Nitrogen Fertilization on Maize Sowing:Plant Growth and Seed Vigor

摘要

The management of fertilization in maize plants is a preponderant factor in the search for higher yields and obtaining quality seeds. In this sense, the study of nitrogen (N) management is predominant in improving the efficiency of its application. The objective of this study was to evaluate the growth, partition assimilation and vigor expression of maize seeds submitted at different doses of nitrogen applied at sowing. The treatments were constituted by different doses of nitrogen fertilization at sowing, being: 25%, 50%, 75% and 100% of the recommended dose for the crop, according to the recommendation of nitrogen fertilization. The plants were collected at regular intervals of 21 days after sowing until the end of the growth cycle. For the analysis of growth and partition of dry matter between the organs, the accumulation of dry matter and leaf area was measured. The experimental design was randomized blocks in a 4 × 7 factorial scheme (four N rates at sowing and seven collection times with three replications). The maize plants under the influence of nitrogen fertilization at sowing presented differential growth and distinct responses in the assimilated partition between their structures, with the intensity dependent on the dose used. Plants grown using 75% of the recommended dose of N at sowing had a higher relative growth rate, with more pronounced effects compared to the other doses. The expression of maize seed vigor increases to an increase of 82.5% N at sowing.