Scientists develop technology that performs biological assessment of soil

From now on, in addition to chemical and physical analyses, rural producers and agricultural consultants will also have a new ally to assess soil health. Embrapa researchers have developed a technology that will reveal aspects related to the biological functioning of the soil that, until then, went unnoticed in fertility analyses, but which can impact the economic performance of crops and the sustainability of agroecosystems.

Called BioAS, the technology is the missing piece to better understand the productive potential of this natural resource. The statement is Ieda Mendes, researcher at Embrapa Cerrados (DF) who leads the Bioindicadores project. “Biology is the basis of soil health. Until then, we had no idea how the biological machinery of our soils was working. BioAS changes that,” he declares. 

The technology consists of the analysis of two enzymes (beta-glucosidase and arylsulfatase) that are related to the productive potential and sustainability of land use. They are associated, respectively, with the carbon and sulfur cycles and function as bioindicators of soil health. High quantities of these bioindicators indicate adequate and sustainable production systems or soil management practices. On the other hand, low values ​​serve as a warning for the farmer to reevaluate the production system and adopt good management practices.

Able to anticipate changes in the soil

One of the main advantages of the technology, according to experts, is precisely to anticipate changes, positive or negative, that are occurring in the organic matter of the soil due to the management adopted on the property. This occurs, according to the scientist, because bioindicators are more sensitive than chemical and physical indicators. Furthermore, changes in microbial communities can be detected more quickly. “BioAS technology is like a soil blood test that allows us to anticipate health problems that were previously asymptomatic”, declares Ieda Mendes.

In addition to being sensitive for detecting changes in the soil, these enzymes are related to soil functioning (nutrient cycling), are interpretable (low, medium and high levels), present coherence and reproducibility and have analytical simplicity with relatively low cost and without generate waste. From the farmer's point of view, they are related to grain yield, hence their economic importance. These enzymes are also related to soil organic matter, which denotes environmental importance.

Over the last twenty years, Embrapa researchers have dedicated themselves to selecting these bioindicators. During this work, different interpretation tables were developed that allow us to know exactly whether the level of activity of these molecules, in different types of soil, is low, medium or adequate. This was the great difference of the Bioindicadores project. 

Qualified laboratories

BioAS technology is available to Brazilian farmers through a network of laboratories enabled by Embrapa. Laboratories throughout Brazil will be able to progressively integrate into the Embrapa BioAS Network. They will be connected to Embrapa servers through a system called the BioAS Technology Soil Quality Interpretation Module, which also involves the calculation of Soil Quality Indices (IQS). 

According to the researcher Guilherme Chaer,  Embrapa Agrobiology (RJ), one of those responsible for developing this module, IQS are calculated based on chemical and biological properties together (IQSFertbio) and separately (IQSBiológico and IQSQuímico). “This is a simple and efficient way of quantifying the quality or health of a soil. In addition, we are providing scores to evaluate soil functioning in relation to cycling, storage and supply of nutrients”, he explains.

The reference parameters and indicator tables involved in BioAS technology are systematically updated, based on Embrapa's network of experiments calibrating and developing this technology. With this, laboratory customers will always have reports containing results with interpretation updated by Embrapa, harvest by harvest.

To date, nine commercial laboratories from five states in Brazil (Goiás, Mato Grosso, Minas Gerais, São Paulo and Paraná) have been trained by Embrapa to include in their routines the analyzes of the two soil enzymes that are part of the BioAS technology. “This technology is the missing tool to close the diagnostic cycle”, says Renato Alves Filho, technical manager and national director of the Soils & Plants Laboratory, in Sorriso (MT). 

According to him, with the training received by Embrapa, it was possible to reproduce the method with precise values ​​in the company's laboratory. “From now on, we will be able to evaluate the efficiency of the management adopted on the properties and, with the fertility and texture results, generate the Fertbio Soil Quality Index. This translates into more information, more assertive actions and, consequently, better results”, he emphasizes.

According to the researcher Fábio Bueno, to develop this technology, the strategy was to make it easier for both the farmer and the laboratories that will carry out BioAS. “Soil collection for bioanalysis is done in the same way as traditional analysis. The collection time is the same (after harvesting the crops) and almost all procedures are identical. The only thing that will change is that, for BioAS, the soil has to be collected in the zero to ten centimeter layer. In the laboratory, this soil will go through the same air-drying procedures used to carry out chemical analyses,” he explains. “Soil sampling for BioAS is extremely simple and practical”, emphasizes the research coordinator at BioAS. Agricultural SLC, Vitor Vargas.

Soil biology One gram of soil has around a billion bacteria and 100 fungi. These values ​​give an idea of ​​the immense genetic and metabolic diversity of soil microbial communities and, consequently, of the varied processes in which they act. With fauna and plant roots, microorganisms constitute the biological machinery of the soil. Being the living and most active part of organic matter, they can be used as bioindicators of soil health. Healthy soils are biologically active, productive and resilient, which promote the health of plants, people and animals and which preserve environmental quality, providing, among other benefits, carbon sequestration, water storage and infiltration, nutrient cycling, the bioremediation of pesticides and the mitigation of greenhouse gas emissions.

Soil biology

One gram of soil has around a billion bacteria and 100 fungi. These values ​​give an idea of ​​the immense genetic and metabolic diversity of soil microbial communities and, consequently, of the varied processes in which they act. With fauna and plant roots, microorganisms constitute the biological machinery of the soil. Being the living and most active part of organic matter, they can be used as bioindicators of soil health.

Healthy soils are biologically active, productive and resilient, which promote the health of plants, people and animals and which preserve environmental quality, providing, among other benefits, carbon sequestration, water storage and infiltration, nutrient cycling, the bioremediation of pesticides and the mitigation of greenhouse gas emissions.

Rural producer José Mário Ferreira, from Padre Bernardo (GO), believes that BioAS technology will help in the decision-making process on the property. “We need information to help with planning. We had a gap that prevented us from evaluating the productive capacity of the soil in this more integrated view. Analysis linked to soil biology came to help in this sense”, he believes. 

According to Ieda Mendes, farmers were already realizing that, often, the result of traditional analysis did not match the productivity obtained. “We had soils with similar chemical properties, within the same climatic and cultivation context, but with very different productivity levels. With bioanalysis, we were able to show why this is happening.” 

This is the case of agronomist João Batista de Almeida, consultant at the Ribeirão farm (Itiquira, MT). According to him, the farm's productivity was not being explained solely by chemical analyses. “We had areas with very low nutrient levels and good production ceilings. This was not explained chemically. With this new technology from Embrapa, today we can carry out chemical, physical and biological assessments of our soils. This is a very important parameter for us to make decisions regarding management and, thus, achieve higher productivity and reduced production costs,” he predicts.

Chemically similar but biologically distinct soils

In the soybean crop rotation experiment (RCS), conducted since 2008 by Fundação Mato Grosso, in Itiquira (MT), researchers compared the grain yield of the same soybean cultivar in monoculture, crop rotation and succession with several species vegetables, with emphasis on brachiaria. During the initial six years of the experiment there was no significant difference in grain yield. In the seventh year of the experiment (2014/2015), there was a dry spell in the soybean reproductive stage, and the soybean/brachiaria succession produced 29 bags per hectare (sc/ha) more than soybean in monoculture.

“When we analyzed what could justify this difference, we found that it was not possible to explain it solely with the results of chemical soil analysis, as the areas were similar. This clearly showed the limitation of the mineralist concept (based only on nutrient content) to determine soil fertility as a whole”, said Ieda Mendes. The analysis of soil organic matter (SOM) revealed that the area with brachiaria presented 1,5 more SOM. In turn, the BioAS results showed four times greater activity of beta-glucosidase and eight times greater activity of arylsulfatase in the same area. “In other words, the soils were chemically similar, but biologically distinct. However, with conventional analysis, this would hardly be detected”, he compares.

The researcher highlights that in the years following the experiment, the treatment with soybeans in monoculture (“sick” soil) never again managed to obtain the same yields as treatments in which soybeans are grown in rotation or succession, and until the 2018 harvest /2019, the accumulated difference was 119 sc/ha. According to Ieda, the better tolerance of the soybean/brachiaria succession to summer was related to the better physical structure of the soil in treatments with brachiaria and the enzymes function as bioindicators capable of detecting these changes. She explained that the escalation of soil improvement begins with changes in biological activity, followed by an increase in SOM, which results, over time, in greater nutrient cycling, better soil structuring and greater water retention. The scientist explains that, in the end, these factors result in greater productivity, greater efficiency of the production system and, consequently, greater profit for the producer.

“We evaluated several works in different production system experiments and the correlation between productivity and bioindicators is always high”, says Leandro Zancanaro, research director at Mato Grosso Foundation. According to him, there is no doubt that bioindicators will be valuable tools for better understanding production. 

A Agricultural SLC also participated in validating the technology. In 2018, they expanded the use of bioanalysis into commercial areas for this purpose. “The management adopted on our farms ensured high biological productivity of the soil and one of the consequences is the high average productivity of crops. In the last harvest, we harvested more than 84 bags per hectare of soybeans in an area of ​​more than seven thousand hectares. Tools like this are very much in line with SLC Agrícola’s concern for its stakeholders”, declares Vargas. “For us, concern about soil quality is fundamental, as it is the basis for all of our production”, adds the research coordinator at SLC Agrícola.

Result of 20 years of studies Studies with bioindicators in the Cerrado biome began in 1999 with the project “Characterization of biomass and microbial activity in Cerrado soils under native vegetation and under different management systems”, which was the precursor to the project “Bioindicators for assessing soil quality in different Brazilian agroecosystems”, which is finishing its third phase. These surveys involved dozens of professionals from the Embrapa, from the University of Brasília (UnB) and research foundations, such as MT Foundation.  The first phase of the Bioindicators Project began in 2004. At that time, the main objective was to identify and monitor bioindicators that showed the changes that occurred in the soil due to different management practices, indicating appropriate management to preserve or improve its quality and ensure the sustainability of agroecosystems. In this first stage, several microbiological indicators were tested, aiming to select the most appropriate ones. During Phase II, a strategy was developed that allowed the interpretation of individual enzyme values ​​to know when levels in the soil are adequate, moderate and low. In the current phase, the interpretation tables were expanded to the main soils of the Cerrado biome and the Fertbio sampling concept was developed and validated to unify the collection time and soil sample preparation procedures for soil biology and chemistry analyses. . Work was also carried out with Soil Quality Indices (IQS).  The research is supported by the National Council for Scientific and Technological Development (CNPq) and the Federal District Research Support Foundation (FAP-DF). The official launch of the technology will be held virtually on July 23rd and can be followed on Embrapa channel on Youtube.

Result of 20 years of studies

Studies with bioindicators in the Cerrado biome began in 1999 with the project “Characterization of biomass and microbial activity in Cerrado soils under native vegetation and under different management systems”, which was the precursor to the project “Bioindicators for assessing soil quality in different Brazilian agroecosystems”, which is finishing its third phase. These surveys involved dozens of professionals from the Embrapa, from the University of Brasília (UnB) and research foundations, such as MT Foundation. 

The first phase of the Bioindicators Project began in 2004. At that time, the main objective was to identify and monitor bioindicators that showed the changes that occurred in the soil due to different management practices, indicating appropriate management to preserve or improve its quality and ensure the sustainability of agroecosystems. In this first stage, several microbiological indicators were tested, aiming to select the most appropriate ones.

During Phase II, a strategy was developed that allowed the interpretation of individual enzyme values ​​to know when levels in the soil are adequate, moderate and low. In the current phase, the interpretation tables were expanded to the main soils of the Cerrado biome and the Fertbio sampling concept was developed and validated to unify the collection time and soil sample preparation procedures for soil biology and chemistry analyses. . Work was also carried out with Soil Quality Indices (IQS). 

The research is supported by the National Council for Scientific and Technological Development (CNPq) and the Federal District Research Support Foundation (FAP-DF). The official launch of the technology will be held virtually on July 23rd and can be followed on Embrapa channel on Youtube.

 Healthy soils for vibrant tropical agriculture

BioAS technology is currently formatted for annual grain and fiber crops in the Cerrado. It will soon be expanded to other regions and other crops such as sugar cane, coffee and pastures.

The researchers' expectation is that, with technology, a more comprehensive way of interpreting soil health will be inaugurated, going beyond issues of nutrient deficiency and excess. Another important aspect is that BioAS can also be used as an Agro-Environmental Indicator (IAA), forming part of a set of metrics for sustainability assessments of agricultural production systems. 

“This will certainly contribute to the greater insertion of our agriculture in the local and global bioeconomy. This is a unique initiative in the world, which could accredit Brazil as a global ambassador for soil health,” says Ieda Mendes. “For all these reasons, BioAS is considered the newest ally for the sustainability of Brazilian agriculture. By adopting management systems that promote soil health, everyone wins: the farmer, the environment and society,” he adds. 

Launch of BioAS – Embrapa Soil Biological Analysis Technology

Local News: https://youtu.be/1GnmMXrDlb8

Date: July 23

Timetable: 15h