A method for preparing filtrate by volume method for soil testing

Abstract

The present invention discloses a method for preparing filtrate for soil testing by volume method, comprising the following steps: S1, artificially observing the hardness of the soil to which the soil sample belongs to, and obtaining soil sample hardness data; S2, performing pretreatment operation on the soil sample to be tested; S3, testing the testing index of the soil sample to be tested; S4, calculating the CEC value of the soil to which the soil sample belongs to; S5, testing the pH value of the soil sample to be tested; S6, testing the EC value of the soil sample to be tested; S7, testing the nitrate nitrogen value of the soil sample to be tested. The present invention first artificially observes the hardness of the soil to which the soil sample belongs to, and then obtains the filtrate of the soil sample to be tested by volume method according to the soil hardness data, and the testing index of the soil sample to be tested can be obtained according to the filtrate; at the same time, the pH value, EC value and nitrate nitrogen value of the soil sample to be tested are tested according to the volume method, and finally the content of various nutrients in the soil sample to be tested is obtained.

Description

Technical Field

[0001] The invention relates to the field of soil sample detection, and in particular to a method for preparing filtrate by volumetric method for soil detection. Background Art

[0002] The most important part of crop planting is fertilization. Scientific fertilization plays a key role in the success of planting. Before fertilization, the soil will be tested to confirm the current content of nutrients in the soil and the soil pH value, CEC value, and EC value. According to the nutritional needs of different crops and the soil CEC value (soil fertility retention capacity), the upper and lower limits of soil fertilization are determined, and the corresponding fertilizer ratio is made.

[0003] At present, the domestic soil nutrient element detection is carried out by weight method, that is, the method of detecting how many mg of nutrients are contained in 100g of air-dried soil, and then the corresponding fertilizer is matched according to the test results. However, the roots of plants are distributed in a certain volume of soil, and there are differences in the content of nutrients per unit volume of combined soil and loose soil. The weight method soil detection data cannot accurately meet the needs of plant roots distributed in a certain volume to absorb nutrients. With the vigorous promotion of organic fertilizers, the hardness of my country's soil will change greatly, from very hard soil to relatively hard, and then to loose soil samples. When the same 100g is used for testing hard soil and loose soil, the amount of soil volume required is different. In order to achieve the same weight, the soft soil needs to take a correspondingly large volume of soil sample for testing. The current agricultural operation is carried out in the following way: after applying a fixed weight of fertilizer to one acre of land, the soil is tilled 20-30cm, and then ridges are formed to plant crops. One acre of land is a concept of surface area. After 20-30cm of soil is tilled, it becomes a concept of volume. Therefore, the amount of fertilizer applied corresponds to 667m 2 The volume of rotary tillage is 20-30cm. Therefore, the amount of fertilizer contained in the unit volume is the same. When the sampling volume is large, the corresponding test value will become higher, so the test result of the weight method cannot accurately indicate the content of nutrients in the soil.

[0004] The amount of fertilizer applied to the soil is first determined by the soil CEC value, EC value and pH value. The upper and lower limits of soil fertilization are determined according to the soil's fertility retention capacity to ensure the continuous nutritional needs of plants, avoid the loss of fertilizers, and avoid the harm of excessive elements to plants. Soil test data without CEC values ​​is meaningless. The final destination of soil test data is to serve the fertilization design plan and is a reference value for soil conditions. Usually, when we say how much fertilizer is applied per acre of land, it is actually how much fertilizer we need to apply per unit volume. When testing soil nutrient elements, we directly perform volumetric testing, that is, test how many mg of nutrients are contained in 100cc of soil, and give fertilization recommendations directly based on the data tested by the volumetric method. This is a reasonable testing method to adapt to the soil that becomes softer year by year. Therefore, it is necessary to study a method for testing soil by volumetric method to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing filtrate by volume for soil testing, which is simple to operate and more suitable for soil characteristics, in order to solve the above problems.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A method for preparing filtrate for soil testing by volumetric method comprises the following steps:

[0008] S1. Obtain soil sample hardness data according to the hardness of the soil to which the soil sample belongs;

[0009] S2. Perform pretreatment operations on the soil samples to be inspected;

[0010] S3. Testing the test indicators of the soil samples submitted for testing;

[0011] S4. Calculate the CEC value of the soil to which the sample belongs based on the content and distribution of Ca, Mg, and K;

[0012] S5. Testing the pH value of the soil sample;

[0013] S6. Detect the EC value of the soil sample;

[0014] S7. Test the nitrate nitrogen value of the soil samples.

[0015] Furthermore, in step S3, the detection indicators of the soil sample to be inspected include an ammonium nitrogen index, a disposable phosphorus index, an exchangeable calcium index, an exchangeable magnesium index, an exchangeable potassium index, a disposable iron index, an exchangeable manganese index, and a sodium chloride index.

[0016] Furthermore, in step S3, detecting the detection index includes the following steps:

[0017] S31, add 20 ml of component extract to the filter;

[0018] S32, take 2cc of the soil sample for inspection with a soil spoon, and manually press the soil sample to make the hardness data of the soil sample in the soil spoon consistent with the hardness data of the soil sample obtained in step S1;

[0019] S33, adding 2cc of the soil sample in the soil spoon to the soil extract, mixing evenly and filtering to obtain the index filtrate;

[0020] S34. Add reagents corresponding to the detection indicators to the indicator filtrate for reaction. After the reaction, read the data with an identification instrument to obtain the detection indicators of the soil sample to be tested.

[0021] Furthermore, in step S5, detecting the pH value includes the following steps:

[0022] S51. Mark a first scale line and a second scale line on the test tube, wherein the volume ratio of the first scale line to the second scale line is 1:2.5;

[0023] S52, add the soil sample to be tested into the test tube to the first scale line;

[0024] S53, continue to add water into the test tube until the water level reaches the second scale line;

[0025] S54. After standing and stratifying, use a pH meter to test and obtain the pH value of the soil sample.

[0026] Furthermore, in step S6, detecting the EC value includes the following steps:

[0027] S61. Add water to the graduated flask to the 50 ml mark;

[0028] S62. Add the soil sample to be tested into the flask and mix the liquid in the flask to the 60 ml mark;

[0029] S63. After standing and stratifying, use an EC detector to test and obtain the EC value of the soil sample.

[0030] Furthermore, in step S7, detecting the nitrate nitrogen value includes the following steps:

[0031] S71. Add water to the graduated flask to the 60 ml mark.

[0032] S72. Add the soil sample to be tested into the flask and mix the liquid in the flask to the 70 ml mark;

[0033] S73. After standing and stratifying, use a nitrate nitrogen meter to test and obtain the nitrate nitrogen value of the soil sample.

[0034] Compared with the prior art, the present invention has the following advantages and positive effects:

[0035] The present invention first detects the hardness of the soil to which the soil sample to be inspected belongs, and then obtains the filtrate of the soil sample to be inspected by a volume method according to the soil hardness data, and the detection index of the soil sample to be inspected can be obtained according to the filtrate; at the same time, the pH value, EC value and nitrate nitrogen value of the soil sample to be inspected are detected according to the volume method, and finally the content of various nutrients in the soil sample to be inspected is obtained; the volume method is used for the detection operation throughout the process, the method is simple, and it can be operated in the field, and the nutrient content in the soil can be measured more accurately, providing a precise reference basis for the scientific planting of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 It is the framework logic diagram of the present invention. Implementation

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0039] like Figure 1 As shown, this embodiment discloses a method for preparing filtrate by volume method for soil testing, which detects the content of nutrients in the soil by selecting the volume method; firstly, the hardness of the field soil to which the soil sample to be tested belongs is tested, and then the soil sample to be tested is pretreated;

[0040] Then, based on the content and distribution of Ca, Mg, and K, the CEC value of the soil to which the sample belongs is calculated;

[0041] Finally, the corresponding soil filtrate is prepared according to different detection indicators, and the detection data is obtained by detecting the filtrate.

[0042] The entire soil testing process requires the preparation of four types of filtrates, depending on the test content;

[0043] The first type: detects 8 indicators including ammonium nitrogen, available phosphorus, exchangeable calcium, exchangeable magnesium, exchangeable potassium, available iron, exchangeable manganese and sodium chloride; the filtrate is prepared by first putting in 20ml of component extract, and then using a soil spoon to take 2cc of soil sample and add it to the component extract. The key point is to manually press the soil sample to make the hardness of the soil in the soil spoon consistent with that of the tested field soil, then mix and filter, add the reagents corresponding to each test item to the filtrate for reaction, and use the identifier to read the data.

[0044] The second method: testing the pH value; first prepare a specific test tube with two horizontal lines on it. The volume ratio of the two horizontal lines is 1:2.5. The filtrate is prepared by first adding soil to the first horizontal line, and then adding water to the second horizontal line. After the mixture is allowed to stand and stratify, it is tested with a pH meter. In the national standard method, the weight ratio of water to soil is 1:2.5. Although our volume is also 1:2.5, the weight ratio of water to soil becomes 1:3-5 during the process of adding water to soil. The ratio varies depending on the soil.

[0045] The third method: testing the EC value; the filtrate is prepared by first adding water to a flask with a scale to the 50ml mark, then adding the soil sample to be tested to the flask, and mixing the liquid in the flask to the 60ml mark. After the mixture is allowed to stand and separate into layers, it is tested with an EC instrument; in the national standard method, the weight ratio of water to soil is 5:1. We add 50ml of water to the 60ml mark with soil. Although the volume ratio is also 5:1, the weight ratio of water and soil changes in the process of adding soil to water. The ratio varies depending on the soil.

[0046] The fourth method: detecting the nitrate nitrogen value; the filtrate is prepared by first preparing a bottle with a scale, adding water to 60ml, and then adding soil to the 70ml scale line, mixing and letting stand to separate the layers, and then testing with a nitrate nitrogen meter; the filtrate is also prepared by the volumetric method.

[0047] The following table shows the nutrient content data of 20 soil samples collected from relatively soft fields such as rice fields and vegetable fields, obtained by weight method and volume method and tested by analytical instruments;

[0048] Serial number mg / 100g mg / 100cc 1 46.5 25 2 58.5 30 3 50.6 30 4 40.3 20 5 27.5 15 6 62.1 35 7 37.4 25 8 61.3 25 9 43.1 25 10 77.8 35 11 64.6 30 12 57.8 30 13 55.1 30 14 46.2 25 15 47.5 25 16 59.8 25 17 33.5 20 18 71.3 30 19 45.8 30 20 29.6 15

[0049] From the data in the table, it can be seen that when other conditions such as analytical instruments, extraction methods, color development, absorbance, etc. are the same, the value detected by the weight method is nearly twice the value detected by the volume method; that is, when calculating the amount of fertilizer applied, the amount of fertilizer applied after the weight method test is half of the amount applied after the volume method test. Therefore, when the weight method test data is used as the basis for soft land, the fertilization design will cause fertilizer deficiency, which will seriously affect the growth quality and yield of crops.

[0050] The present invention firstly observes the hardness of the soil to which the soil sample belongs, and then obtains the filtrate of the soil sample according to the soil hardness by the volume method, and obtains the detection index of the soil sample according to the filtrate; at the same time, the pH value, EC value and nitrate nitrogen value of the soil sample are detected according to the volume method, and finally the content of various nutrients in the soil sample is obtained; the volume method is used for the detection operation throughout the whole process, and the content of nutrients in the soil can be measured more accurately, providing an accurate reference basis for the scientific planting of crops.

Claims

1. A method for preparing filtrate for soil testing by volumetric method, characterized in that: The following steps are involved: S1. Obtain soil sample hardness data according to the hardness of the soil to which the soil sample belongs; S2. Perform pretreatment on the soil sample to be inspected, i.e. restore the hardness of the soil after sampling to make it the same as the hardness of the soil mentioned above, and measure a certain volume of soil sample; and control the water-soil volume ratio to be 5:1 when preparing the filtrate; S3. Test the test indicators of the soil samples sent for inspection. It includes the following steps: S31, add 20 ml of component extract to the filter; S32, take 2cc of the soil sample for inspection with a soil spoon, and manually press the soil sample to make the hardness data of the soil sample in the soil spoon consistent with the hardness data of the soil sample obtained in step S1; S33, adding 2cc of the soil sample in the soil spoon to the soil extract, mixing evenly and filtering to obtain the index filtrate; S34, adding reagents corresponding to the detection indicators to the indicator filtrate for reaction, and reading the data with an identification instrument after the reaction to obtain the detection indicators of the soil sample to be inspected; S4. Calculate the CEC value of the soil to which the sample belongs based on the content and distribution of Ca, Mg, and K; S5. Testing the pH value of the soil sample; S6. Detect the EC value of the soil sample; S7. Test the nitrate nitrogen value of the soil samples.

2. The method for preparing filtrate for soil testing by volumetric method according to claim 1, characterized in that: In step S3, the detection indicators of the soil sample to be inspected include an ammonium nitrogen index, an available phosphorus index, an exchangeable calcium index, an exchangeable magnesium index, an exchangeable potassium index, an available iron index, an exchangeable manganese index, and a sodium chloride index.

3. The method for preparing filtrate for soil testing by volumetric method according to claim 1, characterized in that: In step S5, detecting the pH value comprises the following steps: S51. Mark a first scale line and a second scale line on the test tube, wherein the volume ratio of the first scale line to the second scale line is 1:2.5; S52, add the soil sample to be tested into the test tube to the first scale line; S53, continue to add water into the test tube until the water level reaches the second scale line; S54. After standing and stratifying, use a pH meter to test and obtain the pH value of the soil sample.

4. The method for preparing filtrate for soil testing by volumetric method according to claim 1, characterized in that: In step S6, detecting the EC value includes the following steps: S61. Add water to the graduated flask to the 50 ml mark; S62. Add the soil sample to be tested into the flask and mix the liquid in the flask to the 60ml mark; S63. After standing and stratifying, use an EC detector to test and obtain the EC value of the soil sample.

5. The method for preparing filtrate for soil testing by volumetric method according to claim 1, characterized in that: In step S7, detecting the nitrate nitrogen value comprises the following steps: S71. Add water to the graduated flask to the 60 ml mark. S72. Add the soil sample to be tested into the flask and mix the liquid in the flask to the 70 ml mark; S73. After standing and stratifying, use a nitrate nitrogen meter to test and obtain the nitrate nitrogen value of the soil sample.

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