Preparation of Soil Sample
Involve the farmer in collection of soil sample:
A. Division of Field to Collect the Representative Samples:
For routine soil fertility testing, first traverse the filed to be sampled. Note variation in slope, colour, texture, management and cropping pattern. Demarcate the filed into uniform patches, each of which may be sample separately.
i) Do not Sample Unusual Area:
Avoid areas recently fertilized, old bunds, marshy spots near trees, compost heaps and other non-representative locations.
ii) Use Proper Sampling Tools:
Satisfactory samples can be taken with a soil tube augar spade, trowl, khurpi or pickaxe. Tools should be clean and free from fertilizer contamination.
iii) Use Other Accessories:
Bucket, information sheet, plastic or tarpaulin piece, cloth bag lables.
B) Collection of Soil Samples:
Remove organic debris, rocks and trash from the surface of the soil sampling areas before the sample is collected the soil sample to plough layer. Select the sampling spot in a zigzag manner from about 10-20 places. Collect all the samples in a bucker. Depth of sampling is desired according to the purpose.
1. Soil fertility (15-25 cm)
2. Salinity and alkalinity (1m)
3. Establishment of gardens (2m)
4. Soil survey profile of (1-1.5m ) depth
Keep record of the areas sampled and simple sketch map for reference.
C) Handling and Dispatch of Sample to Laboratories:
After complete collection of soil samples from field the organic residues like tree leaves, twings, dung etc and gravels , stones and other unwanted material should be kept out and sample should be prepared for laboratory analysis by adopting following steps.
The soil samples should be air dried first and then grinding should be followed. A wooden mortar and pastle should used for grinding to avoid contamination in the soil sample. After grinding soil samples should be sieved with 20-80 mesh sieve and all the samples are then mixed thoroughly by spreading over cloth or paper. From this bulk soil sample one representative soil sample should be collected following quartering method of portioning. About 250 to 500 g of soil sample is sufficient which should be stored in dry and clean poly bags, screw cap jars or card board boxes with proper labeling.