Abstract: :The adsorption of high concentration of bicarbonate (HCO3 -)originated from calcareous soils which are rich in CaCO3 and CaCO3 itself are considered the main factors to cause zinc deficiency in crops.A solution culture experiment was conducted to investigate that, under deficient and sufficient Zn supply, the effects of CaCO3 and HCO3 -(addition as NaHCO3)addition on the growth and Zn absorption of two wheat cultivars (Xiaoyan22 and Zhengmai9023)and a barley cultivar (Xiyin2).The results showed that under deficient Zn supply condition, addition of bicarbonate caused the obvious chlorosis symptoms of the three crops tested, and with Zn supply, the symptoms were slighter ;meanwhile, bicarbonate obviously inhibited growth of barley and wheat plants, and Zn sufficient supply could alleviate the inhibition.Zn supply significantly increased Zn uptake of plants, and also the increase range in the shoots was higher than that in the roots ;the three test crops were all sensitive to Zn deficiency ;Zn uptake affected by bicarbonate was mainly through inhibiting seedling growth and Zn translocation from roots to shoots, and with HCO3 - addition barley had higher zinc translocation rate than wheat, and more Zn was accumulated in roots comparing to no HCO3 - addition in the nutrient solution. With HCO3 - addition, the Zn translocation rates of Xiaoyan22 and Zhengmai9023 decreased by 24.0 % and 23.4 %, respectively ;while barely increased by 31.1 %.The bicarbonate also greatly increased the pH of solution, but the extent of pH increase was relatively small when growing plants in the nutrient solution.Compared with HCO3 -, high content of CaCO3 had little influence on plant growth and zinc uptake, but showed obvious influence on the pH increase of nutrient solution.

Key words: CaCO3, Bicarbonate, Wheat cultivar, Zn, pH

CLC Number: 

• S143.72

• Q945.12