Agricultural Climate Risk Zoning for irrigated rice is updated for Santa Catarina and part of Paraná

Ordinances 30 to 06 were published this Thursday (244/246), which define the new Agricultural Climate Risk Zoning (ZARC) for irrigated rice cultivation in the subtropical region, in Paraná, Rio Grande do Sul and Santa Catarina.

The study, carried out by Embrapa Clima Temperado (Pelotas, RS), in collaboration with the Agricultural Research and Rural Extension Company of Santa Catarina (Epagri), identifies risk areas and defines periods of low climate risk for the implementation and production of irrigated rice. , in order to reduce losses, obtain greater income and, thus, serve as a basis for granting credit and rural insurance. In Santa Catarina and part of Paraná, the study was updated and validated in 2022.

The document, therefore, indicates the sowing periods and favorable municipalities for the cultivation of irrigated rice based on three levels of climate risk: 20%, 30% and 40%. Municipalities that presented climatic conditions within the established criteria were considered suitable for cultivating irrigated rice - with a possibility of success of 80%, 70% and 60%, respectively - in at least 20% of their area.

Results

The results are presented in tables of risk classes by municipality, soil, cycle and tenth of the year, made available by the Risk Management Department of the Ministry of Agriculture, Livestock and Supply (Deger/Mapa). Access can be done on the Indicator Panel, on the Zarc Ordinances by state or on the Zarc Plantio Certo app, available for devices with Android and IOS operating systems.

Method and new evaluation criteria

In terms of database, the study uses historical series obtained from networks of terrestrial, meteorological and pluviometric stations maintained by state and national public institutions or companies. The information regarding cultivars, made available by the institutions responsible for the materials, was grouped into three groups, according to the average duration of the cycle, from sowing to maturation, and the duration of the phases of interest for risk assessment.

Regarding the assessment of thermal conditions, the document incorporates new criteria focusing on the specificities of these states, differentiating itself from the Zarc carried out for irrigated rice cultivation in Rio Grande do Sul in 2018. Now, the risk of cold is also considered ( three consecutive days with a minimum air temperature less than or equal to 15º C in pre-flowering); risk of excessive heat (three consecutive days with a maximum air temperature greater than or equal to 35º C during flowering); and risk of frost.

According to Embrapa Climate Temperado researcher and technical responsible for the work, Silvio Steinmetz, the first two criteria were used to define the sowing periods in traditional cultivation areas, and the risk of frost to delimit the sowing periods in non-traditional areas of cultivation. cultivation, such as those located in areas of higher altitude. “These choices were made because these temperatures are occurring frequently, due to the increase in heat wave and cold wave events,” he explains.

According to the document, temperature is one of the most important climatic elements for the growth, development and productivity of rice. And identifying the ideal sowing time is a management practice that stands out for reducing climate risk because it increases the chances of critical crop phases bypassing adverse meteorological elements and/or coinciding with favorable ones.

Regional differences

According to the Embrapa Digital Agriculture researcher responsible for the agrometeorology and geoprocessing part of the zoning, Ivan de Almeida, the irrigated rice production system in Santa Catarina and the coast of Paraná differs due to the use of pre-germinated sowing. In Rio Grande do Sul, sowing predominates so that germination occurs inside the soil. Only after emergence and when the seedling has four leaves, irrigation begins by maintaining a level of water.

“In Santa Catarina, 83 irrigating municipalities are directly impacted by this technology. In Paraná, this result has repercussions for the entire area considered subtropical, with emphasis on the municipalities of the Regional Center of Paranaguá, as the rest of the state, including the largest irrigated rice producing region, located in the northwest region, already has another Zarc for tropical regions”, he says.

In productive terms, according to data from the Brazilian Institute of Geography and Statistics (IBGE), around 82% of flood-irrigated rice produced in Brazil comes from the subtropical region. The state of Rio Grande do Sul is responsible for 70,1% of this amount, while Santa Catarina represents 10,2% and Paraná 1,3%.

Different zonings for irrigated rice

Given the specificities of cultivation, there are different climatic risk zones for irrigated rice. The new study updates the document prepared for the 2011 harvest, in the case of Santa Catarina. In relation to Paraná, two different studies are needed to consider different climatic situations: tropical, warmer, and subtropical, colder. The recently published Zarc encompasses the subtropical region of Paraná. The tropical region is already covered by Zarc prepared in 2020 by Embrapa Arroz e Feijão (Santo Antônio de Goiás, GO) for culture with a focus on the rest of the country.

Benefits

According to Mapa, farmers who follow the recommendations are less subject to climate risks and can be covered by the Agricultural Activity Guarantee Program (Proagro) and the Rural Insurance Premium Subsidy Program (PSR). Many financial agents only allow access to rural credit for crops in zoned areas and for planting cultivars indicated in zoning ordinances.

Study development

The Zarc study of irrigated rice comprised four phases. The last one was carried out, through meetings for discussion, improvement and validation of results. The most recent meeting, which resulted in the conclusion of the work, was held online, on May 31st, and was attended by around 25 partners, including technicians from research, extension and teaching institutions; in addition to representatives of cooperatives from Santa Catarina and Paraná.

The researcher at Epagri's Environmental Resources and Hydrometeorology Information Center (Ciram), Cristina Pandolfo, highlights the importance of Epagri's collaboration in analyzing climate risk and validating the results in Santa Catarina. “The agro-climatic parameters for preparing Zarc and the planting windows were adjusted based on local knowledge, in order to enhance productivity and reduce climate risks in Santa Catarina”, she details.

This work was carried out together with researchers Marcos do Vale, from Epagri's Itajaí Experimental Station, and Glaucia Padrão, from the Center for Socioeconomics and Agricultural Planning (Cepa), also from Epagri; in addition to extension agents representing rice producing regions in the state.

In Paraná, there was participation from several representations, including before the validation meeting, especially from the Regional Center of Paranaguá, such as the regional head of the State Department of Agriculture and Supply (SEAB), Maurício Lunardon; and the regional coordinator and agronomist of the Institute for Rural Development of Paraná (IDR-Paraná), Marcos Oliveira and Sebastião Bellettini, respectively.