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Abstract(s)
O trabalho experimental foi realizado na Quinta do Poulão em Bragança, NE Portugal nos anos de
2019 e 2020. Os objetivos foram verificar a capacidade da aveia em utilizar o nitrogênio (N)
residual da cultura do milho cultivado na estação anterior e o N residual no solo no fim do verão
(depois da coleta do milho) e na primavera (depois da coleta da aveia). O experimento foi
conduzido em delineamento experimental completamente casualizado com 10 tratamentos
fertilizantes e três repetições. Usaram-se quatro doses de N aplicado na forma de nitrato de amônio
em duas aplicações (fundo + cobertura). As doses foram 0 (0+0), 50 (25+25), 100 (50+50) e 200
(100+100) kg N ha-1. Usou-se um fertilizante de libertação controlada e um fertilizante estabilizado
com um inibidor na nitrificação, ambos em duas doses aplicadas em fundo (100 e 200 kg N ha-1).
Usou-se estrume em dose equivalente a 100 kg N ha-1 aplicado em fundo e outro tratamento similar,
mas reforçado com 100 kg N ha-1 aplicado em cobertura na forma de nitrato de amônio. Os
fertilizantes referidos foram aplicados na cultura do milho em maio de 2019. A aveia não foi
fertilizada. Os resultados mostram que as maiores doses de N (200 kg ha-1) aplicadas à cultura do
milho correspondem a maior teor de N mineral residual no solo após a coleta, o que se refletiu no
aumento da produtividade da aveia. À medida que houve incremento na produção de massa seca
aumentou também a quantidade de N recuperado pela aveia. Devido ao cultivo da aveia ocorreu
redução de até 87% do teor de N mineral residual no solo. Assim, pode atribuir-se à aveia uma
elevada capacidade em recuperar o N disponível no solo e aumentar a eficiência na sua utilização
reduzindo o risco de contaminação ambiental. Os adubos de liberação gradual demonstraram
também menores teores de N mineral no solo e riscos de perdas de N para o ambiente.
The experimental work was carried out at Quinta do Poulão in Bragança, NE Portugal in the years 2019 and 2020. The goals were to evaluate the oats capacity to use the residual nitrogen (N) from the corn crop grown in the previous season and the residual N in the soil in late summer (after maize harvest) and in Spring (after oat harvest). The experiment was conducted in a completely randomized design with 10 fertilizer treatments and three replications. Four rates of N applied as ammonium nitrate were used in two applications (pre-plant + sidedress). The N rates were 0 (0 + 0), 50 (25 + 25), 100 (50 + 50) and 200 (100 + 100) kg N ha-1. A controlled release fertilizer and a stabilized fertilizer with a nitrification inhibitor were also used, both in two rates applied at preplant (100 and 200 kg N ha-1). Farmyard manure was used in a dose equivalent to 100 kg N ha-1 applied at pre-plant and another similar treatment but supplemented with 100 kg N ha-1 applied as sidedressing as ammonium nitrate. The fertilizers mentioned were applied to the maize crop in May 2019. The oats were not fertilized. The results show that the highest rates of N (200 kg ha-1) applied to the maize crop corresponded to a higher residual mineral N content in the soil after harvest, which was reflected in the increase in of the productivity of oats. As there was an increase in dry matter production, the amount of N recovered by oats also increased. Due to the cultivation of oats, there was a reduction of up to 87% of the residual mineral N content in the soil. Thus, oats seem to have a high capacity to recover N available in the soil and increase its use efficiency, reducing the risk of environmental contamination. The gradual release N fertilizers also showed lower levels of mineral N in the soil and lower risks of losses of N to the environment.
The experimental work was carried out at Quinta do Poulão in Bragança, NE Portugal in the years 2019 and 2020. The goals were to evaluate the oats capacity to use the residual nitrogen (N) from the corn crop grown in the previous season and the residual N in the soil in late summer (after maize harvest) and in Spring (after oat harvest). The experiment was conducted in a completely randomized design with 10 fertilizer treatments and three replications. Four rates of N applied as ammonium nitrate were used in two applications (pre-plant + sidedress). The N rates were 0 (0 + 0), 50 (25 + 25), 100 (50 + 50) and 200 (100 + 100) kg N ha-1. A controlled release fertilizer and a stabilized fertilizer with a nitrification inhibitor were also used, both in two rates applied at preplant (100 and 200 kg N ha-1). Farmyard manure was used in a dose equivalent to 100 kg N ha-1 applied at pre-plant and another similar treatment but supplemented with 100 kg N ha-1 applied as sidedressing as ammonium nitrate. The fertilizers mentioned were applied to the maize crop in May 2019. The oats were not fertilized. The results show that the highest rates of N (200 kg ha-1) applied to the maize crop corresponded to a higher residual mineral N content in the soil after harvest, which was reflected in the increase in of the productivity of oats. As there was an increase in dry matter production, the amount of N recovered by oats also increased. Due to the cultivation of oats, there was a reduction of up to 87% of the residual mineral N content in the soil. Thus, oats seem to have a high capacity to recover N available in the soil and increase its use efficiency, reducing the risk of environmental contamination. The gradual release N fertilizers also showed lower levels of mineral N in the soil and lower risks of losses of N to the environment.
Description
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
Avena sativa Cultura de captura Nitrogênio Adubação nitrogenada Poluição por nitratos