Soil Sampling protocol

Author

Amrinder Jakhar

1 Materials Required:

  • Soil sampler

  • 10-liter buckets (2)

  • Spatula or soil-removing tool

  • Paper bags

  • Rubber bands

  • Plastic tub

  • WD-40 (for lubrication of soil sampler)

2 Before going to the field:

  1. Check the weather forecast to ensure that the field is dry enough for sampling. If it rains, the soil may be too wet, which can affect the quality of the soil samples.

  2. Label paper bags properly and arrange them in bundles according to the sampling blocks. This will help you keep track of the samples and avoid confusion later on.

  3. Our bag labels should include:

  • Study year and name
  • Date
  • Plot number
  • Depth
Label example

2023 Corn split
March 15
101
0-15 cm

3 Sampling in the field:

  1. Remove any debris or vegetation from the soil surface to ensure that the sample is representative of the underlying soil.

  2. Place the bucket in the plot you want to sample. If you are taking samples at different depths, place paper bags in the different buckets according to soil depth to avoid confusion later on.

  3. Take a soil sample using the soil sampler from 0-30 cm depth. Remove the lower 15 cm of soil using a spatula or a tool and place soil in the bucket of 16-30 cm depth, and the above soil in the other bucket. Repeat this process to collect 8-10 more soil samples randomly throughout the plot to make a composite sample.

  4. Once you collect 8-10 soil samples, thoroughly mix the soil in the bucket and transfer enough soil into the paper for that depth to fill half of the bag.

  5. Check the label on the bag that everything is right such as date of sampling, plot number, depth, and any other relevant information such as soil type, and vegetation cover.

  6. Fold the bag from top to close the bag, and wrap a rubber band around it.

  7. Clean the buckets and soil sampler before moving to a new plot. If soil is sticking to the auger, use WD-40 for lubrication.

4 After soil collection:

  1. Pack soil bags properly so the soil cannot fall out. Put them in the plastic tub to avoid any moisture contamination during transportation.

  2. Open the paper bags once you reach the lab for air drying. Soil bags can break due to moisture, which can lead to the mixing of soil samples.

  3. Let the soil air dry for a week in a cool, dry place. Do not expose the samples to direct sunlight or store them in areas with high humidity. Once the soil samples are dry, pack them and send them to the lab for analysis.

  4. Store the remaining samples in a cool, dry place until your study ends or you receive results from the lab and is satisfied with the report. Avoid storing them in direct sunlight or in areas with high humidity. Also, keep the samples organized and labeled properly for easy retrieval and future reference.