Determination of dry weight, nitrogen content, and sulfur content of radish (Raphanus sativus) plants exposed to simulated acid rain
Effects of acid rain on the dry weight, nitrogen and sulfur content of radish plants were determined. They were exposed to distilled water acidified with a 7:3 ratio of sulfuric acid and nitric acid and adjusted to pH levels 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, and 5.7. A control group, exposed to distilled water only, was also used. Four hundred plants, divided in eight groups, were grown under laboratory conditions. At four, seven and ten week intervals, an equal number of plants of each pH level were removed from the soil.Plants exposed to water of lower pH values were found to be significantly higher (p < .05) in dry weight, percentage of nitrogen, and weight of sulfur per plant than crops at more neutral pH levels. The increased weight may be due to the greater availability of nitrates and sulfates at lower pH levels. These compounds probably contributed to better growth and greater dry weight of the plants at low pH levels.