Method for measuring soil organic matter

Abstract

The invention relates to a method for measuring soil organic matter, which comprises the following steps: putting a soil sample into a dry triangular flask; adding a potassium dichromate sulfuric acidsolution with a preset molar concentration into the triangular flask; putting the triangular flask filled with mixed solution into a drying oven for heating; after heating, taking out and cooling thetriangular flask; adding a preset volume of distilled water to enable the volume of the mixed solution in the triangular flask to reach a preset volume; adding an o-phenanthroline ferrous indicator with the volume matched with the acidity of the mixed solution according to the acidity of the mixed solution; and titrating the mixed solution in the triangular flask by using a ferrous sulfate solution. Through heating by the drying oven, the risk of fire possibly occurring in the heating process of the oil bath can be avoided. The soil sample in the triangular flask is accurately heated at constant temperature, so that the heating temperature can be accurately controlled. The triangular flask is directly heated in the heating process, there is no need to transfer the soil sample from a testtube to the triangular flask, and the risk of harm to the human body and clothes caused by digestion liquid transfer is avoided.

Description

technical field [0001] The invention relates to the technical field of soil organic matter measurement, in particular to a method for measuring soil organic matter. Background technique [0002] At present, the determination of soil organic matter generally adopts the external heating method in oil bath. The oil bath external heating method uses a paraffin oil bath as an external heating source. Put the sample soil into a hard test tube, then add 10.00 mL of 0.4 mol / L potassium dichromate-sulfuric acid solution through a pipette, shake well and Put a glass funnel in each test tube mouth. Insert the test tubes into the wire cage one by one, and then immerse the wire cage in an oil bath heated to 185-190°C on an electric furnace, so that the liquid level in the test tube is lower than the oil level, and the temperature of the oil bath should drop to 170°C after putting it in. ~180°C, start timing when the solution in the test tube boils. At this moment, the temperature of th...

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Problems solved by technology

[0003] However, the oil bath external heating method has the following problems: 1. The risk of fire may occur during the heating process of the oil bath; 2. The risk of harm to the human body and its clothing due to the transfer of the cooking liquid; Difficult to control, resulting in the inaccurate determination of the cooking time, which is easy to cause errors, and the transfer of the cooking liquid will also cause errors

[0005] The technical solution in the above-mentioned patent is inconvenient to operate and takes a long time due to the need to preheat the oven

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