – Agricultural Science and Technology (2010) 11(2), 155-164. http://www.corpoica.org.co/sitioweb/Archivos/Revista/Microorganismos.pdf[:in]
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 generates 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 it 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 soil 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 environment.
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 significant 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 beneficial 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 Palazon, 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.[:]
English 
Spanish