Effects of nitrogen levels on growth, yield and nitrogen uptake of fiber-rich cultivar, Goami 2

Abstract

To investigate the effect of nitrogen (N) application level on fiber-rich cultivar, Goami 2, an experiment was carried out on a paddy soil at the rice experimental farm of the National Institute of Crop Science (NICS), Rural Development Administration (RDA) in Suwon, Korea. Rice growth, yield and its components for Goami 2 were investigated under different N application levels (0, 50, 70, 90, 110, 130 and 150 kg ha^-1). Goami 2 showed higher SPAD values and N content in plant than that of Daean (reference cultivar) at 29 days after transplanting (DAT), but lower at 93 DAT. The ammonium-N (NH_4-N) increased in the Daean cultivated soil, but decreased in the Goami 2 cultivated soil at 93 DAT. Among yield components, brown to rough rice ratio, liter (ℓ) weight, and 1,000-grain weight of Goami 2 were lower compared to Daean as reference cultivar. Also, hulled rice yield decreased. The N application levels of Goami 2 from 70 to 150 kg ha^-1 did not show significant different in view of yield and N efficiency. We also found out that a number of small vascular bundles (SVB) in the stem of Goami 2 were significantly lower in the stem of Goami 2 than those of Daean. Therefore, the optimum N application level of Goami 2 was at the 70 kg ha^-1, considering the yield of milled rice and N efficiency.

Key words: Rice, nitrogen, N efficiency, yield, SEM.