Chia Response to Nitrogen Fertilization at Two Sowing Dates under Subtropical Conditions

Abstract

ABSTRACT The study aimed to determine the response of chia (Salvia hispanica) to nitrogen (N) fertilization at different sowing dates in southern Brazil. The experiment was arranged in a randomized block design with four replicates (5x2 factorial arrangements). Five N doses (0, 30, 60, 90, and 120 kg N ha−1) were used at two sowing dates (November, preferred, January, late). Growth variables, organ N concentrations, and grain yield were evaluated. Fertilizer N recovery efficiency, maximum technical, and economic efficiency were calculated. N doses applied via fertilizer at sowing in November provided the greatest effect on growth parameters and grain yield of chia, and a dose of 104 kg N ha−1 had the highest technical and economic efficiency. The higher NRE was in November at the dose of 30 and 60 kg N ha−1, and it was decreasing with the increased N dose. The meteorological conditions of the preferred sowing combined with the high doses of N promoted increased N supply in the soil, which was effectively absorbed and converted to shoot dry weight. November is the best time to sown chia and 104 kg N ha−1 is the most suitable dose.