Growth, Chemical Composition, and Yield of Safflower as Affected by Exchangeable Sodium1

Abstract

AbstractIn greenhouse experiments, safflower was grown on a Yolo fine sandy loam, fertilized with N, P, and K, and treated with a NHCO3 to give six levels of exchangeable Na, ranging from about 2 to 45% with very little salinity. Half of the soil in each of the trials had received “Krilium” soil conditioner (0.2% by weight), the other half had not. A single lot of soil was used to grow two crops in succession, both of which were harvested prior to flowering. A third crop was grown to maturity on a second lot of soil. The exchangeable sodium percentage (ESP) remained reasonably constant during cropping. Increasing ESP levels up to 20 and 30% resulted in greatly increased growth as measured by dry weight of the tops. ESP levels higher than these were detrimental to growth and yield. Increasing the ESP decreased the K, Ca, Mg, and P, and increased the Na content of the leaves. The maximum seed yield and oil percentage occurred at ESP values of about 20 and 30 respectively. The seed yield was greatly increased by “Krilium”, and at ESP 20, the total oil yield was twice as high as that of the check. The fatty acid composition of the oil appeared to be unaffected by ESP levels.