In nature, only legumes use atmospheric nitrogen N2 with the help of symbiotic bacteria of the Rhizobium genus. In the case of Azotobacter bacteria, the process of binding N2 to ammonia (NH3) available for plants takes place with the participation of the enzyme nitrogenase. A specially selected strain of these bacteria – Azotobacter salinestris CECT 9690 – is available to farmers in the form of Rhizosum N plus, a product that improves soil properties. Additionally, the preparation contains manganese and iron and 80% organic matter.
The introduction of Rhizosum N plus into autumn fertilization of rapeseed, especially in warm conditions and increasingly longer autumn vegetation periods, allows for:
- improving the nitrogen supply of plants even with delayed sowing,
- increasing the nitrogen pool in the soil for the autumn-winter period and for the spring start of vegetation,
- reducing fertilization costs,
- obtaining high yields,
- increasing the profitability of cultivation.
In 3 ways
Rhizosum N Plus is a biofertilizer with a triple mode of action. Azotobacter salinestris CECT 9690 bacteria provide plants with nitrogen:
- as foliar endophytes (colonizing the surface and internal tissues of leaves),
- as root endophytes (colonizing the surface and internal tissues of the root),
- in the rhizosphere (the area of soil around the roots).
This unique triple mode of action makes Rhizosum N plus more efficient, flexible and versatile compared to other microbial-based biofertilizers that are intended exclusively for foliar application.
The relationship between Azotobacter salinestris and crop plants is a tightly regulated balance that allows the plants to be nourished with nitrogen and the strain to survive. The nitrogen fixation system of Azotobacter salinestris is activated immediately after the bacteria reach plant tissues. There, the enzyme nitrogenase can fix nitrogen to ammonia (NH3) using plant secretions (a source of carbon and microelements), and the fixed form of ammonium nitrogen can be taken up by the plant directly by glutamine synthetase and used for protein synthesis. When plants no longer need more ammonia for protein biosynthesis, the plant's glutamine synthetase metabolic pathway is blocked and the bound ammonia begins to accumulate in the surroundings of Azotobacter salinestris .
This sustained accumulation of the ammonium NH4 ion inactivates the nitrogenase enzyme because it is not necessary to synthesize more NH4. When plants need nitrogen again and ammonia uptake begins, Azotobacter salinestris nitrogenase is activated again to fix N and provide ammonium ion (NH4) for the biosynthesis of plant proteins. This mechanism ensures full safety of using Rhizosum N plus in autumn in agricultural crops, such as winter rapeseed, because it ensures a good supply of nitrogen to plants at an optimal level and the accumulation of reserves of this ingredient in the soil and plants for the start of spring vegetation.
Components of effectiveness
Why is the Azotobacter salinestris CECT 9690 bacterial strain so effective? Because:
- works immediately after application – within just a few hours the plants and rhizosphere are penetrated and colonized, a biofilm is produced and nitrogen fixation begins and its supply to the plants,
- has a high ability to adapt to high salinity (NaCl), which is important in sites where higher doses of fertilizers were used, especially during periods of water deficit,
- works in a wide pH range – 5.0–9.0 (optimal is 5.5–8.5),
- shows high optimal tolerance to calcium carbonate in water used for spraying – up to 20 g/l (hard water contains 300 mg CaCO3/l),
- is characterized by a wide optimal temperature range (4-45 degrees C) in which it is active and binds nitrogen from the air,
- affects the synthesis of growth hormones, especially IAA auxin, stimulating plant growth,
- reduces ethylene levels and, as a result, plant stress,
- shows good compatibility with the most commonly used agrochemicals and fertilizers; note – it must not be used with copper fungicides.
We remind you that the relationship between Azotobacter salinestris and crop plants is a tightly regulated balance that allows the plants to be nourished with nitrogen and the strain to survive.
It's not everything. It is worth knowing that the effectiveness of Rhizosum N plus in your own field can be checked thanks to the "N-tester" service offered by Agrosimex. The effects of applying the preparation are not always visible to the naked eye. However, the undeniable proof of the effectiveness of Rhizosum N plus is the level of nitrate content in plant juice. Their concentration is measured in the appropriate phase of crop development using a specialized LAQUAtwin NO3 device.
Do you want to have irrefutable proof of the validity of using Rhizosum N plus? Contact Agrosimex – go to agrosimex.pl
Prepared by: Krzysztof Zachaj, Iwona Polewska-Jankowiak