六种作物不同生育期吸收按、硝态氮的特性

采用溶液培养研究了6种作物不同生育期吸收铵、硝态氮的特点及其吸收动力学。结果表明，在铵、销态氮等量共存条件下，6种作物对按、硝态氮的吸收比例因生育时期不同而有一定的阶段性和偏向性。这种偏向性可以用吸收动力学参数(Vmax，Km)予以解释。根据试验结果，对溶液培养方法的可靠性和准确性进行了评价。

Characteristics of Absorbing Ammonium and Nitrate Nitrogen of Six Crops at Different Growth Stages

Solution culture experiments were conducted and the uptake kinetics and absorbing characteristics of ammonium and nitrate nitrogen were studied in six crops during different growth stages by using a solution in which both ammonium-N and nitrate-N were present equally in amounts. The results showed that the absorbed ratios of ammonium-N to nitrate-N, or the preference to either ammonium-N or nitrate-N, by these crops varied with their growth stages. The preference of one form to the other is dependent on both crops and their growth stages. This preference might be explained by the use of the kinetic parameters(Vmax, Km)of absorption. In addition, the reliability and accuracy of the solution culture method were evaluated.