Perennial nitrogen-fixing plant biological nitrogen fixation parameter B values determination method

Abstract

The invention discloses a method for determining a parameter B value showing the nitrogen fixation of a perennial nitrogen-fixing plant from atmosphere in the agricultural science field. The nitrogen-fixing plants of the invention particularly refer to leguminous plants such as purple medic, sainfoin, Astragalus adsurgens Pall and so on. The method is as follows: sand oil, in which nitrogen is removed through the treatment, is placed into a culture container; a seed of a plant to be tested is planted into the sand soil; measures for preventing the growth of microorganisms such as algae and so on, are taken on the surface of the sand oil; adequate nitrogen-free solution is added to provide nutrition which is needed for the growth of the plant and does not contain nitrogen; distilled water is sprayed everyday according to designed amount to supplement moisture; the plant is mowed to sample when the plant reaches a flowering period; and a sample undergoes a green-removing process, is dried to a constant weight and is pulverized to assess a natural abundance value of <15>N in the plant sample to obtain the B value.

Description

technical field [0001] The invention relates to a method in the field of agronomy for measuring the parameter B value of perennial nitrogen-fixing plants fixing nitrogen from the atmosphere. The nitrogen-fixing plants in the invention particularly refer to leguminous plants, such as alfalfa, red bean grass, sandawang and the like. Background technique [0002] There are many methods for measuring biological nitrogen fixation, such as: nitrogen accumulation method, acetylene reduction analysis method, 15 N integration method, total N difference method, isotope dilution method, etc. Each of these methods has advantages and disadvantages. Acetylene reduction method: The disadvantage is that the amount of biological nitrogen fixation cannot be obtained directly and accurately, and it is not suitable for the quantitative determination of long-term symbiotic nitrogen fixation in the field. It can only measure the dynamics of nitrogenase activity in a short period of time, and the...

AI Technical Summary

Problems solved by technology

But its disadvantage is that the difference between nitrogen-fixing plants and non-nitrogen-fixing reference plants 15 Differences in N abundance are small, typically below 10‰, such that measurement errors and non-atmospheric nitrogen sources δ 15 The true difference in N becomes important

However, the prior art lacks a method for measuring the biological nitrogen fixation parameter B value of perennial plants with nitrogen fixation characteristics.