Nitrate nitrogen leaching method in a kind of soil

Abstract

The invention provides a method for leaching nitrate nitrogen in soil, which is suitable for leaching nitrate nitrogen in soil samples, and distilled water is used instead of potassium chloride solution to obtain the content of nitrate nitrogen in soil. On the basis of ensuring the accuracy of the data, the experimental cost is saved; the damage to the instrument by the potassium chloride solution is effectively avoided. The salt effect is effectively avoided, and the extraction effect is better. It is proved by experiments that the extraction efficiency is increased by 11.1% to 34.2%. The adverse effect of potassium chloride on the environment is avoided, which is conducive to reducing and eliminating pollution from the source, and conforms to green chemistry.

Description

technical field [0001] The invention relates to a method for leaching nitrate nitrogen in soil. Background technique [0002] Nitrate nitrogen is a soil nutrient, which reflects the change degree of nutrients in the soil at different times. Now, the nitrate nitrogen in the soil is leached with potassium chloride solution, and the nitrate nitrogen is measured with a continuous flow analyzer. The principle of the method is that the nitrate in the extraction solution is reduced to nitrite through the red copper-plated cadmium column with the ammonium chloride solution as the substrate, and it forms a red azo chromophore with the diazonium compound agent and the coupling reagent, and the red intensity is the same as The nitrate nitrogen content is directly proportional. First of all, due to the salt effect (salt effect), the potassium chloride leaching solution cannot completely extract the nitrate nitrogen in the soil ("Study on the Combined Water-salt Stress Effect and Water...

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Problems solved by technology

First of all, due to the salt effect (salt effect), the potassium chloride leaching solution cannot completely extract the nitrate nitrogen in the soil ("Research on the joint water-salt stress effect and water efficient use of crops", Shi Haibin et al., Beijing, China Water Conservancy and Hydropower Press 2009.1)

In addition, since the potassium chloride extract is a high-concentration salt solution, if the sample is not washed with a large amount of water in time after the sample is tested, the potassium chloride in the extract is easy to precipitate and block the pipeline. Potassium chloride crystals precipitated at the road interface

Moreover, if the pipeline leaks or is accidentally spilled when adding samples, the salt solution will corrode the instrument.

Potassium chloride has an adverse impact on the environment; the use of potassium results in increased costs

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