CN-121994731-A - Rapid test method and application of hydrolytic nitrogen in soil

CN121994731ACN 121994731 ACN121994731 ACN 121994731ACN-121994731-A

Abstract

The application discloses a rapid test method and application of hydrolytic nitrogen in soil, and relates to the field of soil detection, wherein the method comprises the steps of mixing a dry soil sample with ultrapure water for shake extraction; the method comprises the steps of testing a first test sample through a Navier reagent spectrophotometry to obtain water-soluble ammonia nitrogen content, testing a second test sample through an ion chromatography to obtain water-soluble nitrate nitrogen content and water-soluble nitrite nitrogen content, and obtaining ammonia nitrogen hydrolytic nitrogen content, nitrate hydrolytic nitrogen content and nitrite hydrolytic nitrogen content based on a constant volume, the mass of a dry soil sample, water-soluble ammonia nitrogen content, blank water-soluble ammonia nitrogen content, water-soluble nitrate nitrogen content, blank water-soluble nitrate nitrogen content, water-soluble nitrite nitrogen content and blank water-soluble nitrite nitrogen content, thereby adopting pure water oscillation leaching, and adding after classifying the hydrolytic nitrogen existence form to realize rapid and accurate test of hydrolytic nitrogen in soil.

Inventors

ZHANG GENGYU
LI WEIZHI
WANG SHUANGLONG
ZHANG RU
WANG CONG
WANG SHIWEI
CUI HAIYANG
LIU HONGPENG
ZHANG XIAXIA
ZHU GE

Assignees

吉林省吉林生态环境监测中心

Dates

Publication Date: 20260508
Application Date: 20260129

Claims (10)

1. A method for rapidly testing hydrolytic nitrogen in soil, comprising: obtaining a soil sample, and processing the soil sample to obtain a dry soil sample; mixing the dried soil sample with ultrapure water, performing vibration extraction to obtain a soil mixed solution, and performing suction filtration and filtration treatment on the soil mixed solution to obtain a soil leaching solution; Dividing the soil leaching solution into a first test sample and a second test sample, carrying out water-soluble ammonia nitrogen test on the first test sample by a Navier reagent spectrophotometry to obtain water-soluble ammonia nitrogen content, and carrying out water-soluble nitrate nitrogen and water-soluble nitrite nitrogen test on the second test sample by an ion chromatography to obtain water-soluble nitrate nitrogen content and water-soluble nitrite nitrogen content; Obtaining a blank water-soluble ammonia nitrogen content value, a blank water-soluble nitrate nitrogen content value and a blank water-soluble nitrite nitrogen content value for blank control; Obtaining ammonia nitrogen hydrolytic nitrogen content, nitrate hydrolytic nitrogen content and nitrite hydrolytic nitrogen content based on the constant volume of the soil sample, the mass of the dry soil sample, the water-soluble ammonia nitrogen content, the blank water-soluble ammonia nitrogen content value, the water-soluble nitrate nitrogen content, the blank water-soluble nitrate nitrogen content value, the water-soluble nitrite nitrogen content and the blank water-soluble nitrite nitrogen content value; Calculating the sum of the ammonia nitrogen hydrolytic nitrogen content, the nitrate hydrolytic nitrogen content and the nitrite hydrolytic nitrogen content to obtain the soil hydrolytic nitrogen content.
2. The method for rapidly testing hydrolyzable nitrogen in soil according to claim 1, wherein the steps of obtaining an ammonia nitrogen hydrolyzable nitrogen content, a nitrate hydrolyzable nitrogen content and a nitrite hydrolyzable nitrogen content based on a volume of a soil sample, a mass of a dry soil sample, the water-soluble ammonia nitrogen content, the blank water-soluble ammonia nitrogen content value, the water-soluble nitrate nitrogen content, the blank water-soluble nitrate nitrogen content value, the water-soluble nitrite nitrogen content and the blank water-soluble nitrite nitrogen content value specifically include: Calculating a difference value of the water-soluble ammonia nitrogen content and the blank water-soluble ammonia nitrogen content as a first difference value, multiplying the first difference value by the constant volume of the soil sample to obtain a first product, and calculating the ratio of the first product to the mass of the dry soil sample to obtain the ammonia nitrogen state hydrolytic nitrogen content; Calculating a difference value of the water-soluble nitrate nitrogen content and the blank water-soluble nitrate nitrogen content as a second difference value, multiplying the second difference value by the constant volume of the soil sample to obtain a second product, and calculating the ratio of the second product to the mass of the dry soil sample to obtain nitrate hydrolytic nitrogen content; And calculating a difference value between the water-soluble nitrite nitrogen content and the blank water-soluble nitrite nitrogen content as a third difference value, multiplying the third difference value by the constant volume of the soil sample to obtain a third product, and calculating the ratio of the third product to the mass of the dry soil sample to obtain the nitrite hydrolytic nitrogen content.
3. The method for rapidly testing hydrolytic nitrogen in soil according to claim 1, wherein the step of treating the soil sample to obtain a dry soil sample comprises: And (3) drying the soil sample, grinding and crushing, and filtering by a 100-mesh sieve to obtain a dried soil sample with the particle size not more than 0.15 mm.
4. The method for rapidly testing the hydrolytic nitrogen in the soil according to claim 1, wherein the steps of mixing the dry soil sample with ultrapure water, performing shake extraction to obtain a soil mixed solution, and performing suction filtration and filtration treatment on the soil mixed solution to obtain a soil leaching solution comprise the following steps: Placing 2.0g of the prepared dry soil sample into a 100mL colorimetric tube with a plug with scales, adding 70-100 mL of experimental ultrapure water, and extracting by horizontal shaking to obtain a soil mixed solution; And (3) transferring the soil mixed liquid into a suction filtration device for suction filtration, and filtering the soil mixed liquid subjected to suction filtration through a filter membrane to transfer the soil mixed liquid subjected to the filtration treatment into a 100mL volumetric flask for constant volume to obtain a soil leaching solution.
5. The rapid test method for hydrolytic nitrogen in soil according to claim 4, wherein the condition of vibration extraction is that the vibration frequency is 300-500 rpm, and the extraction time is 30-45 min.
6. The method for rapid testing of hydrolyzable nitrogen in soil according to claim 4, wherein said filter is a 0.45 micron pore filter.
7. The method for rapidly testing hydrolyzable nitrogen in soil according to claim 1, wherein said step of obtaining a blank water-soluble ammonia nitrogen content value, a blank water-soluble nitrate nitrogen content value and a blank water-soluble nitrite nitrogen content value for a blank control specifically comprises: And taking 2g of quartz sand as a soil blank control sample, and performing oscillation extraction, suction filtration, filtration treatment, water-soluble ammonia nitrogen test, water-soluble nitrate nitrogen and water-soluble nitrite nitrogen test which are the same as those of the dry soil sample on the quartz sand to obtain a blank water-soluble ammonia nitrogen content value, a blank water-soluble nitrate nitrogen content value and a blank water-soluble nitrite nitrogen content value.
8. The method for rapidly testing hydrolyzable nitrogen in soil according to claim 1, wherein said step after obtaining the content of hydrolyzable nitrogen in soil further comprises: And correspondingly adjusting the quality of the dry soil sample or the constant volume according to the detection result of the content of the hydrolyzed nitrogen in the soil, so that the measurement concentration of the content of the water-soluble ammonia nitrogen is within the curve test range of the Nahner reagent spectrophotometry, and the content of the water-soluble nitrate nitrogen and the content of the water-soluble nitrite nitrogen are within the curve test range of the ion chromatography.
9. The method for rapid testing of hydrolyzable nitrogen in soil according to claim 1, further comprising: And collecting a plurality of standard soils with different soil hydrolytic nitrogen contents as quality control samples, and synchronously carrying out all the processes of soil hydrolytic nitrogen testing with the soil samples to be tested so as to obtain corresponding quality control testing results respectively.
10. Use of the rapid test method of hydrolytic nitrogen in soil according to any one of claims 1 to 9 in soil nitrogen supply capability evaluation technology.

Description

Rapid test method and application of hydrolytic nitrogen in soil Technical Field The application relates to the field of soil detection, in particular to a rapid test method for hydrolytic nitrogen in soil and application thereof. Background The hydrolytic nitrogen of the soil can represent the nitrogen which can be actually absorbed and utilized by crops in the soil, namely effective nitrogen or quick-acting nitrogen, the content of the hydrolytic nitrogen can judge the nitrogen supply capacity of the soil, and the hydrolytic nitrogen further guides reasonable fertilization, thereby having important significance. The hydrolytic nitrogen in the soil exists in the form of inorganic nitrogen composed of ammonium nitrogen, nitrate nitrogen and nitrite nitrogen and organic nitrogen which is easy to decompose and simpler in part of organic matters. The ammonium nitrogen, nitrate nitrogen and nitrite nitrogen are core nitrogen forms in the soil, which influence plant growth and environmental risks, and the content of the ammonium nitrogen, the nitrate nitrogen and the nitrite nitrogen can directly reflect the nitrogen supply intensity and the state of the soil. Therefore, accurate measurement of the three nitrogen forms is important for evaluating the nitrogen supply capacity of soil, guiding scientific fertilization and preventing environmental pollution. At present, the main testing method of hydrolytic nitrogen in soil mainly comprises the following steps of measuring forest soil nitrogen (measuring hydrolytic nitrogen, LY/T1228-2015), hydrolyzing the soil by using 1.8mol/L sodium hydroxide, then placing a diffusion vessel in a 40 ℃ constant temperature box (24+/-0.5) for hours, taking out, titrating an ammonia-absorbed boric acid solution by using a standard hydrochloric acid solution, and calculating the hydrolytic nitrogen in the soil, wherein the hydrolytic nitrogen in the soil comprises ammonium nitrogen and nitrate nitrogen in the emphasis in local standard quick-acting soil nitrogen measurement (DB 13/T843-2007), and the soil is subjected to hydrolytic reduction in the presence of a strong alkali environment and ferrous sulfate, so that the easily hydrolytic nitrogen and nitrate nitrogen are converted into ammonia gas to be absorbed by the boric acid solution, and the ammonia in the absorption liquid is titrated by using standard acid. The method adopts an alkaline hydrolysis diffusion method, and has complicated steps as a whole, for example, a diffusion vessel needs to be subjected to alkaline hydrolysis in a constant temperature incubator for a long time to perform experiments, and the diffusion vessel also needs to be subjected to multiple operations such as boric acid absorption, hydrochloric acid titration and the like, so that the process is long, the problem of human operation errors is easily introduced in the titration process, and the parallelism and the accuracy of the experiments are poor. Disclosure of Invention The application aims to provide a rapid test method and application of hydrolytic nitrogen in soil, the method adopts pure water oscillation leaching, by adding the classified test on the existence form of the hydrolytic nitrogen, the rapid and accurate test on the hydrolytic nitrogen in the soil is realized. In order to achieve the above object, the present application provides the following solutions: in a first aspect, the application provides a method for rapidly testing hydrolytic nitrogen in soil, comprising: obtaining a soil sample, and processing the soil sample to obtain a dry soil sample; mixing the dried soil sample with ultrapure water, performing vibration extraction to obtain a soil mixed solution, and performing suction filtration and filtration treatment on the soil mixed solution to obtain a soil leaching solution; Dividing the soil leaching solution into a first test sample and a second test sample, carrying out water-soluble ammonia nitrogen test on the first test sample by a Navier reagent spectrophotometry to obtain water-soluble ammonia nitrogen content, and carrying out water-soluble nitrate nitrogen and water-soluble nitrite nitrogen test on the second test sample by an ion chromatography to obtain water-soluble nitrate nitrogen content and water-soluble nitrite nitrogen content; Obtaining a blank water-soluble ammonia nitrogen content value, a blank water-soluble nitrate nitrogen content value and a blank water-soluble nitrite nitrogen content value for blank control; Obtaining ammonia nitrogen hydrolytic nitrogen content, nitrate hydrolytic nitrogen content and nitrite hydrolytic nitrogen content based on the constant volume of the soil sample, the mass of the dry soil sample, the water-soluble ammonia nitrogen content, the blank water-soluble ammonia nitrogen content value, the water-soluble nitrate nitrogen content, the blank water-soluble nitrate nitrogen content value, the water-soluble nitrite nitrogen content and the blank water-soluble nitrite nitro