Soil Test Methodology

Farm Questions
1

Dear All,

This is my first post & thanks to FarmNest for covering such a wide range of agriculture related posts.
I’m basically looking to take some soil samples in my 20 Acre redsoil farm in AP.

Pl advice me the best way to collect.

Regards,
Naren

2

Hi Naren,

Some good references:
mahindrakisanmitra.com/Conte … goryId=129
gunturonline.net/~guntur/htm … ilSampling

From my experience of having got a sample test done with an agriculture dept. lab in AP, a couple of points to bear in mind:

  • Take two samples at each spot and save one sample. It is quite possible the lab might lose the sample and ask you again, and you don’t want to go back to collect samples again.
  • Collect a decent quantity of soil for each sample. While most pics show you a couple of handfuls, the lab guys insist on much more since they sieve the sample and end up with very little to actually test.
  • Have the land ownership details, survey numbers, extent etc. handy. These will be needed to fill in the form that accompanies the samples.
  • Avoid fertilized areas for picking the samples since they will skew the results. How deep should be based on your type of crops.
  • It is better to get some water samples along with the soil. Even if you don’t need them, it is easier to submit them for test than trying to explain to the lab guys why you don’t need a water test, and make a deviation to their laid down process.
  • There is a free and paid test available at Govt. labs (at least in AP). I think things move faster and are probably more accurate if you pay the nominal amount.
  • The list of labs in AP are available online: apagrisnet.gov.in/contact.jsp
  • The test results are also supposed to be available on the website once you enter the farmer name, survey numbers etc. apagrisnet.gov.in/token.jsp
  • You could also try some of the fertilizer companies who do the tests - I think Nagarjuna and Mahindra do them.
  • Some companies are coming up with portable soil test kits - no idea how good they are.

Last and not the least, don’t rely too much on the results and corroborate them with your visual observations.

Regards,
Chandra

3

Thanks Chandra for the vital information.

Regards,
Naren

4

Hi Naren,

I see on another topic you have gotten the test done. Do you want to post your experience?

Thanks.

5

Thanks for the reminder Chandra. Actually, we took the help of a guy from local fertilizer shop (who have experience in taking samples).

Labor dug holes as specified by the guy & he was really helpful as he patiently divided soil into 4 parts, took the diagonal ones and discarded others. Further did the same with the remaining soil. Then, finally, we marked numbers and wrapped the soil in cloth bags.

Next day, we took the samples to the Government soil test department (it was inside market yard in kurnool) and they charged 10/- per sample. Within 24 Hrs, I got a call from them to collect the results. Of course, they didn’t have provision to test micro nutrients(which I have to do later).

They give a results sheet with standard recommendations based on the crop I mentioned.

My results varied all the way from 5.6 to 8.3 PH in the same 20 Acre land. Quite surprised by the results though ;D

Regards,
Naren

6

Interesting. Thanks for posting.

7

Dear Mr.Chandra,
Transchem Agri Ltd, Baroda is supplying soil testing kits.Really is trust worthy. I compared it with instruments when i was studying Gujarat Agricultural University, Navsari -Campus.
The parameters are
soil pH, Organic Carbon, Nitrate --Nitrogen, Ammonical – Nitrogen , Phosphorus, Potash, Calcium,

Magnesium, Sulphur – I don’t any agency is correctly testing soil samples, Labs are there rest God
knows.

You can contact Mr. Mukesh Parmar for More details-09426023703,

Plse test pH of soil with Direct soil Tester, TAKUMURA, JAPAN

Then Compare the reading with pH & Plant nutrient Availability Chart

If You have some experience in Plant Nutrition Management, Visual observations, it is more than

sufficient to check most of the complications.
Thank you
Good Luck

8

Thanks biofarms. I did see the ad somewhere and looked up their website for the product details too. Good to note it works well - it would be good to have the a pictorial detail of testing with the kit on a separate topic.

But it is a large pack of 100 samples and not for individual farmers?

Chandra

P.S.: congrats on 100 posts and becoming a ‘FarmNest Senior’! :slight_smile:

9

Dear Sir,

You are absolutely right. Last year I purchased the kit for cardamom farmers group , (Rs.13,000/-)

of 15 members. For individual farmers it is costly.For cardamom farmers this amount is not a problem.

Why? With New Cardamom Production Technology (NCPT) the current production / per acre is

800- 1000 kg , the present Rate is Rs.600/kg (last year it was Rs.1400- 1600/ kg) -Rs4,80,000/-

Rs.6,00,000/- per acre. If they spent 50% see the profit. Before developing NCPT the average

production was 300 kg -500 kg / acre. Biofarms involvement made a great change in cardamom

cultivation. Another concern is drying of cardamom. Using firewood and diesel in Dryers. Normally

it will take 24- 32 Hours. Biofarms developed a technology to dry cardamom in 12 Hours. This is

a part of energy conservation, Restrict cutting of trees. Coirpith waste is abundant in near by

Districts of Tamilnadu. We have developed Special bricks with coir pith with some ingradients burn

like gas flame for long time. It is in its finishing stage. So my intention is to prevent the cutting of

Trees. Biofarms always want to make a collaboration with farmers ,Environment and Mighty God

That is “Our Success”

Thank you
Good Luck

10

Murali, what is the process to get the soil test done?. Where did you get it done.
regards,
gg

11

Hi GG,

Its very simple, You can get it done at Horticulture Depat, Hulimavi, Bannerughatta road. Total cost Rs 225. But they take a week to give the results.

Regards

Murali

12

Dear Hegade,
Objectives of Soil Testing - The objectives of soil testing area as follows:

  1. To estimate the available nutrient status, reaction (acidic/alkaline) of a soil.
  2. To evaluate the fertility status of soils of a country or a state or a district.

By soil test summaries the fertility status i.e., available nitrogen status or available phosphorous status or available potassium status expressed as HIGH, MEDIUM or LOW. A soil fertility map showing such fertility status can be prepared. The soil fertility map can be used for -
• Delineating areas of nutrient (e.g.,N, P, K) sufficiency or areas of nutrient (e.g.,N, P, K) deficiency,
• Studying soil fertility changing pattern due to crop cultivation over a period of years,
• Determining nutrient (e.g.,N, P, K) requirement for the deficient areas etc.

  1. To prepare a basis for fertilizer recommendation, lime recommendation or gypsum recommendation.
    Soil Testing Programme - A soil testing programme has four phases as follows:
    • Collection of soil samples.
    • Chemical analysis of soil samples.
    • Calibration and interpretation of the results of chemical analysis.
    • Recommendation.

Before giving the soil samples to a soil testing laboratory for chemical analysis, collection and preparation of soil sample should be done with perfection.
Method of Collection of Soil Samples - Collection for field crops
Equipments

  1. Spade
  2. Polythene bucket
  3. 12 inches scale
  4. Ball point pen/Lead pencil
  5. A sheet of thick paper
  6. Polythene sheet (2ft x 2ft)

Procedure

  1. Determine the soil unit (or plot).

  2. Make a traverse over the soil unit (or plot).

  3. Clean the site (with spade) from where soil sample is to be collected.

  4. Insert the spade into soil.

  5. Standing on opposite side, again insert the spade into soil.

  6. A lump of soil is removed.

  7. A pit of vee (V) shape is formed. Its depth should be 0-6" or 0-9" or 0-12". (i.e., depth of tillage).

  8. Take out the soil-slice (like bread-slice) of ½ inch thick from both the exposed surface of the pit from top to bottom. This slice is also termed furrow-slice. To collect the soil-slice spade may be used. Collect the soil samples in a polythene bucket.

  9. Collect furrow-slices from 8-10 or sometimes 20-30 sites. Select the sites at random in a zigzag (or criss-cross) manner. Distribute the sites throughout the entire soil unit (plot). In lieu of spade auger may be used. Do not take the prohibited samples and local problem soils.

  10. Furnish the following information in two sheets of thick paper with the sample. One sheet is folded and kept inside the bag. Another sheet is folded and attached with the bag.
    Informations
    • Name and address of the farmer (or farm owner).
    • Name of the block.
    • Plot number or any other number that identifies the plot (or Soil unit).
    • Soil texture (sandy/clay/loam).
    • Availability of irrigation facilities.
    • Availability of drainage system.
    • Upland/Mediumland/Lowland.
    • Depth of soil sample.
    • Information of the previous crop.

  11. Name and variety of the crop.

  12. Dose of organic manure, if applied.

  13. Dose of fertilizers, if applied.

  14. Yield.
    • Informations of the crop that will be grown.

  15. Name and variety of the crop.

  16. Season (pre Kharif/Kharif/rabi).
    • Problem, if any.
    • Date of sample collection.
    • Signature of the farmer (or farm owner).

Collection for plantation crop
• Dig a well (pit) of 1.8 meter depth. (Depth may vary depending on root-depth).
• Collect the soil-slice of ½ inch thick from the exposed surface of pit at different depths as follows: 0-15, 15-30, 30-60, 60-90, 90-120, 120-150 and 150-180 cm.

Collection for local problem soils - Local problem soils are treated as separate soil units (plots). Hence, separate composite samples are collected from problem soils. The problem soil samples are not mixed with normal soils (i.e., non problem soils). Both surface soil and subsoil samples are collected.

Collection of surface soil sample-Take 10-30 furrow-slices or cores that extend through A1 horizon.
Collection of Subsoil sample Dig a well (i.e. pit) of 1 meter depth. Take soil-slices of ½ inch depth below A1 horizon from different depths as follows: 0-15, 15-30, 30-60, 60-100 cm

WATER TESTING PROCEDURE
In addition to getting soil, collecting water is also important, the following procedures are to be followed to collect water fro testing.
If water is to be collected from bore well, start bore motor and wait for 15 minutes and collect one liter water in plastic bottle and close it properly. Provide completed details of bore well, farmer name address, plot number etc. for correct identification and send it along with soil to following address.

The Office of the District Geology at Distrcit/Karwar along with specified form duly filled and obtain acknowledgment for having submitted the same. Nominal fee has to be paid for testing of soil and water. About 15 day time may be needed to get test the soil and water. Collect contact numbers/lab technician to know the results over phone and to avoid repeated visits to office to know the results. Once it is ready than collect it along with their suggestions for further course of action.

13

Hi ,

At horticulture dept, they have a hand out which says how to take the soil. Since I do not have a scanner, Mr Swamy has put the procedure. Thanks swamy.

One point to swamy, What does EC (ie the electrical conductivity ) indicates. By pH value, we can know if the soil is acidic or alkaline. But what does EC indicate. Can you throw some light.

Others like N, P , K and other metals, it simple, They have a std value and say if it is less or more. For me they recommended to add some gms of NPK as I had indicated that I would like to grow Banana. So their recommendation was for that.

Regards

Murali

14

[quote=Murali]
Hi ,

At horticulture dept, they have a hand out which says how to take the soil. Since I do not have a scanner, Mr Swamy has put the procedure. Thanks swamy.

One point to swamy, What does EC (ie the electrical conductivity ) indicates. By pH value, we can know if the soil is acidic or alkaline. But what does EC indicate. Can you throw some light.

Others like N, P , K and other metals, it simple, They have a std value and say if it is less or more. For me they recommended to add some gms of NPK as I had indicated that I would like to grow Banana. So their recommendation was for that.

Regards

Murali [/quote]

I don’t studied much more on it, however find the link in which details of EC are mentioned.veristech.com/products/ecfaq.aspx#q2

15

Thanks Murali and Swamy, as always you have shared very useful information and procedure.

16

In a nutshell, electrical conductivity is an indicator of the salt content or salinity of the soil. Salt content of soil determines plant roots’ ease of absorbing water from the soil and also impacts the availability of some minerals to plants. Thus EC becomes a factor in plant selection, nutrient recommendations and water management; of course after land selection.

pH and/or EC, together with exchangeable sodium determine if a soil is alkali or sodic too.

17

Hi,

Mine EC is 0.65 and pH is 6.13. Now what does this mean ?? Combined !

Regards

Murali

18

pH indicates the soil is neutral and suitable for a large variety of crops slightly tending to the acidic side. 6 to 7.5 is considered normal with 7 technically being neutral reaction.

What are your units for EC?

19

Hi,

pH is understood. 6th Std chemistry lessons with litmus test paper ;D

EC is complicated. My soils EC is 0.65.

Regards

Murali

20

http://pubs.ext.vt.edu/442/442-508/442-508_pdf.pdf

http://www.agriculturesolutions.com/Resources/The-why-and-how-to-testing-the-Electrical-Conductivity-of-Soils.html

Electrical Conductivity is a very quick, simple and inexpensive method that farmers and home gardeners can use to check the health of their soils. Whereas pH is a good indicator of the balance of available nutrients in your soil, Electrical Conductivity can almost be viewed as the quantity of available nutrients in your soil. (NOTE: Only nutrients that are dissolved in the soil water is “Available” for crops to take in).
What is Electrical Conductivity?
In the soil, the Electrical Conductivity (EC) reading shows the level of ability the soil water has to carry an electrical current. The EC levels of the soil water is a good indication of the amount of nutrients available for your crops to absorb.

Think of it like this, all the major and minor nutrients important for plant growth take the form of either Cations (positively charged ions) or Anions (negatively charged ions). These ions that are dissolved in the soil water carry electrical charge and thus determine the EC level of your soil and how many nutrients are available for your crops to take in. Knowing your soils EC can allow you to make more educated farming decisions.

To support these claims, Researchers at Clemson University documented the correlations between EC and different crop inputs, documenting these at multiple sites over multiple years. They found unmistakable evidence showing that yield data have consistently supported the EC correlations with water, fertilizer, and pesticide use.

Using EC data to develop zones, in six on-farm tests, they overlaid yield maps developed after the crops had been harvested over EC maps developed before the crops were planted and found that the two maps match perfectly.

They also found that where EC levels were high (More available nutrients) less fertilizer is needed but more weed control in places where they had a morning glory problem. For example on sandier soils with low EC ratings, it took only a quarter-pound of active ingredient in the herbicide to get 80 percent control morning glory. On heavier soils with higher EC ratings, it took up to five times that amount to achieve the same level of control.

Other factors also contribute to soil EC variability include the connectivity of the soil water through soil density, soil structure, water potential, precipitation, timing of measurement, soil aggregation, electrolytes in soil water (e.g. salinity, exchangeable ions, soil water content, soil temperature). Also the conductivity of the mineral phase affects the EC reading for example the types and quantity of minerals, degree of isomorphic substitution, and exchangeable ions. Regardless of what these multiple causes of EC variability are, what still remains is that EC measurements are consistently correlated to soil properties that affect crop productivity, including soil texture, Cation Exchange Capacity (CEC), drainage conditions, organic matter level and salinity, so knowing your soils EC level is a great predictor of your plants health.

For example if the soil EC is too high, it can be indicative of excess nitrogen based fertilizer or a high level of exchangeable sodium. Soils with an accumulation of exchangeable sodium are often characterized by poor tilth and low permeability making them unfavorable for plant growth. Soil EC is also related to specific soil properties that affect crop yield, such as topsoil depth, pH, salt concentrations and water-holding capacity. Thus EC is a great tool for explaining what your yields could be and taking action to get better yields.