Effects of Chromium in Lou Soil on Growth and Development of Corn and Wheat
Xiao Ling Xue Chengze(.Research Lab for Protection of Agricultural Environment)
Pot experiments with Lou soil have shown that the effects of Cr upon the growth and development of corn and wheat are related, to its valences and concentration. The higher the concentration, the greater the toxicity to crops; and the toxicity of Cr (Ⅵ) is higher than that of Cr (Ⅲ) . When the concentration of Cr (Ⅲ) is higher than 5 ppm, some damage occured to plant leaves and stems, and the dry matter is reduced by 10%. When the concentration is over 10 ppm, plants start to die. However, damages caused by Cr (Ⅲ) appear only when the concentration is over 400 ppm. The damage symptom appearing for wheat is 40 ppm from Cr (Ⅵ) and 200 ppm from Cr (Ⅲ) . The content of Cr in wheat grain is higher than that in corn grain, and for the same crop, Cr contents in leaves and stems are greater than those in grains. In addition, CrCl3 has stronger toxicity to crops than Cr2(SO4)3.