Controlled release urea increases soybean yield without compromising symbiotic nitrogen fixation

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 controlled release fertilizers. this study, was applied at 50 kg ha −1 as common urea (CU) or (CRU) with different lag periods until starts (30 days, 60 1:1 mix both times) a randomized complete blocks design six treatments four replicates under tropical subtropical conditions. CU after emergence (VE) (R3), CRU only VE. Using labeled 15 isotope, we analyzed source used by (fertilizer, soil, SNF) parameters. On average, 30 + days) R3 stage increased grain yield 9.2% (354 ) compared control. derived from all fertilizer treatment were almost 35 , high recovery 68%. The not impaired accounted for 71% (220 total uptake. conditions experiments, shown effective supply late demand (R3 stage), increasing without damaging process environments.