利用同位素~(15)N对豆科作物固氮量测定的研究

本文报导了利用同位素~(15)N对豆科作物固氮量测定的研究。结果表明,~(15)N-A值法和总氮差值法测定五个大豆品种和两种豆科牧草的固氮量值显著相关,两方法的测定结果明显地呈线性关系。通过比较非固氮作物重复间总氮测量值和~(15)N％原子超测定值变异系数的大小,表明用A_N值法估计固氮百分率比用总氮差值法可靠,试验结果还表明,A_N值法测定固氮量比总氮差值法和乙炔还原法具有一定的优越性。

Determination of nitrogen fixation of legume crops using isotope ~(15)N

Method for determination of N2 fixed by legume crops is reported. By difference method and 15N-A value method the amount of total N2 fixed and percentages of total N2 fixed by 5 soybeans and 2 species of legume grasses are highly corrected (r = 0.96, y = 1.051x 0.037 for the amount of N2 fixation and r = 0.39, y = 0.245x 43.597 for the percentage of N2 fixation). It is shown that the estimated percentage of N2 fixed by AN- value method is more reliable than by difference method as a result of comparing the variation coefficents of total amount of N with the variation coefficents of 15N% atom excess for non-fixing N2 crops. It is found that the AN-value method has more advantageous than the difference method and the acetylene-ethylene method for measurement of dini-trogen fixation.