Interactions of nitrogen, chlorine, and sulfate in the growth of burley tobacco
A field experiment was conducted to study the effect of rates of nitrogen and muriate and sulfate of potash upon the growth, chemical composition, and quality of the Burley 21 variety of tobacco. Rates of nitrogen applied were 75, 150, 225, and 300 pounds per acre. The muriate and sulfate sources of potash were combined on a equivalent basis in the following proportions: 100 SO₄/0 Cl, 75 SO₄ /25 Cl, 50 SO₄ /50 Cl, 25 SO₄/75 Cl, and 0 SO₄ /100 Cl.
The application of nitrogen increased the nitrogen content in the plant during the growing season and of cured leaves, except for the 150 pound rate which decreased the content. Applied nitrogen rates had no effect upon growth or yield above soil derived nitrogen. Chlorine content of growing plants and cured leaves was increased by the addition of 150 pounds of nitrogen. Above 150 pounds, the chlorine content sharply decreased, indicating that anion competition occurred between nitrogen and chlorine ions.
The sulfate-chlorine treatments increased the sulfate content as the proportion of sulfate increased and increased chlorine content as the proportion of chlorine increased. The treatments did not significantly alter yield or acre value of cured leaves.