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PT_BR 
Researchers from Embrapa Agropecuária Oeste (MS) validated, under real field conditions, the efficiency of the Agricultural Zoning of Climatic Risk – Management Levels (ZarcNM) methodology. The results show a linear relationship between soil management quality and productive performance of the crop. soyFor each level of improvement in management achieved by the producer, an average increase of 11.1% in the relative productivity of the crop is observed. The methodology classifies the plots (cultivation units) into four management levels – NM1 (lowest quality) to NM4 (highest quality).
The research was conducted in a long-term experiment installed 30 years ago in the municipality of Dourados (MS) and analyzed 28 consecutive soybean harvests, between 1998 and 2026. In total, more than 4,300 georeferenced points were evaluated. At these points, over the years, values of chemical analyses, soil cover, and crop productivity were recorded, which made it possible to apply the classification of management levels (ML) and relate it to soybean productivity at each point and harvest.
The study proves that soil management is important in determining the success of soybean production. Areas where conservation practices are adopted show higher productivity, cope better with drought periods, and are less vulnerable to crop loss risks, which confirms the relevance of soil conservation for the sustainability of agriculture.
Researcher Júlio Cesar Salton, from Embrapa Agropecuária Oeste, emphasizes that the way the soil is managed directly influences the ability of crops to withstand periods of water scarcity. "Well-managed soils store more water, offer better conditions for root development, and make soybean crops more resistant to climatic fluctuations," he states.
Climate risk assessment
Traditionally, Zarc considers factors such as climate, soil type, sowing time, and cultivar cycle to indicate sowing windows with the lowest risk of losses. The innovation of ZarcNM consists of adding the quality of the soil management system adopted by the farmer to this analysis. The methodology classifies the plots into four management levels, identified as NM1, NM2, NM3, and NM4.
NM1 represents lower quality systems, generally associated with conventional tillage, soybean monoculture, and gradual soil degradation. NM4, on the other hand, corresponds to the highest level, characterized by conservation practices such as no-till farming and integrated crop-livestock systems.
In practice, the higher the level of management, the greater the soil's capacity to function as a kind of natural water reservoir, reducing the effects caused by dry spells – periods without rain that occur in the middle of the rainy season, frequent in Mato Grosso do Sul.
Production models
The ZarcNM validation was performed based on three distinct agricultural production models. The first corresponded to conventional tillage, characterized by soybean monoculture and constant soil disturbance through harrowing (soil preparation that occurs with the use of disc harrows before sowing).
The second involved the no-till farming system, in which the soil remains undisturbed and different crops are rotated over the years.
The third study evaluated crop-livestock integration, a model in which soybeans are alternated with pastures, promoting improvements in the physical, chemical, and biological conditions of the soil.
The researchers analyzed indicators related to chemical attributes, soil cover, crop diversity, and time without soil disturbance.
Advances in management, increased productivity.
Research shows that for each level of quality in management achieved by the producer – for example, transitioning from NM2 to NM3 – there is an average increase of 11.1% in relative productivity. The averages obtained during the 28 harvests were significant, with relative productivity of 44.0% in NM1; 55.1% in NM2; 66.2% in NM3; and 77.2% in NM4.
Throughout the evaluated period, productivity varied considerably, as was the case in the Dourados region, with values mostly ranging between two and approximately 90 sacks per hectare, resulting from the interaction between rainfall, the timing and duration of dry spells, and soil management practices.
In the most favorable years, some areas exceeded 80 sacks per hectare. In contrast, during extreme weather events, systems managed under conventional tillage even recorded total crop loss.
"The study proves that investing in quality management means reducing risks, increasing productive stability, and preparing the system to face adverse weather events," Salton points out.
Six indicators
To classify each area between levels NM1 and NM4, ZarcNM uses six indicators considered essential for evaluating the quality of management: the time without soil disturbance, the amount of vegetation cover existing before sowing, the base saturation in the surface layer, the calcium content and aluminum saturation in the deeper layers, and the diversity of crops in the last three agricultural years.
According to the researchers, monoculture-based systems tend to remain at lower levels, while areas managed with crop rotation and crop-livestock integration more easily reach higher levels.
One of the aspects highlighted by the research was the importance of crop diversity. The indicator considers the history of the last three agricultural years, assessing whether there has been an alternation of plant species or a predominance of monoculture. “This diversity favors the improvement of the physical structure of the soil, increases biological activity, expands water infiltration, and contributes to the formation of a more favorable environment for root growth. As a consequence, plants are able to explore deeper layers of the soil profile, increasing their capacity to withstand periods of drought,” explains Salton.
The results show that the greatest benefits of conservation management appear in years of moderate water deficit. Under these conditions, areas classified as NM3 and NM4 maintained significantly higher levels of productivity compared to conventional systems.
Even so, the study highlights that there are limits imposed by climatic conditions. “In the south-central region of Mato Grosso do Sul, the occurrence of frequent dry spells and the low water retention capacity of the soils have historically compromised crop yields, as in the 2003/04 harvest, when rainfall was quite low (between 150 mm and 200 mm), and 2020/21, in which losses were significant, with the lowest rainfall volume in the entire series of records (less than 100 mm),” reports researcher Carlos Ricardo Fietz, based on historical data from Guia Clima, an agroclimatic monitoring system of Embrapa Agropecuária Oeste.
While areas managed under conventional methods reached zero production in some cases, conservation systems managed to partially reduce losses. "Proper management doesn't completely eliminate the effects of extreme drought, but it significantly increases the crop's ability to cope with moderate water deficits and minimizes the risk of severe losses," emphasizes Salton.
Impacts may extend to rural credit and insurance.
Beyond the agronomic benefits, the validation of ZarcNM can support technical decisions and public policies aimed at the agricultural sector, as the methodology allows for a more precise identification of the climate risk associated with management quality. “This contributes to fairer access to agricultural insurance by considering management attributes beyond soil texture. By investing in soil conservation, producers have a lower probability of losses due to drought,” says researcher Michely Tomazi.
According to 2022 data from the Ministry of Agriculture, Livestock and Supply (Mapa), 80.5% of the losses registered in Mato Grosso do Sul were related to water deficiency. "The study demonstrates that practices such as no-till farming and crop-livestock integration are no longer just technical recommendations, but are becoming concrete instruments to increase the productive, economic and environmental security of soybeans in Mato Grosso do Sul and other producing regions of the country," concludes Salton.
Research team
The validation of the Agricultural Zoning of Climatic Risk – Management Levels (ZarcNM) in the experiment in Dourados (MS) was conducted by researchers Júlio Cesar Salton, Michely Tomazi, Éder Comunello and Carlos Ricardo Fietz, from Embrapa Agropecuária Oeste. Also participating were scholarship recipients Rafael Silva Ferreira and Fabrícia da Silva Ramos, from the agreement between the Foundation for Research and Development Support (Faped), Itaipu Binacional and the Embrapa research center.
Good management leads to higher insurance subsidies.
ZarcNM is available, on an experimental basis, for the soybean crop in the states of the Southern region and in the state of Mato Grosso do Sul; and, for the second corn crop, in Paraná and Mato Grosso do Sul. Farmers who participate will receive differentiated subsidies when contracting agricultural insurance through the Rural Insurance Premium Subsidy Program (PSR).
In the soybean harvest, plots classified in NM4 will receive a subsidy of 40%, while in NM3 the subsidy will be 35% and in NM2, 30%. Plots in NM1 will receive the program's standard subsidy of 20%.
For second-crop corn, the subsidy will be 50% for management levels 3 and 4, 45% for NM2, and 40% for NM1.
Farmers who wish to participate should seek out accredited operators, who can be found on the relevant webpage. The first step is to conduct a soil analysis.
The data will be entered by the laboratory into the Management Level Information System (SiNM). Subsequently, the contract operator, which may be an insurance company, bank, or cooperative, will enter the producer and farm data and activate a geoprocessing operator to collect the remaining information. Based on the data, the system calculates and classifies the management level.
This is the second year that ZarcNM is being tested. In the 2025/2026 crop season, the pilot experiment was conducted only with soybean crops in Paraná. The expectation is that the initiative will gradually expand to other regions and other crops.
