Short Description of the Technology

The technology of reducing NH3 and GHG emissions through nature-based technologies is based on the development of biocomponents, composts, biofertilizers, etc., the use of which in agriculture will contribute to reducing of GHG and NH3 emissions.

Four composts enriched with consortia of beneficial microorganisms (INHORT) have been developed: compost based on brown coal and whey, compost based on brown coal and Vinassa, lignite-based soil conditioner for fruit plants, bacterial and mycorrhizal biofertilizer, and their technical descriptions. Consortia for nutrient recovery (N, P, K, Fe, other micronutrients), containing the following strains were developed: Bacillus spp., Streptomyces sp., Pantoea spp. The research results obtained so far indicate that the use of composts and consortia of beneficial microorganisms in the cultivation of fruit and vegetable plants has a positive effect on the growth, yield and the presence of groups of microorganisms in plant roots and soil. The use of these results will support the development of the market for bioproducts such as composts and the improvement of the quality of arable soils.

The Bacillus velezensis SQR9 strain, also used in this technology (NAU) has the ability to reduce nitrous oxide (N₂O) emissions from the soil. The plant-growth-promoting rhizobacterium (PGPR) strain, Bacillus velezensis SQR9, is a Gram-positive bacterium deposited at the China General Microbiological Culture Collection Center (CGMCC, Beijing, China) on February 27, 2012, under the deposit number CGMCC 5808. Laboratory culture and pot experiments demonstrated that the N₂O emission reduction capability of SQR9 is dose-dependent, with higher inoculation concentrations resulting in stronger mitigation effects. The strain achieves N₂O reduction by enhancing the enzymatic activity of N₂O reductase, thereby accelerating the conversion of N₂O to N₂. Building on these laboratory findings, we promoted the field application of SQR9 bio-organic fertilizer and observed that it effectively increased vegetable yields by alleviating plant wilt incidence and reduced soil N₂O emissions by 38% in a rotation system. The Bacillus velezensis SQR9 can be applied to vegetable cultivation fields to mitigate soil N₂O emissions.

Another aspect of research on reducing greenhouse gas emissions from soil is the development (UNITO) of technology for recovering nitrogen (N) and phosphorus (P) from biomass waste and balancing nutrients in fertiliser products. The aims to implement the process of anaerobic digestion, capable of converting manure and slurry into biogas, a green energy source, and digestate, a byproduct rich in plant nutrients. This process focuses on the precipitation of struvite, a natural mineral with composition NH₄MgPO₄·6H₂O, which can be recovered from the liquid fraction of the digestate and used as slow-release fertilizer. This is an important element of the ECONUTRI project, embracing a comprehensive strategy focused on nutrient recycling, precision fertilization, and nature-based solutions, all aimed at enhancing nutrient use efficiency while minimizing losses.

Another agricultural ammonia emission reduction technology (CAU) is to optimize and improve urea fertilizer products by adding additives such as urease inhibitors, nitrification inhibitors or humic acid, so as to achieve a synergistic emission reduction of ammonia (NH₃) and nitrous oxide (N₂O) in farmland, and improve crop yield and nitrogen use efficiency at the same time.

 

Innovative Features

In recent years, chemical agents such as biochar and nitrification inhibitors have been extensively reported as effective strategies for reducing soil N₂O emissions. These technologies enhance nitrogen fertilizer use efficiency, reduce nitrate leaching, and suppress N₂O release. However, their widespread adoption is hindered by high costs, inconsistent efficacy, and potential environmental risks. Plant rhizosphere probiotics are a class of beneficial microorganisms capable of colonizing plant root systems.  Significant advancements have been made by researchers globally in understanding rhizosphere probiotics, revealing their mechanisms of action, such as nutrient solubilization, phytohormone secretion, and emission of bioactive volatiles to stimulate plant development. These probiotics not only boost crop yields but also mitigate nitrogen loss and improve nitrogen use efficiency. Specifically, rhizosphere probiotics enhance crop nitrogen uptake and utilization, reduce soil mineral nitrogen accumulation, and interact synergistically or antagonistically with nitrogen-cycling functional microbes to curtail N₂O production.

The newly developed consortia (INHORT) enable the reduction of N and P losses in the soil by accelerating composting and increasing the bioavailability of nutrients. The use of composts improves the uptake of nutrients from the soil by plants by 20%, reduces the dose of traditional fertilizers by 40% and stimulates the development of the root system.  The new technology reduces energy consumption and greenhouse gas emissions by the fertilizer industry. The technology contributes to better uptake of nutrients from the soil by plants, which reduces the loss of nitrogen and phosphorus in the soil.

Also, the introduction of precipitation of struvite after anaerobic digestion (UNITO) will not only enable the recovery of P and N in the form of marketable product but will also help balance the nutrient composition in the liquid and solid fractions of the digestate, which can be applied as fertilizers. When the digestate is separated into solid and liquid fraction, N tends to concentrate in the liquid and P to accumulate in the solid, leading to an unbalance N:P ratio in the final products. Various pre-treatments can be applied to the starting substrate before anaerobic digestion, both to enhance biogas production and to solubilize P, facilitating its recovery from the digestate liquid fraction in the form of struvite. In this project, both enzymatic (using phytase, phosphatase and USC4, a mixture of cellulase, hemicelluloses and pectinases) and physical (hydrodynamic cavitation) treatments are applied and evaluated for their effectiveness.

The effect of farmland ammonia emission reduction technology at regional scale is not stable, and the relationship between ammonia (NH₃) volatilization and nitrous oxide (N₂O) emission in farmland is comprehensively evaluated to further optimize the technical details and implementation plan.

 

 

Type of Contribution

Newly developed microbial consortia and composts influence the reduction of N and P losses in the soil by accelerating composting and increasing the bioavailability of nutrients. This management method contributes to increasing the humus content in the soil and increasing the number and biodiversity of microorganisms in orchards and agricultural soils.These are the main factors leading to increased soil fertility and productivity.

The plant rhizosphere-derived probiotic bacterium Bacillus velezensis SQR9, originating from the plant rhizosphere, colonizes and functions within the rhizosphere to modify soil nitrogen transformation processes. It significantly enhances the soil N₂O reduction rate, thereby reducing the soil N₂O emission. Furthermore, a significant positive correlation exists between its inoculation concentration and the magnitude of soil N₂O emission mitigation. The Bacillus velezensis SQR9 can be applied to vegetable cultivation fields to mitigate soil N₂O emissions.

The use of innovative fertilizer products (enhanced nitrogen fertilizer with urease, nitrification inhibitor or humic acid, etc.) instead of traditional urea fertilizer to provide nitrogen nutrients for crops, can also promote the growth of crop roots, so that can ensure or even improve crop yield, and greatly reduce the ammonia (NH₃) and nitrous oxide (N₂O) emissions generated by traditional nitrogen fertilizer application. It can effectively solve the problem of excessive ammonia and greenhouse gas emissions in the agricultural field.

The technology for recovering nitrogen (N) and phosphorus (P) from biomass waste and balancing nutrients in fertiliser products will contribute to N and P recycling from a widely available organic waste, and to reducing the losses of these nutrients in the environment.

 

Benefits for farmers, the industry, and the environment

Microbiological plant cultivation technologies have been developed, using innovative composts containing selected strains of beneficial bacteria, stimulating growth and yield of strawberry, cucumber and apple trees and increasing the absorption of nitrogen, potassium, phosphorus and other macro- and microelements by plants. Increasing the humus content and the potential of beneficial soil microorganisms through the application of newly developed composts can ensure optimal transformation of organic matter in soils with a focus on reducing greenhouse gas emissions and increasing plant growth and yield. The use of composts will allow to reduce mineral fertilization by up to 30%, which will contribute to the protection of the natural environment. Therefore, the results regarding the effects of using newly developed composts obtained as part of the project will constitute an important alternative to the development of the bioproducts market in the world.

The main goal of the innovative fertilizer is to inhibit the conversion of nitrogen into greenhouse gases (such as nitrous oxide) and ammonia through urease inhibitors and nitrification inhibitors, thereby inhibiting the environmental impact of nitrogen fertilizer application. In addition, the economic sustainability of growers is supported by optimizing fertilizer products to improve crop yield and nitrogen use efficiency. The rational use of nitrogen fertilizer will also save energy in the fertilizer industry, thus helping to reduce ammonia and greenhouse gas emissions.

Another aspect is plant probiotics. As environmentally sustainable alternatives to conventional emission reduction techniques reliably colonize the rhizosphere offer multifaceted benefits. They enable simultaneous achievement of strategic objectives: increasing yield per unit area, improving soil structure, fostering resilient soil microbiomes, mitigating agricultural N₂O emissions, reducing total agricultural greenhouse gas output, and advancing sustainable agricultural practices. This integrated approach aligns with global goals for climate-smart agriculture and ecological sustainability.

Another important element is the technology aimed at producing organic fertilizers derived from the liquid and solid fraction of the digestate with an optimized N:P ratio tailored to match the crop nutritional requirements. Excess nutrients will be recovered and used to produce struvite, a high-quality mineral fertilizer. This will benefit both industrial partners and farmers and will contribute to the protection of the environment.

 

All of the above-mentioned solutions have a positive impact on the natural environment, increase soil microbial diversity and bring benefits to society. They are profitable for biofertilizer manufacturers and farmers.