Abstract:Since the green revolution (in the 1960s), the output of agricultural production has risen sharply owing to the development of breeding and farming techniques, while the nutritional quality of crops has been declining. In similar genetic background, nutrient contents decreased in unit volume of crops under the elevated atmospheric CO2 concentration. Since the green revolution, the decrease of nutrition in agricultural products may due to the elevated CO2 Using the plant growth chambers to respectively simulate CO2 level in the early green revolution(310 μmol/mol) and the current (400 μmol/mol), in this study rice, wheat and soybean (the main C3 crops) were selected to study the effects of elevated CO2 on the C, N, Fe, Zn contents in grains since green revolution. The results showed that the elevated CO2 had little effect on C concentrations in the grains of the three crops, with the change range of ±1.5%. Both N, Fe and Zn concentrations in grains generally showed decreased trends, but the decline did not reach the significant level. Besides, breeding techniques did not relieve the negative effect of elevated CO2 on grain nutritive quality.