TY - EJOU AU - RE, Brevedan AU - Fioretti, MN AU - Baioni, SS AU - Palomo, IR AU - Laborde, H TI - Nitrogen fertilization of irrigated soybean T2 - Phyton-International Journal of Experimental Botany PY - 2007 VL - 76 IS - all SN - 1851-5657 AB - A long-term study was conducted at different locations of Southwestern Buenos Aires to evaluate the effects of N fertilization at different growth stages of soybean on yield, plant nitrogen concentration and seed protein and oil concentrations. Yields were increased in six out of ten trials, and the response was highest with N fertilization at the beginning of grain development (R5). Different nitrogen sources were applied at seeding which gave higher yields and increased seed protein content than the non-fertilized, non-nodulated treatment. Urea was the most effective N source. KW - soybean KW - nitrogen fixation KW - combined nitrogen KW - irrigation DO - 10.32604/phyton.2007.76.153