the process of taking soil is called
Answers
ANALYTICAL TECHNIQUES FOR SOIL TESTING
Soil sampling, processing and storage
Soil sampling
Principle
Soil testing is an essential component of soil resource management. Each sample collected must be a true representative of the area being sampled. Utility of the results obtained from the laboratory analysis depends on the sampling precision. Hence, collection of large number of samples is advisable so that sample of desired size can be obtained by sub-sampling. In general, sampling is done at the rate of one sample for every two hectare area. However, at-least one sample should be collected for a maximum area of five hectares. For soil survey work, samples are collected from a soil profile representative to the soil of the surrounding area.
Materials required
1. Spade or auger (screw or tube or post hole type)
2. Khurpi
3. Core sampler
4. Sampling bags
5. Plastic tray or bucket
Points to be considered
Collect the soil sample during fallow period.
In the standing crop, collect samples between rows.
Sampling at several locations in a zig-zag pattern ensures homogeneity.
Fields, which are similar in appearance, production and past-management practices, can be grouped into a single sampling unit.
Collect separate samples from fields that differ in colour, slope, drainage, past management practices like liming, gypsum application, fertilization, cropping system etc.
Avoid sampling in dead furrows, wet spots, areas near main bund, trees, manure heaps and irrigation channels.
For shallow rooted crops, collect samples up to 15 cm depth. For deep rooted crops, collect samples up to 30 cm depth. For tree crops, collect profile samples.
Always collect the soil sample in presence of the farm owner who knows the farm better
Procedure
Divide the field into different homogenous units based on the visual observation and farmer’s experience.
Remove the surface litter at the sampling spot.
Drive the auger to a plough depth of 15 cm and draw the soil sample.
Collect at least 10 to 15 samples from each sampling unit and place in a bucket or tray.
If auger is not available, make a ‘V’ shaped cut to a depth of 15 cm in the sampling spot using spade.
Remove thick slices of soil from top to bottom of exposed face of the ‘V’ shaped cut and place in a clean container.
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