Two field experiments were carried out in Agric. Expt. Farm, Fac. of Agric., Ain Shams Univ. at Shalakan, Kalubia Governorate, Egypt during 2014 and 2015 growing seasons. These experiments aimed to study the effect of integrated between mineral nitrogen fertilizer (60, 90 and 120 kg / fad) and Humic acid (0, 15 and 20 kg / fad) on productivity and nitrogen partitioning dynamic of maize (zea maize) plants:
Plants treated with120 kg MN/fad + 20 kg HA and 120 kg MN/fad + 15 kg HA gave the highest values of ear weight (264.9 and 257.4 g), shelling percentage(85.37 and 84.67 % ),plant height (284.2 and 279.7 cm), 100 kernel weight (40.20 and 39.09 g),stover yield (9.33 and 9.13 ton/fad) and biological yield (13.10 and 12.66 ton/fad) respectively. Maximum grain yield (3.76 ton/fad) was obtained when plants were fertilized with 120 kg MN. + 20 kg HA. Meanwhile, the lowest value (1.98 ton/fad) was recorded when plants were fertilized with 60 kg MN.
Results also showed that grain nitrogen (%), stover nitrogen %, biological nitrogen %, grain nitrogen yield (kg/fad), stover nitrogen yield (kg/fad), total nitrogen yield (kg/fad), GCP % and GCPY (kg/fad) were significantly the highest due to fertilization with 120 kg MN/fad + 20 kg HA/fad. Such potent treatment increased the previous traits by 1.723%, 0.413%, 2.14%, 64.94 (kg/fad), 38.58 (kg/fad), 103 (kg/fad), 9.82 % and 370.2 (kg/fad), respectively.
Data also cleared that the effect of integration between mineral nitrogen fertilizer and humic acid were significantly differed in NUE, NRE%, NPF and NHI%.