Desempenho agronômico do milho em diferentes cenários climáticos no Centro-Oeste do Brasil

Abstract

R E S U M OEste estudo propôs analisar o desempenho agronômico das 1 a e 2 a safras do milho cultivado no Centro-Oeste do Brasil, em diferentes cenários climáticos. Dados climáticos de cinco municípios localizados nas principais regiões produtoras de milho do Mato Grosso, Mato Grosso do Sul e de Goiás, foram utilizados no software Aquacrop 4.0 para determinar a duração do ciclo, produtividade, eficiência do uso da água, requerimento de irrigação líquida e o índice de colheita ajustado em diferentes cenários climáticos, baseados nos valores do percentil 25 e 75% da distribuição do 'ensemble' entre os modelos utilizados para gerar o cenário RCP 4.5 em curto prazo (2016-2035) e médio prazo (2046-2065) do Painel Intergovernamental sobre Mudança Climática. No contexto geral a primeira safra do milho terá redução na duração do ciclo mas não sofrerá com estresse hídrico no Centro-Oeste do Brasil. A produtividade e o requerimento de irrigação líquida do milho safrinha tendem a diminuir quanto maior for a redução na duração do ciclo da cultura. Agronomic performance of maize in different climatic scenarios in the Central West of Brazil A B S T R A C TThis study aimed to analyse the agronomic performance of 1 st and 2 nd season of maize grown in the Central West part of Brazil in different climatic scenarios. Climatic data from five cities located in major maize producing regions of Mato Grosso, Mato Grosso do Sul and Goiás were used in Aquacrop 4.0 software to determine the duration of the cycle, yield, water use efficiency, net irrigation requirement and harvest index adjusted for different climatic scenarios, based on the percentile of 25 and 75% of the distribution of 'ensemble' between the models used to generate the scenario RCP 4.5 in the near term (2016)(2017)(2018)(2019)(2020)(2021)(2022)(2023)(2024)(2025)(2026)(2027)(2028)(2029)(2030)(2031)(2032)(2033)(2034)(2035) and medium term (2046)(2047)(2048)(2049)(2050)(2051)(2052)(2053)(2054)(2055)(2056)(2057)(2058)(2059)(2060)(2061)(2062)(2063)(2064)(2065) of the Intergovernmental Panel on Climate Change. In a general context, the first season of maize will have reduction in duration of the cycle and will not suffer from water stress in the Central West of Brazil. The yield and net irrigation requirement of maize in second season should decrease, the greater the reduction in the duration of the crop cycle. Palavras-chave:Aquacrop produtividade irrigação índice de colheita fenologia Key words: Aquacrop yield irrigation harvest index phenology

Production components and water use efficiency of corn under irrigation depths

“…The authors justified the gain in WUE because the cultivar had been improved for adaptation in semiarid conditions. However, the WUE values found in this study are similar to those reported by Minuzzi and Lopes (2015), who estimated the WUE values of corn in different climate scenarios in the Midwest of Brazil and found for the current conditions, values of 2.8 kg m -3 (Catalão -GO), 2.61 kgm -3 (Rio Verde -GO), 2.99 kg m -3 (Ponta Porã -MS), 2.91 kg m -3 (Invinhema -MS), and 2.43 kg m -3 (Diamantino -MT).…”

“…The larger depths has produced values greater than the average productivity of China (5,560 kg ha -1 ), although below the average yield of the United States, of 9,660 kg ha -1 (Ribeiro et al, 2015). Minuzzi and Lopes (2015) reported that climate is the main factor related to the production of corn. Thus, the more pronounced responses in the production components occurred in the second experimental period (E 2 ) are associated with the specific climatic variables, especially the low rainfall (78.0% lower than E 1 ), the global radiation (Rg), photosynthetically active radiation (PAR), and radiation balance (Rn), which had increases of 21.5%, 21.5% and 21.4%, respectively.…”

“…The low productivity occurred in plants in E 2 , irrigated with smaller depths, is related to the lower availability of water in the soil and consequent hydric stress. Usually, the water deficit causes reduction of the photosynthetic apparatus, CO 2 assimilation, and biomass allocation, stimulating increased accumulation of soluble sugars in the leaves and a decrease in the amount of starch (Costa et al, 2008;Minuzzi and Lopes, 2015). Melo et al (2010) reported that if water deficit occurs in the critical period, the recovery of the productive capacity of the culture will not be satisfactory and the final production will be severely reduced.…”

The sowing density on oat productivity indicators

“…Duarte et al (2013) considered the harvest index an identification component of peanut genotypes tolerant to water stress. In corn cultivation, the harvest index was used in the identification of agronomic performance to different climate scenarios in Central-West of Brazil (Minuzzi and Lopes, 2015). Fageria et al (2007) commentedon the necessity of analysis of the harvest index in studies with rice, because it is closely associated with the increase of the grain productivity.…”

Elementos meteorológicos sobre características morfológicas e produtivas do milho em diferentes épocas de semeadura

“…As condições térmicas influenciam sobre os mais diversos processos vitais das plantas, como a germinação, o desenvolvimento fenológico e o crescimento da planta como um todo (Minuzzi & Lopes, 2015).…”