Synopsis Response of flax and sorghum to zinc fertilization increased as the liming rate was increased from 2 to 6 tons of CaCO3 per 2 million pounds of Hartsells soil. Phosphorus fertilization did not affect zinc response. Best growth was obtained when the Ca/Mg ratio of the liming material as 2/1.

Two experiments were conducted in the greenhouse to compare the effects of chloride, sulfate, and carbonate salts on the yield and chemical composition of corn and tomato plants. Rates of these anions went as high as 25.32‐pound‐equivalents per 2 million pounds of soil. In the first experiment the chloride series yielded less corn than the other series. A differential moisture regime also resulted in a significant difference in corn yield in favor of the more moist condition. A succeeding crop of tomatoes did not grow properly even though well fertilized with phosphorus. It is postulated that high acidity may be a contributing factor in causing an apparent phosphorus deficiency in tomato plants. In a second experiment with tomatoes the yield data showed highly significant anion source, phosphorus rate, lime rate, and anion × lime and anion × rate of anion effects. At the highest rate of chloride the yield was less than at the other rates. A highly significant yield increase was found for liming and phosphorus fertilization. Chemical composition of the plant material reflected the effect of rates of chloride on the percent chlorine in the plant and the rates of sulfate on the percent sulfur. A significant effect of increasing the rate of chloride or sulfate on the phosphorus content of the plants was found.

A greenhouse experiment was conducted to evaluate the effects of adding organic matter to the soil on the availability of rock phosphate from two sources. The treated soils were cropped successively to Sudangrass, ryegrass, and two crops of red clover. Treatments receiving additions of organic matter yielded higher in most cases than the corresponding treatment without added organic matter. Increased yields were attributed to the additional P in the organic matter rather than to the beneficial effect of the organic matter on the availability of rock phosphate. Treatments receiving Florida rock phosphate yielded more than corresponding treatments receiving Tennessee rock phosphate.