2025-03-072025-03-072021HEINEMANN, Alexandre Bryan et al. Risco climático e período de semeadura para o arroz irrigado no Tocantins. Revista Agri-Environmental Sciences, Palmas, v. 7, n. 2, e021001, 2021. DOI: 10.36725/agries.v7i2.5262. Disponível em: https://revista.unitins.br/index.php/agri-environmental-sciences/article/view/5262. Acesso em: 24 jan. 2025.e- 2525-4804http://repositorio.bc.ufg.br//handle/ri/26919The production of irrigated rice in Brazil is divided into two environments, subtropical and tropical. The subtropical environment (mainly Rio Grande do Sul and Santa Catarina) corresponds to 80% of the total rice production in the country. In the tropical environment, rice is produced in the North, Northeast and Midwest regions. It occupies 13.2% of the total cultivated area. Despite being responsible for only 20% of the national production, the rice cultivated at tropical environment plays an important role for food security in Brazil. The objective of this study was to identify climatic risks and to define the best period with low sowing risk for irrigated rice in the state of Tocantins. Thus, the rice crop model simulation ORYZAv3 was parameterized and validated. Results showed that an increase in climatic risk from 30% (70% of success) to 20% (80% of success) reduces the sowing window for October to December. However, to achieve potential production the recommended sowing window for the irrigated rice cultivar is from October to mid-November.porAcesso Abertohttp://creativecommons.org/licenses/by-nc-nd/4.0/ArrozSemeaduraModelos de simulação de culturaRiceSowingCrop modellingArtigo10.36725/agries.v7i2.5262