Ecophysiological Effects of Nitrogen on Soybean [ Glycine max (L.) Merr.]

Abstract

Soybean [Glycine max (L.) Merr.] is a leguminous plant with high nutritional and medicinal value. The goal of this research was to determine the optimal concentration of nitrogen, using Hoagland nutrient solution, which will enhance the productivity of soybeans. The specific objective of the study was to assess the effect of variation of nitrogen concentration on soybean growth and leaf chlorophyll concentrations. Soybeans were grown under three soil nitrogen amendments: low, medium, and high concentration of Hoagland nutrient solution and a control group. Soybeans were grown under controlled environmental conditions in the Biotronette ® environmental cham-ber. Temperature of the environmental chamber was regulated at 27°C and the photoperiod was set to 10 L: 14D. Soybeans grown in the low treatment group had the highest growth rate (1.03 ± 0.03 cm/day) compared to the control, medium, and high treatment groups. During the first chlo-rophyll analyses, the control group had the highest total chlorophyll concentration (216.25 ± 4.09 µg/mL/g). During the second chlorophyll analyses, the low treatment group had the highest total chlorophyll concentration (102.81 ± 14.54 µg/mL/g). Although no finding was statistically signifi-cant between groups, the low nitrogen treatment conditions had a trend towards producing more favorable physiological outcomes on soybeans.