Efeito de doses e épocas de aplicação de nitrogênio na biomassa e nitrogênio acumulado em cana-de-açúcar em latossolo no Estado de São Paulo
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2021-07-07
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Universidade Estadual Paulista (Unesp)
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A cana-de-açúcar é uma cultura de suma importância para economia do Brasil, crescendo anualmente a área plantada no país. O cultivo de cana requer uma alta quantidade de nutrientes, principalmente o nitrogênio, para que a planta se desenvolva adequadamente. O objetivo do trabalho foi avaliar o efeito de doses de nitrogênio e momentos de aplicação do fertilizante, na produção de matéria seca e N acumulado na biomassa da cana-de-açúcar, produtividade e ATR, em dois anos de cultivo de cana (2ª e 3ª soca), durante o ciclo da cultura. O experimento foi conduzido em uma área comercial de cana-de-açúcar localizada no Estado de São Paulo, Brasil (21 ° 22'38.48 "S, 47 ° 57'28.01" O). O experimento foi instalado em esquema fatorial 4x3, mais o tratamento controle, distribuídos em blocos ao acaso com quatro repetições. Foram realizadas duas aplicações do fertilizante nitrogenado. A primeira foi realizada logo após a colheita e a segunda aplicação foi realizado quando a cultura estava com aproximadamente 1,10 m de altura. Os tratamentos foram 4 doses de nitrogênio, 54, 109, 163 e 218 kg ha-1 de N, mais o tratamento controle (0 kg ha-1 de N) e três momentos de aplicação: 1) aplicação de todo o fertilizante na primeira aplicação; 2) aplicação do N parcelado, a primeira metade da dose na primeira aplicação e a outra metade na segunda aplicação 3) aplicação de todo fertilizante na segunda aplicação. A cultivar implantada no experimento foi a RB85-5156. Analisou-se matéria seca (MS) e N acumulado da parte aérea da cana-de-açúcar (biomassa), dividido em ponteiro e colmo, ATR e produtividade, em dois anos de cultivo (2018/2019 e 2019/2020), durante o ciclo da cana-de-açúcar. Observaram-se maiores quantidades de MS e N acumulado no ponteiro, colmo e biomassa, quando aplicado todo fertilizante logo após a colheita, no início do ciclo da cultura, antes dos 191 dias após a colheita (DAC). No entanto, após a segunda aplicação, seja todo o fertilizante ou parceladamente, foi possível observar que as quantidades de MS e N acumulado no ponteiro, colmo e biomassa foram maiores. Não foi observado diferença estatística para produtividade da cana-de-açúcar entre os tratamentos avaliados. Porém, observou-se maior quantidade de ATR, no primeiro ano agrícola, quando aplicado todo o fertilizante no momento em que a cultura estava com aproximadamente 1,10 m de altura. A quantidade de dias chuvosos, por período de amostragens da cana, foi determinante na produção de biomassa e produtividade.
Sugarcane is a crop of paramount importance for the Brazilian economy, with the planted area growing annually. Sugarcane cultivation requires a high amount of nutrients, mainly nitrogen, for the plant to develop properly. This study aimed to evaluate the effect of nitrogen rates and fertilizer application times on dry matter production and accumulated N in sugarcane biomass, yield, and total recoverable sugar (TRS) during two years of sugarcane cultivation (2nd and 3rd ratoon) in the crop cycle. The experiment was conducted in a commercial sugarcane area located in the State of São Paulo, Brazil (21°22′38.48″S, 47°57′28.01″W). The experiment was set up in a 4x3 factorial scheme plus the control treatment, distributed in randomized blocks with four replications. Two applications of nitrogen fertilizer were carried out. The first application was carried out right after harvest and the second application was performed when the crop was approximately 1.10 m high. The treatments consisted of four nitrogen rates (54, 109, 163, and 218 kg N ha−1) plus the control (0 kg N ha−1) and three application times, as follows: 1) application of all the fertilizer in the first application; 2) split N application, the first half of the rate in the first application and the other half in the second application; and 3) application of all fertilizer in the second application. The cultivar RB85-5156 was used in the experiment. Dry matter (DM) and accumulated N of the sugarcane shoot (biomass), divided into top and stalk, TRS, and yield were analyzed in two years of cultivation (2018/2019 and 2019/2020), during the sugarcane cycle. Higher amounts of DM and N accumulated in the tops, stalk, and biomass were observed after the second application of nitrogen fertilizer, when a crop was approximately 1.10 m high, a period with a high precipitation. No statistical difference was observed for sugarcane yield between the evaluated treatments. However, a higher amount of TRS was observed in the first agricultural year, when all the fertilizer was applied when the crop was approximately 1.10 m high. The number of rainy days per sugarcane sampling period was decisive for biomass production and yield.
Sugarcane is a crop of paramount importance for the Brazilian economy, with the planted area growing annually. Sugarcane cultivation requires a high amount of nutrients, mainly nitrogen, for the plant to develop properly. This study aimed to evaluate the effect of nitrogen rates and fertilizer application times on dry matter production and accumulated N in sugarcane biomass, yield, and total recoverable sugar (TRS) during two years of sugarcane cultivation (2nd and 3rd ratoon) in the crop cycle. The experiment was conducted in a commercial sugarcane area located in the State of São Paulo, Brazil (21°22′38.48″S, 47°57′28.01″W). The experiment was set up in a 4x3 factorial scheme plus the control treatment, distributed in randomized blocks with four replications. Two applications of nitrogen fertilizer were carried out. The first application was carried out right after harvest and the second application was performed when the crop was approximately 1.10 m high. The treatments consisted of four nitrogen rates (54, 109, 163, and 218 kg N ha−1) plus the control (0 kg N ha−1) and three application times, as follows: 1) application of all the fertilizer in the first application; 2) split N application, the first half of the rate in the first application and the other half in the second application; and 3) application of all fertilizer in the second application. The cultivar RB85-5156 was used in the experiment. Dry matter (DM) and accumulated N of the sugarcane shoot (biomass), divided into top and stalk, TRS, and yield were analyzed in two years of cultivation (2018/2019 and 2019/2020), during the sugarcane cycle. Higher amounts of DM and N accumulated in the tops, stalk, and biomass were observed after the second application of nitrogen fertilizer, when a crop was approximately 1.10 m high, a period with a high precipitation. No statistical difference was observed for sugarcane yield between the evaluated treatments. However, a higher amount of TRS was observed in the first agricultural year, when all the fertilizer was applied when the crop was approximately 1.10 m high. The number of rainy days per sugarcane sampling period was decisive for biomass production and yield.
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Agricultura, Ciência, Educação, Plantas análise