Abstract
Effects of fractional application of nitrogenous fertilizer (ammonium sulfate 150 lbs. per acre) on potato growth and yield were tested in 1953. Ammonium and nitrate nitrogen contents in the soil, and nitrogen contend in the plant were periodically analyzed. The variety used was Irish Cobbler. Experimantal plots were ramdomized and every treatment was replicated four times.
The highest yield of potato tuber was obtained in the treatment where total amount of the fertilizer was applied at the time of planting, and the lowest was in the treatment where every tenth were applied in ten times at a week intervals. Yields in the treatments where the fertilizer was fractionally applied in two or five times were intermediate between the above two treatments.
Ammonium and nitrate nitrogen contents in the soil were maintained at relatively higher level in the treatment where the total amount of the fertilizer was applied at one time until the later part of the growing season. In the treatment where the fertilizer was fractionally applied, nitrogen level in the soil were not high enough to maintain the vigorous growth of the plants, especially in the early part of the growing season.
