Method for measuring evaporation resistance coefficient of medium-covered saline alkali soil surface

Abstract

The invention belongs to the technical field of soil evaporation capacity measurement, and particularly relates to a method for measuring the evaporation resistance coefficient of the surface of medium-covered saline alkali soil. According to the method, the weights of the bare saline-alkali soil and the medium-covered saline-alkali soil are weighed respectively, the surface evaporation resistance coefficient of the medium-covered saline-alkali soil is obtained through calculation according to a specific model, and a theoretical basis for medium type and thickness screening is provided for improving saline-alkali soil through a medium covering method, the calculation model of the medium covering saline alkali soil surface evaporation resistance coefficient is fn = (M0-Mn) / (G0-Gn). The method provided by the invention is simple to operate, the result is visual and visible, and in addition, the method shows good stability, reliability and accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of soil evaporation measurement, and in particular relates to a method for measuring the evaporation resistance coefficient of a medium-covered saline-alkali soil surface. Background Art

[0002] The moisture content in the soil can represent the current properties and capabilities of the soil and provide certain theoretical guidance for the growth of crops. For this reason, there are many studies on the measurement of moisture content in the soil, such as patent CN202453265U, patent CN106840955A, patent CN118136143A, etc., which all provide instruments or methods for measuring soil moisture evaporation. However, the existing instruments or methods for measuring soil moisture evaporation generally have the following problems: First, the precision of instruments used to weigh soil weight is low. In a short period of time, the evaporation of soil moisture is small, and the change in soil weight is not large, which is difficult to be reflected by the weighing instrument. However, if a weighing instrument with higher precision is used, the measurement cost will be too high. Second, the traditional soil evaporation method is used to calculate the adjacent weighing point weight loss method, that is, the weight of the soil before evaporation measured in the previous measurement is used as the calculation basis, and the next measurement value is subtracted from the previous one. However, in the actual experimental process, if the measurement is carried out in a natural environment, due to the interference of external factors such as wind, it is very easy to have the problem that the soil quality increases instead of decreases after a period of evaporation. Of course, in order to avoid this problem, the soil evaporation can be measured in a fully enclosed environment, but the result is that the fully enclosed environment has poor authenticity. Once it is put into a real natural environment, there will be a large error, and the accuracy will be worse. Third, when using the medium covering method to improve saline-alkali land, although the effects of various media on the improvement of saline-alkali land can be obtained by measuring the soil electrical conductivity, there has been no relevant research so far on how the water evaporation on the saline-alkali soil surface occurs after the medium is covered, and how to quickly and accurately compare the water evaporation on the saline-alkali soil surface after different medium coverings. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for determining the evaporation resistance coefficient of the surface of medium-covered saline-alkali soil.

[0004] The medium-covered saline-alkali soil surface evaporation resistance coefficient described in the present invention refers to: under the same external environmental conditions (same temperature, same humidity, same wind force), in the same time period, the ratio of the water evaporation of the same area of ​​bare saline-alkali soil to the water evaporation of the medium-covered saline-alkali soil surface, that is, the relative value of the water evaporation of the medium-covered saline-alkali soil surface to the water evaporation of the bare saline-alkali soil surface, so as to describe the speed of water evaporation on the saline-alkali soil surface after medium covering.

[0005] The present invention provides a method for determining the evaporation resistance coefficient of the surface of medium-covered saline-alkali soil, which specifically comprises the following steps: (1) Sampling: Place saline-alkali soil samples of the same weight, humidity and salinity in different sample boxes, and inject the same weight of water into each sample box. The amount of water injected is based on the saturation of the saline-alkali soil in the sample box. Three sample boxes form a group, one of which is used as a blank group, and the rest as experimental groups. The number of experimental groups is ≥1; (2) Cover the saline-alkali soil surface of each experimental group sample box in (1) with the medium. The three sample boxes in the same group have the same medium type and thickness, and the blank group is not covered with the medium. Weigh the sample boxes of each experimental group and the blank group for the first time and take the average value. The average weight of the sample boxes of each experimental group is recorded as G0, and the average weight of the sample boxes of the blank group is recorded as M0. (3) Place the sample boxes of each experimental group and blank group in (2) in an unobstructed and ventilated place and weigh them every 2 to 3 hours. The average weight of each experimental group is recorded as G1, G2-G n The average weights of the blank group sample boxes are recorded as M1, M2-M n , continuous testing for 12 to 20 days; (4) The data in (3) were processed using an automated data acquisition and analysis system to obtain the evaporation resistance coefficient of the saline-alkali soil surface after medium coverage in each experimental group; The evaporation resistance coefficient of the medium-covered saline-alkali soil surface is calculated using the following formula: Surface evaporation resistance coefficient f of medium-covered saline-alkali soil n = (M0-M n ) / (G0-G n ).

[0006] Preferably, the medium includes but is not limited to the following: fungus residue, reed powder residue, cotton stalk crushed residue, and fly ash residue.

[0007] Furthermore, the present invention also provides a system used in the above-mentioned determination method, wherein the system comprises: Sample boxes, wherein at least two groups of sample boxes are provided, and the number of sample boxes in each group is at least three; A weighing module, which is arranged directly below the sample box and is used to weigh the sample box. The weighing module is connected to the server via a data acquisition module. A data acquisition module is connected to the weighing module to receive weight data measured by the weighing module.

[0008] Preferably, the system further comprises an environment detection module, and the environment detection module is connected to the data acquisition module; The environment detection module includes any one or more of a wind speed detection unit, a temperature detection unit, and a humidity detection unit.

[0009] The beneficial effects of the present invention are: (1) A method and a model for determining the evaporation resistance coefficient of saline-alkali soil surface covered by a medium are provided. The calculation formula of the model is: The evaporation resistance coefficient of saline-alkali soil surface covered by a medium f n = (M0-M n ) / (G0-G n ), that is, by weighing the weight of the bare saline-alkali soil and the saline-alkali soil covered by the medium, the weight loss is calculated by taking the initial weighing point as the reference point for the weight loss calculation, and the calculation is performed according to the above-mentioned calculation model to obtain the change of the soil surface evaporation resistance coefficient value of the saline-alkali soil covered by the medium, thereby providing a theoretical basis for the screening of medium types and thicknesses for the medium method to improve saline-alkali land; (2) The method for determining the evaporation resistance coefficient of the medium-covered saline-alkali soil surface provided by the present invention not only has a simple operating system, but also provides more intuitive and clearer measurement results. In addition, the method exhibits good stability, reliability and accuracy, and avoids the interference of changes in external conditions such as wind force on weighing in a short period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram of a system for measuring the evaporation resistance coefficient of a medium-covered saline-alkali soil surface provided by the present invention; Figure 2 The change of the average wind speed value collected in Example 1 of the present invention; Figure 3 The temperature average value change collected in Example 1 of the present invention; Figure 4 The average weight loss of saline-alkali soil in Group I, i.e., the blank group, in Example 1 of the present invention; Figure 5 The average weight loss of saline-alkali soil in Experimental Group II of Example 1 of the present invention; Figure 6The change of the evaporation resistance coefficient of the saline-alkali soil surface after being covered with fly ash in Experimental Group II of Example 1 of the present invention; Figure 7 Changes in the evaporation resistance coefficient of the saline-alkali soil surface after covering the fungus residue in Experimental Group III of Example 1 of the present invention; Figure 8 This is the change of the evaporation resistance coefficient of the saline-alkali soil surface after covering the switchgrass residue in Experimental Group IV of Example 1 of the present invention; Fig. 9 The change of the evaporation resistance coefficient of the saline-alkali soil surface after the experimental group V of Example 1 of the present invention was covered with cotton stalk residue; Fig.10 The average weight loss change of Group 1, i.e., the blank group, in Example 2 of the present invention; Fig.11 The change of the evaporation resistance coefficient of the saline-alkali soil surface after covering with 2 cm of medium in Experimental Group II of Example 2 of the present invention; Fig.12 The change of the evaporation resistance coefficient of the saline-alkali soil surface after covering with 4 cm of medium in Experimental Group III of Example 2 of the present invention; Fig.13 The change of the evaporation resistance coefficient of the saline-alkali soil surface after covering 6 cm of medium in Experimental Group IV of Example 2 of the present invention; Fig.14 This is the change of the evaporation resistance coefficient of the saline-alkali soil surface after the experimental group V of Example 2 of the present invention is covered with 10 cm of medium; Fig.15 The average weight loss of saline-alkali soil in Group I, i.e., the blank group, in Comparative Example 1 of the present invention; Fig.16 This is the change of the evaporation resistance coefficient of the saline-alkali soil surface after being covered with fly ash in Experimental Group II of Comparative Example 1 of the present invention; Fig.17 The average weight loss of saline-alkali soil in Group I, i.e., the blank group, in Comparative Example 2 of the present invention; Fig.18 This is the change of the evaporation resistance coefficient of the saline-alkali soil surface after the experimental group II of comparative example 2 of the present invention is covered with 2 cm of medium. DETAILED DESCRIPTION

[0011] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0012] Example 1 This embodiment focuses on exploring the evaporation speed of water in saline-alkali soil after covering the saline-alkali soil with different types of media, and uses the system to measure the evaporation resistance coefficient of the saline-alkali soil surface covered with different types of media, thereby providing basic data and optional media types for improving saline-alkali land.

[0013] The specific operations of this embodiment are as follows: (1) Sampling: Place saline-alkali surface soil samples of the same weight, humidity and salinity in different sample boxes, covered with dark felt. The thickness of the saline-alkali soil in the sample boxes is 24 cm. Inject the same weight of water into each sample box. The amount of water injected is based on the saturation of the saline-alkali soil in the sample box. Three sample boxes form a group, one of which is used as a blank group, and the rest as experimental groups; (2) The dry medium was respectively covered on the upper surface of the saline-alkali soil in the sample boxes of each experimental group in (1), with the thickness of the medium being 5 cm. Specifically: in Group I, sample boxes 1-3 were bare soil and not covered with medium, serving as the blank group; in Group II, sample boxes 4-6 were covered with fly ash as the upper surface of the saline-alkali soil; in Group III, sample boxes 7-9 were covered with fungus residue as the upper surface of the saline-alkali soil; in Group IV, sample boxes 10-12 were covered with switchgrass residue as the upper surface of the saline-alkali soil; and in Group V, sample boxes 13-15 were covered with cotton stalk residue as the upper surface of the saline-alkali soil.

[0014] Moreover, the media types in the three sample boxes in the same group were the same; The sample boxes in each experimental group and blank group were weighed for the first time to obtain the average weight. The average weight of the sample boxes in each experimental group was recorded as G0, and the average weight of the sample boxes in the blank group was recorded as M0; (3) Place the sample boxes of each experimental group and the blank group in (2) in an unobstructed and ventilated place and weigh them every 2 to 3 hours. The average weight of each experimental group is recorded as G2, G3, G4, ... G n The average weights of the blank sample boxes are recorded as M2, M3, M4, ... n , the test time is from 9:30 on September 22 to 9:30 on October 9; (4) The data in (3) were processed using a data acquisition and analysis system to obtain the evaporation resistance coefficient of the saline-alkali soil surface after medium coverage in each experimental group.

[0015] In this embodiment, the evaporation resistance coefficient of the medium covering the surface of the saline-alkali soil is calculated using the following formula: The evaporation resistance coefficient of the medium-covered saline-alkali soil surface is f1=(M0-M1) / (G0-G1), f2=(M0-M2) / (G0-G2)……f n = (M0-M n ) / (G0-G n ).

[0016] During the detection process of this embodiment, the change of the average wind speed collected by the wind speed sensor is shown in the attached Figure 1The changes in the average temperature values ​​collected by the temperature sensor are shown in the attached Figure 2 shown.

[0017] It can be seen that in the actual detection process, the external environment including wind speed, temperature, etc. are constantly changing, and these external factors will inevitably have a direct impact on the evaporation speed of water on the soil surface, and may cause errors in weighing during the detection process, resulting in the latter weighing value being larger than the previous weighing value.

[0018] Furthermore, in this embodiment, the weight value of the saline-alkali soil covered by the medium of each experimental group is first obtained by the data acquisition system, and the average weight of each group of 3 sample boxes is obtained by calculation through the computer data processing system. The calculation is performed according to the above-mentioned calculation formula for the surface evaporation resistance coefficient of the saline-alkali soil covered by the medium. In particular, when calculating the weight loss, the weight of the initial point, that is, the weight of the first measurement point, is used as a reference, and each weight loss is subtracted from the weight of the point to obtain the surface evaporation resistance coefficient value of the saline-alkali soil covered by the medium.

[0019] In addition, since the amount of data collected by the online data collection system of the present invention is very large and needs to go through a complex calculation process, in order to better illustrate the experimental effect of the present invention, only the final processed experimental result diagram is attached here.

[0020] Attached Figure 3 The average weight loss of three sample boxes in Group I, i.e., the blank group, in which only saline-alkali soil without covering medium was added, is shown.

[0021] Attached Figure 3 It can be seen that when the initial weight is taken as the starting point of weight loss, the weight loss of the obtained sample boxes shows obvious regularity.

[0022] In addition, Figure 4 , Attachment Figure 5 The average weight loss of the experimental group II with fly ash added and the surface evaporation resistance coefficient of the saline-alkali soil covered with fly ash are shown respectively.

[0023] Attached Figure 4-5 It shows that when the medium covering the surface of saline-alkali soil is inorganic medium fly ash, the surface evaporation resistance coefficient of the saline-alkali soil is less than 1, that is, the evaporation rate of water on the surface of the saline-alkali soil is accelerated after covering with fly ash. The possible reasons for this phenomenon are: the fly ash particle size is relatively fine, at the micron level, and the coverage of fly ash continues the capillary phenomenon of the saline-alkali soil. In addition, the fly ash particles are loose and porous, and these ultra-fine pores also amplify the capillary phenomenon, causing the coverage of fly ash to aggravate the capillary phenomenon of the saline-alkali soil.

[0024] In addition, Figure 6-8The evaporation resistance coefficients of the saline-alkali soil surfaces after being covered with different media in experimental groups III to V are shown respectively. The figure can intuitively show the changes in the evaporation resistance coefficients of the saline-alkali soil surfaces of each group, and the soil evaporation resistance coefficients show a strong regularity.

[0025] Furthermore, the experimental results show that when plant residue or fungus residue is used as a medium to cover the surface of saline-alkali soil, the evaporation resistance coefficient of the saline-alkali soil surface is not closely related to the specific medium type, and, except for the fly ash group, at the beginning of the experiment, the resistance coefficient near the original starting point is elevated. This is because the first thing that evaporates from the soil is the surface water, so a high point appears. Based on this, in the subsequent improvement of saline-alkali land, water can be irrigated first, and the medium can be laid after the evaporation resistance coefficient has reached the high point, avoiding the illusion caused by the evaporation of surface water.

[0026] Example 2 This embodiment focuses on exploring the evaporation speed of water in saline-alkali soil when the saline-alkali soil is covered with the same medium of different thicknesses. The system is used to measure the influence of the covering thickness of the medium on the evaporation resistance coefficient of the saline-alkali soil surface, thereby providing basic data and optional medium thickness for improving saline-alkali land. The measurement time of this embodiment is August 30, 2024 to September 14, 2024.

[0027] The operation of this embodiment is different from that of Embodiment 1 in that: In (2), the upper surface of the saline-alkali soil in the sample boxes of each experimental group in (1) was covered with the same dry medium, i.e., fungus residue, with different thicknesses of the medium. Specifically, the saline-alkali soil in sample boxes No. 1-3 of Group I was not covered with a medium, serving as a blank group; the upper surface of the saline-alkali soil in sample boxes No. 4-6 of Group II was covered with a medium with a thickness of 2 cm; the upper surface of the saline-alkali soil in sample boxes No. 7-9 of Group III was covered with a medium with a thickness of 4 cm; the upper surface of the saline-alkali soil in sample boxes No. 10-12 of Group IV was covered with a medium with a thickness of 6 cm; and the upper surface of the saline-alkali soil in sample boxes No. 13-15 of Group V was covered with a medium with a thickness of 10 cm.

[0028] In this embodiment, the evaporation resistance coefficient of the saline-alkali soil surface after covering with the medium is calculated using the same formula as in Example 1.

[0029] Attached Fig. 9 -Attached Fig.13 The average weight loss of saline-alkali soil in the blank group and the evaporation resistance coefficient of the saline-alkali soil surface covered with different thicknesses of media in each experimental group are shown respectively. The result graphs are intuitive and clearly visible. The results show that the evaporation resistance coefficient of the saline-alkali soil surface covered with media is related to the thickness of the medium covering the saline-alkali soil surface, and with the increase of the medium thickness, the evaporation resistance coefficient of the soil surface increases slightly, but no linear correlation is shown.

[0030] Comparative Example 1 The difference from Example 1 is that the calculation method of the evaporation resistance coefficient of the medium-covered saline-alkali soil surface is different.

[0031] This comparative example uses the following formula to calculate the evaporation resistance coefficient of the saline-alkali soil surface: f1=△M / △G=(M0-M1) / (G0-G1)、f2=(M1-M2) / (G1-G2)……f n =(M n-1 -M n ) / (G n-1 -G n ).

[0032] That is, the weight loss is calculated based on the weight of the sample box at the last measurement point, rather than the weight at the initial point.

[0033] The average weight loss of the blank group, i.e., Group I, obtained by using the calculation model of this comparative example is shown in the attached Fig.14 .

[0034] In addition, Fig.15 The evaporation resistance coefficient of the saline-alkali soil surface after covering with medium in experimental group II is shown.

[0035] Comparative Example 2 The difference from Example 2 is that the calculation method of the evaporation resistance coefficient of the medium-covered saline-alkali soil surface is different.

[0036] In this comparative example, the formula used in calculating the evaporation resistance coefficient of the medium-covered saline-alkali soil surface is the same as that of comparative example 1.

[0037] That is, the weight loss is calculated based on the weight of the sample box at the last measurement point, rather than the weight at the initial point.

[0038] The average weight loss of the blank group, i.e., Group I, obtained by using the calculation model of this comparative example is shown in the attached Fig.16 .

[0039] In addition, Fig.17 It shows the change of evaporation resistance coefficient on the saline-alkali soil surface after medium covering in experimental group II.

[0040] Comparing the experimental results of Comparative Example 1-2 with those of Example 1-2, the difference is significant.

[0041] By comparison, it can be seen that the method of calculating the evaporation resistance coefficient of the surface of the medium-covered saline-alkali soil using the model of Examples 1-2 of the present invention shows better stability, and the regularity of the experimental results is obvious and more intuitive. However, in Comparative Examples 1-2, the model using the weight obtained last time as the reference point for weight loss calculation has a weak regularity in the evaporation resistance coefficient of the surface of the medium-covered saline-alkali soil, and the model is easily affected by external environmental factors such as wind force, and there is a large error, and the reference of the experimental results is poor.

Claims

1. A method for determining the evaporation resistance coefficient of medium-covered saline-alkali soil surface, characterized in that: The evaporation resistance coefficient of the medium-covered saline-alkali soil surface is the ratio of the evaporation of water in the exposed saline-alkali soil of the same area to the evaporation of water in the medium-covered saline-alkali soil under the same external environmental conditions and in the same time period; The method comprises the following steps: (1) Sampling: Place saline-alkali soil samples of the same weight, humidity and salinity in different sample boxes, and inject the same weight of water into each sample box. The amount of water injected is based on the saturation of the saline-alkali soil in the sample box. Three sample boxes form a group, one of which is used as a blank group, and the rest as experimental groups. The number of experimental groups is ≥1; (2) Cover the saline-alkali soil surface of each experimental group sample box in (1) with the medium. The three sample boxes in the same group have the same medium type and thickness, and the blank group is not covered with the medium. Weigh the sample boxes of each experimental group and the blank group for the first time and take the average value. The average weight of the sample boxes of each experimental group is recorded as G0, and the average weight of the sample boxes of the blank group is recorded as M0. (3) Place the sample boxes of each experimental group and blank group in (2) in an unobstructed and ventilated place and weigh them every 2 to 3 hours. The average weight of each experimental group is recorded as G1, G2-G n The average weights of the blank group sample boxes are recorded as M1, M2-M n , continuous testing for 12 to 20 days; (4) The data in (3) were processed using an automated data acquisition and analysis system to obtain the evaporation resistance coefficient of the saline-alkali soil surface after medium coverage in each experimental group; The evaporation resistance coefficient of the medium-covered saline-alkali soil surface is calculated using the following formula: Surface evaporation resistance coefficient f of medium-covered saline-alkali soil n = (M0-M n ) / (G0-G n ).

2. The method for determining the evaporation resistance coefficient of a medium-covered saline-alkali soil surface as claimed in claim 1, characterized in that: The medium includes but is not limited to the following: fungus residue, reed powder residue, cotton stalk crushed residue, and fly ash residue.

3. The system used in the determination method according to claim 1, characterized in that: include: Sample boxes, wherein at least two groups of sample boxes are provided, and the number of sample boxes in each group is at least three; A weighing module, which is arranged directly below the sample box and is used to weigh the sample box. The weighing module is connected to the server via a data acquisition module. A data acquisition module is connected to the weighing module to receive weight data measured by the weighing module.

4. The system according to claim 3, characterized in that The system further comprises an environment detection module, and the environment detection module is connected to the data acquisition module; The environment detection module includes any one or more of a wind speed detection unit, a temperature detection unit, and a humidity detection unit.

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