Macronutrients in the soil are essential to the growth and development of a plant. One of the most important nutrients to a plants growth is nitrogen. Nitrogen has been directly correlated to photosynthetic output in various studies and this relationship is the subject of this experiment. Since nitrogen has an effect on photosynthetic rate, there should be a correlation between nitrogen and fluorescence – a form of energy dissipation. This study attempted to show that nitrogen concentration in the soil is inversely proportional to fluorescence of the plant because the more nitrogen in the soil, the more energy should be used for photosynthesis rather than energy dissipation. Zea mays was chosen as the species of study because of its rapid growth rate and economical value to society. Hoagland’s solution was used as a baseline for the amount of nitrogen utilized by a plant in a naturally occurring setting. Distinct groups were made using the baseline solution as the normal concentration of nitrogen. Then, two other groups were set up – one with half the concentration and another with double the concentration. Using a pulse-modulated Fluorometer, fluorescence was obtained from the plants in each of the groups under normal light, as well as under light stress. In addition, both dark-adapted and light-adapted fluorescence were measured. The results revealed that, under both normal light and light stress, light-adapted fluorescence was significantly different between our three groups. This would suggest that under highly stressful conditions, nitrogen is helpful in utilizing more energy for photosynthesis and energy dissipation is minimized.
Garbutt, Ashton; Rossie, Daniel; and Solsi, Anup, "The Effect of Nitrogen Soil Concentration on Leaf Fluorescence in Zea Mays" (2011). Pepperdine University, All Undergraduate Student Research. Paper 31.