ABSTRACT Soybean and corn succession system widely adopt in different agricultural regions from Brazil. However, different species incorporation, especially in the autumn/winter season, can influence the soybeans profitability in succession system and farm economic return, providing benefits for the agricultural sector. The objective this work was to analyze the development of different species in the autumn-winter crop and the influence on soybean yield and the economic return of farm in Midwest of Paraná, Brazil. The study was conducted during 2019/2020 and 2020/2021 crop. A completely randomized design adopted, with eight treatments (autumn/winter season) and four replications. In autumn/winter season were composed of five crops in single system (black oat, brachiaria ruziziensis, oilseed radish, corn and wheat), two in intercropped systems (black oat with oilseed radish and corn with brachiaria) and fallow area (spontaneous plants). In the spring/summer season, soybean was cultivated. The biomass produced in the autumn/winter season varies with the species and cultivation system adopted. Soybean yield is higher when cultivated in succession to brachiaria, while the worst performance is obtained in succession to spontaneous plants. The cultivation of wheat in the winter and soybeans in the summer presents superior economic performance.

ABSTRACT The application of silicon (Si) in plants benefits the performance of several species. However, the dynamics of the element, mainly in non-accumulating species such as tomatoes, are rarely analyzed. This study investigated the dynamics of Si in tomato plants cultivated under different forms of application and water conditions. The experiment was carried out in a completely randomized design with four replications, using a factorial scheme 2 x 4: two water conditions (60 and 100% of the evapotranspiration of the crop - ETc), and four forms of silicon application (without application, full dose applied at soil, split dose applied at soil, and foliar application). Si content in the soil and in the different plant organs were analyzed. Si content in the soil increased after the crop cycle depending on the application form (full or split doses). The dynamics of Si accumulation and extraction by tomato are influenced by the application form (higher in soil application) and water management, with fruits and leaves having the higher values. Si application, mainly in the soil, increased the rate of Si accumulation and extraction by tomatoes cultivated in different water conditions.

RESUMO A aplicação de silício em plantas ocasiona benefícios no desempenho de diversas espécies. Entretanto, a dinâmica do elemento, principalmente em plantas de espécies não acumuladoras como o tomate, é pouco analisada. O estudo teve como objetivo analisar a dinâmica do silício no cultivo do tomate em diferentes condições hídricas e formas de aplicação do elemento. O experimento foi conduzido em delineamento inteiramente casualizado com quatro repetições, adotando esquema fatorial 2 x 4: duas condições de reposição hídrica (60 e 100% da evapotranspiração da cultura - ETc), quatro formas de aplicação de silício (sem aplicação, aplicação no solo de dose total, aplicação no solo de dose parcelada e aplicação foliar). Foi analisado o teor de silício no solo e nos componentes vegetais do tomateiro. O teor de silício no solo após o cultivo foi elevado em função da aplicação do elemento, em dose total ou parcelada. A dinâmica de acúmulo e extração do silício pelo tomateiro é influenciada pelo manejo hídrico e pela forma de aplicação do elemento, sendo as maiores taxas no fruto e na folha. A aplicação do elemento, principalmente no solo, elevou a taxa de acúmulo e extração do silício pelo tomateiro cultivado em diferentes condições de reposição hídrica.