RU48453U1 - DEVICE FOR DETERMINING HUMUS CONTENT IN SOIL - Google Patents

Abstract

The utility model relates to equipment for agrochemical monitoring in agricultural production, in particular to devices for determining the physicochemical properties of soil in the analysis of organic matter and can be used in the field to determine soil fertility. The device is made in the form of a metal container with a screw cap with a volume of at least 100 cm ³ , freely entering into a larger thermostatic vessel with a tight-fitting lid. A through hole is provided in the center of both covers for fixing the thermometer. For a metal container, a replaceable lid is provided without a through hole for boiling in water. Thus, the device for determining humus in the soil allows in field conditions to reliably determine the percentage of humus from the time of heating of soil samples.

Description

The utility model relates to equipment for agrochemical monitoring in agricultural production, in particular to devices for determining the physicochemical properties of soil in the analysis of organic matter and can be used in the field to determine soil fertility.

Known chemical methods for the determination of humus in soil by the method of I.V. Tyurin (Agrochemical methods of soil research, Publishing House "Science", Moscow, 1965, - P. 45-51), based on the oxidation of organic matter of the soil with chromic acid to form carbon dioxide , as well as accelerated determination of the humus composition by the Kononova and Belchakova method (Agrochemical methods for soil research, Nauka Publishing House, Moscow, 1965, p. 51-58) using sodium pyrophosphate.

The disadvantages of these methods is that with a high content of humus (over 15-20%), the determination becomes unreliable due to incomplete oxidation of organic matter, and in the case of podzolic, sod-podzolic soils and red soils, where humus is more mobile than in chernozems and chestnut soils, possible changes in the organic part of the soil can also not be considered reliable.

The well-known "Method for the determination of humus" (RF patent No. 2020481.5 IPC, G 01 N 33/24, date of publication of the claims - 1994.09.30; patent holder - St. Petersburg State University), which consists in the effect of oxidizing agents of different oxidizing ability on a number of averaged soil samples, potassium dichromate solutions with the same concentration of 0.4 n are used as oxidizing agents. in the final volume and increasing oxidizing ability created through the use of a series of sulfuric acid solutions, the concentration of which in the final volume

is 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 vol.%. Also known is the “Method for evaluating soil fertility” (RF patent No. 2080771, 6 IPC, A 01 G 7/00, date of publication of the claims - 1997.06.10; patent holder - St. Petersburg State Agrarian University), which consists in the fact that they take samples specific soils in which physical clay content and actual parameters of the estimated fertility characteristics are determined by physicochemical analysis: pH, humus content, macro- and microelement content, arable layer thickness. As a reference soil, soil is taken that contains 20-50% of physical clay, and parameters corresponding to its potential fertility are set for the estimated characteristics of the reference soil. An assessment scale is constructed in which, relative to the reference soil, which is assigned the highest score, points are set for soils other in the content of physical clay, and the parameters of the potential fertility of the reference soil and the optimal parameters of the estimated characteristics of soil fertility with a specific number of points in the volume of the assessment scale are entered.

A common disadvantage of the proposed methods is their great complexity, the mandatory presence of a wide range of laboratory equipment and the technical impossibility of determining soil fertility in the field.

An analogue of the proposed device (prototype) is the "Method for determining the physicochemical properties of dispersed materials" (A. p. No. 1656424, MKI G 01 N 25/00, date of publication of the claims - 15.06.91; author - S.I. Linnik) based on the analysis of the physicochemical structure of dispersed materials using their thermophysical properties.

The disadvantage of this method is the lack of a device for its implementation.

The purpose of the utility model is to give portability to a device for determining the humus content in soil with an increase in the reliability of determination with any content of organic matter in the field.

For this purpose, the device is made in the form of a metal container with a screw cap with a volume of at least 100 cm ³ , freely entering a larger thermostatic vessel with a tight-fitting lid. A through hole is provided in the center of both covers for fixing the thermometer. A metal cover provides a replaceable lid without a through hole. By the time the heat pulse passes through the soil sample, a determination is made of the percentage of humus.

The drawing shows a device for determining the content of humus in the soil (Figure 1). The device consists of a metal container 1, onto which a small cover 2 with a through hole is screwed on using a threaded connection 3, as well as a replaceable cover 9 without a through hole. The metal container 1 is freely inserted into the larger thermostatted vessel 5, which is tightly closed by the large lid 6. In the small lid 2 and in the large lid 6 in the center there is an opening 7 for fixing the thermometer 8.

The principle of operation of the device in the field is as follows. A selected soil sample 4 with known moisture is placed in a metal container 1 and closed with a small cover 9. The soil sample in a metal container is placed in boiling water for 60 seconds, and then it is removed, a small cover 2 with a through hole is screwed and placed in a thermostatic vessel 5, and closed a large lid 6, in the center of which a thermometer is installed, passing through the through hole and fixed in the soil sample 4 of the metal container 1. The researcher records the time in seconds ogreva soil sample for 5, 10 and 15 degrees Celsius from the initial temperature. The composition and specific humus content in the soil sample are judged by the time the temperature rises. At the same soil sample moisture, the temperature increases by 5-15 degrees

Celsius occurs the faster, the lower the content of organic matter in the soil.

Example. We investigate chernozem soil samples with a total moisture content of 17-21%, taken from a depth of 5-10 cm, in the first case, on arable land, in the second case, next to it, from an unplowed meadow. We close the samples in a metal container, hold for 60 seconds in boiling water. We take out the metal container, put it in a thermostatically controlled vessel and measure the temperature using a thermometer passing through the through holes of the covers and fixed in the center of the soil sample. In the first case, the heating time of the soil sample by 5 degrees Celsius was 83 seconds, by 10 degrees Celsius - 104 seconds and 15 degrees Celsius - 121 seconds. In the second case, the warm-up time significantly increased and amounted to 141, 177 and 206 seconds, respectively. It can be concluded that the humus content in the second case is higher, which was confirmed by chemical analysis. In the first case, the humus content in the soil was 5.8%, in the second case, 6.5%. Using a series of experiments on soil samples (using leached chernozem as an example) of known moisture content and humus percentage, a heating time scale has been developed for this device and any soil humus content in the field is determined from it (Appendix 1).

Thus, the device for determining humus in the soil, made in the form of a metal container with a screw cap at least 100 cm ³ in volume, freely entering a larger thermostatic vessel with a tight-fitting lid, allows in field conditions to reliably determine the percentage humus content.

Annex 1

The heating time of soil samples with a total humidity of 17-21% from a depth of 5-10 cm on leached chernozem, depending on the percentage of humus (soil sample weight - 5 grams)

Humus content, Sample heating time, seconds interest 5 ° C heating 10 ° C heating 15 ° C heating 3.0 48 ± 2 60 ± 2 67 ± 2 3,5 51 ± 2 65 ± 2 74 ± 3 4.0 57 ± 2 71 ± 2 80 ± 3 4,5 63 ± 2 75 ± 2 89 ± 3 5.0 70 ± 3 81 ± 3 95 ± 3 5.5 75 ± 3 87 ± 3 105 ± 4 6.0 80 ± 3 99 ± 3 119A4 6.5 141 ± 5 176 ± 6 206 ± 7

Claims (4)

1. A device for determining humus in the soil, consisting of vessels of different volumes with covers, a thermometer, weights, a soil moisture meter, characterized in that the smaller vessel is made of metal, and the larger vessel is thick-walled in the form of a thermostat, with the cover the vessels have a through hole in the center. 2. The device according to claim 1, characterized in that the vessels are made freely entering one into the other. 3. The device according to claim 1, characterized in that the metal vessel is made with a volume of at least 100 cm ³ . 4. The device according to claim 2, characterized in that the metal vessel has an additional removable cover, made without a through hole.