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Silicon (Si) application may affect the plant response to nitrogen (N), possibly by changing the uptake, concentration, and partitioning of nutrients in plant tissues; however, this has not yet been proven in Arabica coffee plants. The effects of Si application methods [no Si, soil-applied soluble Si (168 mg Si L−1), and foliar-applied soluble Si (two application of 2 mg Si plant−1)] and N levels (0 and 80 mg N L−1) on biomass production and partitioning and uptake, partitioning, and stoichiometry of nutrients and Si in young Arabica coffee plants grown under greenhouse conditions were evaluated. Nitrogen fertilization increased the biomass production and uptake of all nutrients; however, reduced the concentrations of K, Ca, Mg, S, Mn, and Si in the leaves, Si in the stems, and K, Mg, and S in the roots of coffee plants as a dilution effect. In the presence of N, soil-applied Si increased the concentrations of Zn in the leaves and Ca and Si in the stems, the uptake of K, S, and Si, and the Si:N ratio. Foliar-applied Si increased the concentrations of N, P, K, and Zn in the leaves and Ca and Si in the stems, as well as the total uptake of K and Si and the Si:N ratio in coffee plants, being more evident in the N fertilization presence. This study unraveled that, especially when it was soil-applied, Si altered the nutrient uptake, allocation, and stoichiometric ratios with N, with a consequent increase in biomass production of young coffee plants fertilized with N. [ABSTRACT FROM AUTHOR]

Nitrogen (N) plays a fundamental role in the initial growth of the Arabica coffee plant whereas silicon (Si) is key in enhancing performance of the plant through promoting N-use efficiency (NUE). This study evaluated the effect of N rates (0, 40, 80, and 160 mg dm−3) and Si application methods (no Si, soil-applied soluble Si, and foliar-applied soluble Si) on growth, dry matter (DM) accumulation, N and Si uptake, and NUE of young Arabica coffee plants under greenhouse conditions. Nitrogen fertilization increased the height, number of plagiotropic branches, nodes in plagiotropic branches and leaves, leaf area, root length, DM production, and N and Si uptake of the coffee plant. Results revealed that both soil and foliar application of Si increased plant height. In the presence of the highest N rates, the soil application of Si increased the number of nodes in the plagiotropic branches, length and DM of roots, and Si uptake by coffee plants. In addition, soil application of Si increased NUE indexes, an indication that it can improve performance of the young coffee plants in the field. [ABSTRACT FROM AUTHOR]