Summary In Brazil, high-yield soybean [ Glycine Max (L). Merrill] – corn ( Zea mays L.) double cropping system might be nitrogen (N)-limited and additional N fertilization can beneficial. Early application of in reduces the symbiotic fixation (SNF) efficiency and/or establishment. One alternative to avoid SNF impairment is apply between beginning pod (R3) seed-fill (R5) stages through use contr...