New ZARC methodology will bring more security to rural producers

From 2021, Brazilian farmers will be able, when taking out rural insurance, to know the probability of productivity of different crops depending on the sowing date, the cultivar and the type of soil in the municipality where the crop is planted. A new Agricultural Climate Risk Zoning methodology (ZARC) is being developed by Embrapa and partners. Soybeans and corn should be the first agricultural crops to be covered with this information.

Embrapa Cerrados (DF) leads the research project “Assessment of Agroclimatic Risk and Resilience” (ARRA), which began in May last year and has the participation of 19 other Embrapa research centers. The main objectives are to develop new methodologies for assessing risks, productivity and agro-climatic resilience of agricultural production systems and to build an agronomic and agro-climatic database with the probabilities of occurrence of productivity of various agricultural crops in the country. The research adheres to the Program National Agricultural Zoning of Climate Risk, from the Ministry of Agriculture, Livestock and Supply (Map).

Project leader, researcher Fernando Macena explains that the idea is to gradually replace the current ZARC methodology, which determines sowing dates based on a water stress index, with another that works with the probability of productivity according to the sowing time, the cultivar used and the location of the crop. “We are talking about the probability of obtaining a certain yield, depending on a certain sowing date, cultivar and type of soil. In other words, if I plant soybeans between October 10th and 20th in a certain location, there is an 80% probability of producing at least 4 thousand kg/ha”, he explains. 

In Brazil, the main climatic risks that limit the productivity of agricultural crops and cause losses are, mainly, water deficit when it occurs in the most critical phases of the crop, excess rainfall, high temperatures, frost and rain at harvest time. . 

The development of the methodology takes into account climate data (solar radiation, temperature and relative humidity, wind speed and reference evapotranspiration); of the plant (cultivar, cycle, plant population); of the soil (water storage capacity and availability) and the technical itinerary of the crop (fertilization, correction, soil fertility management, among others), which are incorporated into mathematical models for analyzing climate risks. 

Part of the research project activities is based on the “yield elaboration” tool. Data on crop performance is collected in experiments that use irrigation and good management practices regarding fertilization, pest and disease control, among others. Obtained under production conditions considered ideal, these data are used to calibrate the mathematical yield models of each crop studied, thus serving as a potential productivity reference for calculating productivity probabilities based on historical climate data provided by agrometeorological stations in each Brazilian municipality.

The project, which lasts three years, includes some of the country's main agricultural crops – soybeans, corn, beans, rice, cocoa, sugar cane and wheat, in addition to brachiaria grass and cactus. Another work front is the adaptation of the methodology for Crop-Livestock Integration (ILP) and Crop-Livestock-Forest (ILPF) systems.

One of the first experiments was implemented at Embrapa Cerrados, where the behavior of soybean and corn cultivars and varieties (four of each crop) from different cycles are currently analyzed. Beans and sugar cane should be the next crops to be evaluated. “Our calibration of the model will be valid for all of Central Brazil”, says Macena.

The researcher adds that the research is connected to Embrapa's genetic improvement programs. “In the areas of validating new soybean and corn cultivars, for example, we will validate the calibration of the ZARC yield model,” he explains. In this way, new materials will be launched providing recommendations for the best planting dates based on the probability of productivity. 

Macena notes that the new methodology will bring greater security to producers, credit institutions and the government, which will strengthen ZARC's public policy with more sophisticated information. “Our expectation is to improve risk prediction technology for the main agricultural crops in Brazil, with the aim of guiding the best sowing dates in order to reduce risk for producers and losses for agents who grant credit. It is a benefit to society in general.”

About ZARC

Developed by Embrapa and partners, the method ZARC It has been applied in Brazil as a public policy since 1996, through MAPA. The ZARC indicates dates or planting/sowing periods by crop and by municipality, considering the characteristics of the climate, the type of soil and the cycle of cultivars, to prevent climatic adversities from coinciding with the most sensitive phases of the crops, minimizing agricultural losses . Technology is considered an essential tool to support decision-making for the planning and execution of agricultural activities, for public policies and, notably, agricultural security.

Climate risk agricultural zoning studies include more than 40 annual and perennial crops, in addition to zoning for the intercropping of corn with brachiaria, reaching 24 Federation Units. To access Proagro, Proagro Mais and the federal subsidy for rural insurance premiums, the producer must comply with ZARC's recommendations. Furthermore, private financial agents are already making the granting of rural credit conditional on the use of climate risk agricultural zoning.