A useful soil testing service starts with the collection of representative soil samples. A fertilizer recommendation made after analyzing the soil cans is only as good as the sample on which it is based. Actually the one to ten grams of soil used for each chemical analysis should represent as accurately as possible the entire surface six inches of soil, weighing about 2 million pounds per acre. The importance of taking a representative composite sample is, therefore, self-evident. One field can be treated as a single sampling unit only if it is relatively uniform and does not exceed approximately five acres. Variations in slope, colour, texture, management, and cropping pattern should be taken into account and separate composite soil sample adequately representing the field, small portions of surface soil

should be collected to depth of six inches from at least ten well-distributed spots in the field, mixed well, and about ½ kg of representative sample sent to laboratory.
Proper sampling tools are essential for collection of good soil samples. For a soft, moist soil, the soil tube, phowda (spade), or khurpi (trowel) are usually quite satisfactory. For harder soils, a screw type auger, or an adze might be more convenient. Post hole augers are convenient for sampling excessively wet areas like paddy fields. An extension worker whose duties include collection of soil samples should be supplied with at least a few of these tools, and also a plastic bucket.The phowda, khurpi and adze are very common implements available in most hardware shops and so there should be no difficulty in procuring these implements.
The farmers should be given help in filling out the soil sample information sheet with an ex-plantation of any items not understood. It should be remembered that the information sheet is very vital part of procedures that go to make a good soil test recommendation. This sheet must supply all of the background information that, in combination with the results of the analysis, makes possible an accurate fertilizer recommendation for a certain crop, for that particular field. Factors such as crop variety, slope of land, irrigation and drainage facilities, and pervious cropping seasons affect the amounts of fertilizer to be applied to particular crop. Any peculiarities noted in the soil or in the vigor or the crop would be very valuable information on the soil sample information sheet as a basis for making an adequate fertilizer recommendation. In the absence of this information, the soil chemist must base his recommendation upon the soil test values alone, and more often than not the farmer will receive an adequate fertilizer recommendation.
Steps for Soil Collection

1. Sample each field separately. However, where the areas within a field differ distinctly in crop growth, appearance of the soils, or in elevation, or are known to have been cropped or fertilized and manured differently, divide the field and sample each area separately.
2. Take a composite sample from each area. Scrape away surface litter, and then take a small         sample from the surface to plough depth from a number of spots in the field (10 to 15 per acre).
3. Collect these samples in a clean bucket or some such wide container.
4. Where crops have been planted in lines (rows), sample between the lines.
5. Do not sample unusual area. Avoid areas recently fertilized, old bunds, and marshy spots, near    trees, compost piles, and other non-representative locations.
6. Take a uniform thick sample from the surface to plough depth. If a spade or a trowel is used, dig a v-shaped hole, then cut out a uniform thick slice of soil from bottom to top of the exposed soil face, collect the sample on the blade or in your hand and place it in the bucket.
7. Pour the soil from the bucket on a piece of clean cloth or paper and mix thoroughly, discard, by quartering, all but 1 to 2 lbs. of soil. Quartering may be done by mixing sample well, dividing it into four equal parts, then rejecting two opposite quarters, mixing the remaining two portions, again dividing into four parts and rejecting two opposite quarters, and so on. The sample should be dried in the shade for an hour or two before it goes into the cloth bag container.
8. Each cloth bag should be large enough to hold a pound or two of soil, and should be properly marked to identify the sample.
9. Fill out the soil sample information sheet for each sample. These forms may be sent separately to the laboratory or enclosed with the soil sample.
10. Address the samples to the Soil Chemist, Soil Testing Laboratory.
11. Keep a record of the areas sampled and a simple sketch map for reference when you get the soil test and fertilizers recommendation report from the soil testing laboratory.