Microorganism groups were able to fix atmospheric nitrogen in plants, saving on fertilizers and reducing environmental impacts. Microorganism groups were able to fix atmospheric nitrogen in plants, saving on fertilizers and reducing environmental impacts. Embrapa seeks private partners to prompt technology to market Researchers from Embrapa Temperate Agriculture(RS) developed a bacterial consortium that can promote biological nitrogen fixation (BNF) in rice, a technique used in legumes to provide the plant with the nutrient present in the atmosphere. In experiments, the inoculant was able to increase the cereal yield by up to 30%. The microorganisms can turn into new bioinputs for the crop and scientists are looking for partners to bring it to the market (see table). The cultivar BRS Pampa CL, with reduced cover nitrogen fertilization (90 kg of N per hectare) and combined with two bacterial consortia, resulted in high yields in four agricultural seasons. The results obtained proved that the formulation of a peat inoculant has agronomic efficiency in the grain yield of this cultivar. High levels of relative chlorophyll content index and higher nitrogen accumulation in rice grains were also recorded as an effect of BNF. The production of dry mass of the aerial part was 33% higher compared to the cultivation made without nitrogen and without the biological nitrogen fixation bacteria. Scientists tested two groups of bacteria. The first consortium was formed by a Pseudomonas species and two of Bacillus sp. and resulted in an average rice grain yield of 10,585 kg per hectare. The other contained species of Bacillus, Aeromicrobium, and Rhizobium and it presented an average rice grain yield of 11,405 kg per hectare, equivalent to the yield with the use of complete fertilization recommended for rice (11,204 kg ha-1). "The Bacillus genre’s functionality has been demonstrated to increase the production performance of irrigated rice. In addition, bacterial consortia with different genera and species add multi-functionality for the benefit of rice plants”, declares the Embrapa researcher Maria Laura Turino Mattos, who conducted the research and is responsible for a collection with about 500 isolated microorganisms for irrigated rice in lowland environments. The problem Increasing the profitability and quality of irrigated rice grown in 1.3 million hectares at lowlands is one of the challenges of Southern Brazil. And according to Mattos, in flood-irrigated rice farming, the application of nitrogen chemical fertilizers is essential to obtain high productivity. According to her, the rational use of mineral nitrogen fertilizer is essential not only to increase recovery efficiency but also to raise crop yield and decrease the cost of production and the risks of environmental contamination. “In rice croplands, in lowland areas, only 50% of the nitrogen applied is fully harnessed by the rice plant, and this has greatly burdened the cost of each hectare of cropland. The low agronomic efficiency of nitrogen fertilization can contribute to an increase in greenhouse gas emissions,” she explains. The scientist comments that the use of high doses of nitrogen in the initial phase of rice cultivation promotes excessive growth in the plants, causing self-shading of the leaves and increasing susceptibility to fungal diseases (mainly brusone), as well as the bedding of plants, which hinders harvesting and consequently not only reduces productivity and grain quality but also increases production costs. The study of the bacterial consortia for rice Previous studies with diazotrophic endophytic bacteria, which interact positively with irrigated lowland rice genotypes, have shown potential for 20% to 30% increase in rice production. The results motivated the team to conduct a study to assess the agronomic efficiency of new diazotrophic endophytic bacteria for lowland edaphoclimatic conditions in the Brazilian state of Rio Grande do Sul (RS). Mattos points out that the study demonstrates that the new bacteria can colonize rice plants. "The predominance is colonization in the root zone, starting in the endoderm, spreading through the xylem and reaching the aerial parts, which increases the development of the plant and the production of rice grains,” she notes. The research The "good" bacteria were isolated from leaves, culms, and roots of the irrigated rice grow crop BRS Taim and endophytic diazotrophic bacteria were obtained from the culm of the irrigated rice cultivar BRS Pelotas. Another identification of the presence of these bacteria was made in the irrigated rice cultivar BRS Querência, BRS Pampa and BRS Pampeira, all from Embrapa. Each season, the treatments were assessed by determining the mass of grains and production components, with records of agronomic efficiency during four agricultural seasons: 2015/2016, 2017/2018, 2018/2019, and 2019/2020 in the edaphoclimatic conditions of the Terras Baixas Experimental Station of Embrapa Temperate Agriculture, in Pelotas, RS. “It is a robust study, as research takes years to obtain a microorganism, which requires the identification of the potential for use in agriculture, the validation of efficiency in the field, and the proof that it is not pathogenic to humans plants and that it will not negatively impact the environment,” explains the researcher Maria Laura Mattos. In addition to Mattos, the work was developed by the researchers Walkyria Bueno Scivittaro, Ricardo Alexandre Valgas, Paulo Ricardo Reis Fagundes, of Embrapa temperate agriculture; Alcido Elenor Wander and Tereza Cristina de Oliveira Borba, of Embrapa Rice and beans (GO); Itamar Soares de Melo, of Embrapa Environment (SP); and Mariangela Hungary, of Embrapa Soybean (PR). The success of BNF soybeans The study of inoculation for irrigated rice crops was inspired by the success of BNF technology with soybean cultivars, today one of the greatest examples of the application of beneficial microorganisms in agriculture. The researcher Marco Antonio Nogueira, of Embrapa Soybean (PR), reports that each ton of grain requires about 80 kg of nitrogen, which can be supplied mostly by inoculation with bacteria that settle in the root, the rhizobia (Bradyrhizobium), which obtain Nitrogen from the atmosphere and make it available for the plant, dispensing with the use of nitrogen fertilizers. "If Brazilian farmers had to supply this nitrogen through the application of fertilizers, they would have disbursed about US$17 bi in the last season. In addition, this biological process prevents millions of tons of GHG from being released into the atmosphere, which gives great sustainability to the Brazilian soybean production system”, declares Nogueira. The researcher says that, from 2013, Embrapa then began to recommend the adoption of a second type of bacteria for the inoculation of the soybean, the Azospirillum, alongside the already known rhizobia. This process is known as co-inoculation or mixed inoculation. "The research carried out by Embrapa indicated that the co-inoculation of soybean with Azospirillum resulted in average productivity gains of 16%, further increasing the benefits for the crop and the grower,” he recalls. Inoculation in Brazil The inoculant production for legumes in Brazil began in 1956, in the first industry of its kind in the country, in the municipality of Pelotas, RS. In the industry, the production of inoculants involves the multiplication of a bacterium that is highly demanding to reactors with aseptic handling and requires professionals with knowledge of microbiology, microbiological processes, and strict quality control at all stages of the process. Only organisms validated by agronomic efficiency research and authorized by the Ministry of Agriculture are used in the manufacture of inoculants by Brazilian industries. BNF Biological nitrogen fixation is included in the Low Carbon Agriculture Plan, from the Ministry of Agriculture, Livestock and Food Supply (Mapa), a set of actions to expand the adoption of several sustainable agricultural technologies to mitigate greenhouse gas emissions (GHG) and fight global warming. BNF technology can be applied in two ways: either by treating the seeds with inoculants or performing inoculation in the rice furrows. Partners to produce the new bioproduct Companies interested in bringing the new bioinputs to the market can contact Embrapa Temperate Agriculture by phone (53) 99981-3701 or https://www.embrapa.br/fale-conosco/sac. Those interested can also watch a conversation about the bioproduct that uses the Azospirillum brasiliense, developed in a partnership between Embrapa and Biotrop, as an example that rice responds to the use of microorganisms. And they can check out the broadcast Prosa Rural, with the theme "Use of inoculant in irrigated rice in the Rio Grande do Sul", with the participation of Maria Laura Mattos and the farmer Valdemiro Aguiar, from Santa Vitória do Palmar,RS.