Effects of Nutrient Supply on Pre-emergence Growth and Nutrient Absorption in Wheat (Triticum aestivumL.) and Sugarbeet (Beta vulgarisL.)

Nutrient absorption in wheat and sugarbeet was studied during pre-emergence growth by adding 0, 7, 10.5 or 14 mol m −3 nitrogen (N) to the growth medium. Seedling growth and carbon, N and 15 N contents of the seedling parts were measured. Differences between the natural abundance of 15 N in seeds and in nutrient solution were used to determine the proportion of N in the organs originating from seed reserves and from absorption. Absorption began later for wheat than for sugarbeet and had less effect on seedling growth. The absorbed N was found mainly in roots. Compared to wheat, sugarbeet seedling N content was greatly altered and the hypocotyl showed increased elongation when nutrients were added. Most of the absorbed N was found in the radicle and hypocotyl with less in the cotyledons. Sugarbeet seedling emergence and early growth could be decreased by adverse conditions occurring after sowing by affecting mineral availability in the soil or through altered root absorption.