Rizosphere: What is it, what is it for, composition and importance

The rhizosphereconsidered as the largest terrestrial ecosystem, is the part of the ground near the roots of the plant, which extends specifically between 1 and 3 mm from the surface of the roots inside the ground.

In this edaphic region The roots of the plants with the ground and their microorganisms interactwhich consequently reports benefits for plants, improves soil fertility and favors the degradation of toxic chemicals. It is an association known as Rizocenosiswhich allows food to obtain food, as in mycorrhiza Azospirillum, Pegotobacter and Bacillus (Plant growth promoters) in grass roots and Beijerinckia in roots of the sugarcane.

The scientific community distinguishes 3 different parts that constitute the rhizosphere:

• The endorizosphere or internal curl It includes the root cortex (tissue between endodermis and epidermis) invaded by microorganisms.
• He Rizopla or rizoplana It is formed by the surface of the root and the microorganisms in it.
• The ECTORIZOSFERA, EXORRIZOSFERA, RIZospheric soil or external curly It is the soil that is in close contact with the surface of the root of the plants.

In general terms, we can say that Rizosphere composition It is: soil, water, radical depositions (exudate and mucilage) and microbiota (bacteria, fungi, algae).

On the one hand, the soil acts as physical support and provides food to plants. Its physical-chemical properties determine the presence and distribution of microorganisms, while their conservation depends on these. We can highlight The pH as an abiotic factor that conditions and characterizes the Frhizospheresince changes in their value can lead to the inactivation of the enzymes present in microorganisms and disturb the fixation of nutritious minerals. In this region, pH values ​​are lower or more acidic compared to the rest of the soil, which is due to the cation exchange and the production of organic acids.

On the other hand, The water which is an essential resource for life, plays a very important role in rhizospheric interactions. Its availability is directly related to the porosity of the soil and, its potential to some extent is controlled by the microbiota. In fact, Microorganisms improve aeration of soil and the infiltration capacity, thus favoring the maintenance of the water film in the rhizosphere.

In connection with Radical depositionsplants release through their radical exudates photosynthetic products (sugars, amino acids, vitamins, organic acids, hormones) that if they are of low molecular weight can favor the diversity and the microbe growth of the rhizosphere. These organic compounds attract microorganisms to the surface of the roots, constituting for them a very important source of food and energy. One of these exudates is the mucigel, which is a gelatinous material that covers the surface of the roots of the plants, formed by: plant mucilages, bacterial cells, polysaccharides, mineral colloids and organic matter of the soil.

Finally, The microorganisms that inhabit the rhizosphere (Bacteria, fungi, protozoa and nematodes), mostly report benefits. The Rizosphere or rizobacteria bacteria They are responsible for decomposing radical exudations and plant waste. Fungi also highlights, which establish a symbiosis relationship with the roots, known as Mycorrhizasince, like bacteria, they are able to degrade or mineralize toxic and harmful substances in a process called detoxification. In this other article we tell you more about what mycorrizas and their types are.

The Importance of rhizosphere It resides in the interactions that take place between the plants and the microbiota of the ground. Because? Because in line with the above in previous sections:

• Through rhizosphere, plants take nutrients. The same that happens with water and carbon that need bacteria, fungi, insects, worms and protozoa to survive.
• The microflora of the rhizosphere protects the root against pathogens, against diseases and produces substances that stimulate plant growth, such as indolylet acid, gibelins and cytocinins.
• The biological fixation of nitrogen (FBN) occurs, that is, microorganisms provide nitrogen compounds (ammonium and nitrate) assimilable, which manufacture from the atmospheric nitrogen of the soil (N2).

It is well known that nitrogen is a limiting factor for plants because, despite its abundance in the atmosphere (it represents approximately 80% of its composition), they cannot take advantage of it in the molecular form in which it is found (N2). This situation has caused the massive use of chemical fertilizers to increase crop productivity. Consequently, important contamination processes that reduce soil fertility and the quality of edaphic and water resources have been triggered in the natural environment. One way to avoid this is to make visible the fixing capacity possessed by the microorganisms of the rhizospherewhich can satisfy the Plant nitrogen demandby using Biofertilizantes.

If you want to read more articles similar to Rizosphere: What is it, what is it for, composition and importancewe recommend that you enter our category of ecosystems.