I d like to ask, how do you store your soil samples now, 20 or 80?

Hello! The method and temperature at which the soil sample is stored depends on the specific nature and use of the sample. In general, if you want to preserve soil samples for subsequent analysis, it is recommended to keep them in a dry, low-temperature, dark, and sterile environment.

Specifically, here are some common methods and temperatures for preserving soil samples:

1.Cryopreservation: Storing soil samples at a temperature of -20°C or lower can effectively prevent microbial activity and chemical reactions in the sample, thus maintaining the stability of the sample. This method is suitable for short-term storage of samples, e.g. not more than a few months.

2.Freeze-dried preservation: Freeze-drying soil samples can remove water from them, thereby reducing microbial activity and chemical reactions. This method is suitable for long-term storage of samples, such as several years or longer.

3.Vacuum-sealed preservation: Placing a soil sample in a sealed plastic bag or glass bottle to remove air from it can reduce the effect of oxygen on the sample and thus prolong the storage time of the sample. This method is suitable for short-term storage of samples, e.g. not more than a few months.

4.Special environment preservation: For some soil samples that need to be preserved in a special environment, such as soil samples in high altitude, high temperature and other environments, it is necessary to select the appropriate storage method and temperature according to the specific situation.

It is important to note that different storage methods and temperatures may have an impact on the properties and composition of soil samples, so it is necessary to choose the appropriate storage method according to the specific situation. In addition, care needs to be taken to avoid contamination and cross-contamination during storage.

Look what you want in the dirt! If you isolate bacteria, there is no way to store them, and it is best to collect them for immediate use. If you look at the heavy metals inside, you can make a filtrate and store it in a refrigerator at minus 20 degrees. Generally, soil samples are not directly preserved.

After the soil sample is collected, if it cannot be sent to a special laboratory for processing in time, the sample should be air-dried, that is, the collected soil sample should be spread out on a clean plastic sheet, and naturally air-dried in a ventilated, dry, avoid sunlight and not close to fertilizers and pesticides. When the sample is air-dried, one piece of label paper must be placed in the sample, and the other sheet of label paper and sample bag must be pressed with the sample and plastic sheeting. During the drying process, the soil sample should be turned frequently and the large soil clods should be crushed to speed up drying, and at the same time, intrusions other than the soil should be removed.

After the sample is dried, it is bagged according to the same method as sampling and bagging, and is to be sent to the laboratory unit for analysis and testing.

The air-dried soil samples are ground and sieved according to different analysis requirements, fully mixed, and then packed into sample bottles for later use. A label is placed inside and outside the bottle, indicating the number, sampling location, soil name, sampling depth, sample particle size, sampling date, sampler and sample preparation time, sample preparation person, etc. The prepared samples should be properly stored to avoid contamination by sunlight, high temperature, humidity and acid and alkali gases.

After all the analysis work is completed and the analysis data is verified, the sample is generally stored for 3 months to 1 year for inquiry. A small number of valuable samples that need to be stored for a long time should be stored in a jar and sealed with wax.

Some soil components such as ferric, nitrate, ammonium, etc., change significantly during the drying process and must be analysed with fresh samples. In order to truly reflect some physical and chemical properties of the soil in the natural state of the field, fresh samples should be sent back to the room for processing and analysis in time, and the samples should be mixed with coarse glass rods or plastic rods and quickly weighed for measurement. Fresh samples are generally not suitable for storage, if temporary storage is required, fresh samples can be packed into plastic bags, tightly tied to the mouth of the bag, and stored in the refrigerator or quick-frozen.

The various steps of soil conservation are very important, and the most critical step is the collection of soil samples.

Accurate collection of soil samples can ensure that the collected soil is representative, with little interference and little error. This is not only crucial for scientific research and understanding of landscape ecological processes, but also ensures the accuracy and reliability of subsequent soil analysis.

When collecting soil samples, it is necessary to prepare the chain segment and pay special attention to the following aspects:

1.Soil layers that are compatible with the purpose of the study should be selected and sampling should be carried out using sterile tools to avoid external contamination.

2.The collected soil samples should be properly preserved to avoid evaporation or other changes in their moisture. It is best to put the soil sample directly into a plastic bag and seal it to avoid the interference of air, moisture, cleanliness and other factors.

3.Before stock preservation, the soil sample should be air-dried or dried to achieve the desired moisture content to avoid deterioration and loss of its original properties.

Therefore, it can be said that the correct collection of soil samples is the most critical part of the whole soil preservation process, and only by strictly following the prescribed procedures can the accuracy and professionalism of the subsequent analysis be ensured.

1. The ice box used should only be packed in a fresh-keeping bag and placed in the ice box.

2. Refrigeration at 4 degrees can reduce cell reproduction and maintain the stability of the microflora. But low temperatures can also cause the death of certain microorganisms. So far, the effect of low temperature on the mortality rate of various microorganisms has not been studied, and it is not certain that it can indeed maintain the original microflora.

Therefore, samples should be analyzed as soon as possible after collection, and the shorter the storage time, the better.

3. Put the fresh soil sample in a test tube, plug it with cotton, and then seal it with kraft paper, remember to tie it tightly.