Contributions of atmospheric sulfur (S) to soil fertility at 15 locations in South Carolina were estimated during the 5‐year period 1973–77 by measuring the S content of precipitation samples accumulated at 30‐day intervals and by measuring the S collected in lead peroxide samplers exposed to the air at the same time intervals. The S content of precipitation was compared with similar data collected at three locations in 1953–55. Concurrently with the 1973–77 study, long‐term uniform field experiments designed to measure response of seven crops to S added in the fertilizer were conducted at selected locations. The mean estimated annual amount of S added to the soil in precipitation for the period 1973–75 was 11.3 kg per ha. The corresponding addition in 1953–55 was 6.3 kg/ha. The mean estimated amount of S added to the soil from the air and precipitation increased from 11.2 kg/ha in 1973 to 19.8 kg/ha in 1977. Sulfur added in the fertilizer resulted in an increased yield (10% probability level) for one crop at one location.
Two experiments were conducted to study the effects of spacing on the cured leaf of flue‐cured tobacco. One involved different numbers of skipped rows and the other involved plant spacings within the row. Yields increased as the number of skipped rows increased. Also, the value per 45.35 kg increased as the number of skipped rows increased, which may indicate a better quality of tobacco produced with the wide rows. Alkaloid content was somewhat lower as the number of skipped rows increased, and the filling value decreased as the number of rows increased. In comparing the common practice of planting four rows and skipping one to the older method of continuous rows, there seemed to be little difference in the cured leaf for reducing sugars, total alkaloids, filling value, or equilibrium moisture content. However, an increase in yield (92 kg) and value per hectare ($188.00) was obtained by skipping every fifth row. In general, the more plants per acre the greater the yield when the plants were topped to a common leaf number. Wider spacings within the row gave the higher value per 45.35 kg; however, there was no difference between the 61‐ and 69‐cm spacing. There was little difference in reducing sugars for any of the spacings, but there was a tendency for alkaloids to increase as spacings increased. Distance between plants in the row seemed to have little effect on filling value and equilibrium moisture content. Results indicate that above 61‐cm spacing in the row is too wide and that close spacing although producing more money return per hectare may tend to reduce the quality of the cured leaf.
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