NITROGEN DOSES, USE AND EFFICIENCY IN SIX CORN CULTIVARS

• Main Authors: FLÁVIA CARVALHO SILVA FERNANDES, SALATIÉR BUZETTI, ORIVALDO ARF, JOÃO ANTONIO DA COSTA ANDRADE
• Format: Article
• Language: English
• Published: Associação Brasileira de Milho e Sorgo 2005-08-01
• Series: Revista Brasileira de Milho e Sorgo
• Subjects: N rates: cultivars; N-plant: nitrogen fertilization
• Online Access: http://rbms.cnpms.embrapa.br/index.php/ojs/article/view/140/138

Corn needs high amount of nitrogen and this element in soil shows fluctuation due to humidity degree. In addition, cultivars show different performance to N supply. This work aimed to study nitrogen doses, use and efficiency in six corn cultivars, cropped in a cerrado soil vegetation area, Selviria-MS, in a clayey, hipodistrophyc, alic, red latosol (Haplustox). The plots were constituted of six 5-meter-long lines spaced 0.80 m, with 5 plants per meter.It was used a completely randomized block design in a factorial scheme with 4 nitrogen rates and 6 cultivars in 6 replications . N was applied at rates of 0, 30, 90 and 180 kg ha-1, to 30 kg ha-1 at sowing (control did not receive N) and the rest in side-dressing at 6-8 leaf stage. It was evaluated the number of lines per ear and grains per ear line, diameter of colm, size of ear, number of ear per 10 m, mass of 100 grains, dry mass of plant at flowering and physiological maturation, grain yield and use and efficiency of N, obtained by relation between grain yield and N applied to soil, besides the components of N efficiency. The cultivars showed statistical difference among them and the highest estimated yield was reached with 110 kg ha-1 of nitrogen. The N use efficiency decreased every time there was a dose increase .The DKB 333B hybrid showed the highest efficiency and the BR 106 and the Sol da Manhã hybrids the lowest one.