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SOIL
TESTING

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Presently soil testing facilities are
available for farmers, on subsidised rate in the soil
testing Labs operated by Department of Agriculture, M.P.
Soil Testing Charges
a- Macro element(Nitrogen,Sulpher,Potash, Ph & Electrical
conductivity) 12 Rs.5/ sample for General farmerRs.3/
sample for SC/ST farmer
b- Micro element(Based on the capacity of cathodlamp in
the lab 12 Rs.40/ sample for General farmersRs.30/ sample
for SC/ST farmers
Following are the soil testing laboratries where major
soil neutrients can be analysed.
1 . Pawarkheda
2 . Bhopal
3 .Sehore
4 .Ujjain + Ujjain (Mobile)
5 .Mandsaur
6 .Dhar + Dhar (Mobile)
7 .Khargone
8 .Khandwa
9 .Balaghat
10 .Chhindwara
11 .Narsingpur
12 .Sagar
13 .Nawgaon + Nawgaon (Mobile)
14 .Rewa + Rewa (Mobile)
15 .Morena
16 .Bhind
Soil Survey Laboratories which having Soil Testing Facilities
:-
S.No. Soil Survey Laboratory
1 Jabalpur
2 Indore
3 Gwalior
4 Sagar
5 Nawgaon (Chatarpur)
6 Rewa
7 Khandwa

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Soil
Testing
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Why Soil testing is necessary :-
1. Soil fertility is assessed by soil testing.
2. High dose of Chemical fertilizers are being used by
the farmers to increase production of various hybrid varities
of crops.
3. If farmers can use the balanced doze of fertilizer
for crop production then unnecessary financial loss can
be avoided.
4. Soil testing can be useful to maintain the soil health.
To know the soil fertility, periodically soil testing
is necessary.
5. Ph status (Acidic or base) of the Ag. field can be
known by soil testing. Appropriate use of fertilizer for
crop production can be recommended on the basis of Ph
value of soil.
6. Soil testing categorize the soil in to various categories
such as Saline, Alkaline or Mineral soils. The farmers
can be advised to convert such soils in to normal soils.
Before describing the objectives of soil testing, it
is necessary to understand what is soil testing ?
"Soil testing is a Chemical process by vertue of
which requirement of neutrients for plant can be analysed
so as to maintain the soil fertility.
Objective of Soil Testing :-
1. To promote organic fertilizer & insecticides on
the basis of balanced use of fertilizer.
2. To prepare fertility map of specific area such as Block
or Microwatershed etc based on soil testing report. This
will help in advocating appropriate cropping system in
the said area.
3. To make certain specific cropping system more economically
viable with respect to crop production.
4. To stop indiscriminate use of fertilizer.
5. Appropriate fertilizer dozes can be recommended on
the basis of soil testing such as – In Normal soil
(Ph- 6 to 6.5) all Nitrogeneous fertilizer, Super phasphate,
Amonium phasphate etc. can be used. Similarly in the soil
having less than 6.00 Ph value, Calcium amonium nitrate,
Sodium nitrate, phasphetic fertilizer. Super phasphate,
Murate of potash etc can be applied. In the soils having
more than 8.5 Ph value, Urea , Ammonium sulphate, Amonium
cloride, Super phasphate , Amonium phasphate, Murate of
potash etc are recommended. The water logges soils can
be applied Urea, Amoninium sulphate, Super phasphate ,
Amonium phasphate , Amonium chloride etc.
6. To identify the quantity of organic carbon in the soil
is one of the major objective of soil testing , because
growth of crop & availability of neutrients are based
on organic carbon. The ratio of organic carbon & nitrogen
is 10-12:1. The propogation of useful bactiria also depends
on it.
7. Soil testing recommends the ingradiant required to
reclame the acidic soil or saline soils etc.
8. The deffeciancy of micro element like Znic, Copper,
Boron, Molebdinum, Iron, Cobalt, Silicon, Mangnese &
Clorine etc also advarsely affect the crop condition &
ultimately the production.

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Soil
Sample Process:
The testing in the laboratory requiresonly
a few grams of the soil sample, yet the sample sent
to the laboratory must be a true representative
of the field in question. In a homogenous field,
soil samples from plough layer (0-15cm) should be
selected randomly in a zig-zag manner. The samples
should not be collected from near the bunds, water
channels, field paths and heaps of crop straw, stubbles,
manure, etc.
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The sample collected from the selected
sites should be composite and mixed thoroughly in a container.
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From this lot a representative sample,
about 500 gm should be taken out and air-dried under shade.
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The air-dried sample should be
transferred into a clean cloth bag bearing a slip with a mention of complete
address, field number, cropping sequence being followed, source of irrigation
(tubewell/canal), soil type (coarse textured fine textured, alkali or
waterlogged), fertilizer/manure schedule followed in the preceding crops and
any other specific observation about the soil and/or the crops grown therein.
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Then the sample should be taken to the
laboratory where facilities for testing soils for micronutrients are available.

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Prescribed
Area for taking Soil Samples:
| Land Use |
Area(in Hect.) |
| Pastures, permanent grass |
5-10 |
Cultivated Crops:
-level terrain
-eroded terrain
-irrigated terrain |
2 - 5
1 - 2
0.5 - 1 |
| Orchards, vineyards, forests |
0.5 - 2 |
| Vegetable gardens, irrigated |
0.5 - 1 |
| Greenhouse, nursery, lawns |
0.1 - .2 |
When to Take Samples
At least one month before planting
time.As a rule 'if soil is too wet to plow, it is
too wet to sample'.Try collecting samples at the
same time every year
Frequency of Soil Sampling
Soils from coastal plains, sandy,
light textured soils - sample once after every 2-3
crops Silty, clay loams and mountain soils- sample
once every four cropping years.

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Easy
to clean, rust resistant, strong and easy to
use
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Take
small, equal volume of soil from each sub-sampling
site to obtain composite size.
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Adaptable
to dry sandy soils as well as moist sticky soil
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Provide
uniform cores or slices of equal volume at all
spots within the composite area
Soil
tube, screw auger, spade, shovel are some of the
sampling tools most commonly-used.
If spade or shovel is used, it is advisable to make
a 'V' shaped cut into soil at required depth and
few cm thick vertical slice is removed to the same
depth from both sides.Before sample collection,
organic debris, rocks and trash must be removed
from the surface of sampling area.

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Prescribed
Depths of soil Sampling
| Crop/Soil |
Sampling
Depth (Cm) |
| Arable
crops |
15 |
| Orchards |
20-30 |
| Lawns
and Turf |
10 |
| Gardens |
15 |
| Deep
rooted crops / Problem soils |
30/60 |
| Regular
tillage |
20 |
| Minimum
tillage |
15 |
| Zero
tillage |
15-20 |
| Continuous
ridge |
10/15 |
| Pastures
and Forages |
8-10 |

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Directions
while Soil Sampling and Preparation
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Soil samples should not be collected from recently
fertilised areas, bunds, low lying corners,
spots near trees, fences, channels, compost
pits, etc.
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Samples
should be drawn between rows in line sown cropping
areas.
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Sampling
should be done separately for areas represented
by different crops, problem spots, etc.
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Once
the soil is collected, the bulk soil is mixed
thoroughly and desired quantity of soil sample
is obtained by 'quartering method'.
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Soil
samples should not be placed in fertiliser bags,
and in porous cloth.
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Wet
samples should be dried in shade before sending
them to the laboratory.
Soil
Test Interpretation for Fertilizer Recommendations
After
collection and analysis of soil samples, it is the
responsibility of the analyst/scientist to interpret
the results and properly give the fertiliser recommendations
to farmers. Many people have an impression that
soil testing is a simple procedure to determine
the plant nutrients that are deficient and recommend
those nutrients in fertiliser form so that harvests
are assured. Nevertheless, soil testing is much
more than determining nutrient availability.
Various
approaches used for fertiliser recommendations
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Generalised fertiliser recommendations
(or) Agronomic fertiliser recommendations.
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Fertiliser recommendations based on soil
critical levels
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Fertiliser recommendations adjusted based
on soil fertility categories
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Fertiliser recommendations for maximum
yield
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Fertiliser recommendations for certain
percentage of maximum yield
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Fertiliser recommendations for specific
yield targets
Soil Test Calliberation
Incorporation of generated data
through intensive research and establishing a significant
relationship between.
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Soil
test values and the uptake of applied plant
nutrients by a particular crop
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Calibration
between soil tests values and crop yield responses
to rates of plant nutrients applied through
fertilisers in the field
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Changes
in soil test values that occur when known quantities
of fertilisers are applied to the soil

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Ratings
of soil test parameters
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| Nutrients |
High |
Medium |
Low |
| Organic carbon (%) as
a measure of available N
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<0.5 |
0.5 - 0.75 |
>0.75 |
| Available N by
alkaline permanganate method (kg/ha) |
< 280 |
280-560 |
>560 |
| Available P by Olsen's
method (kg/ha) |
<10 |
10-24.6 |
>24.6 |
| Available K by
ammonium acetate method (kg/ha) |
<108 |
108-280 |
>280 |
Quadratic Response Equation
Y = A + b1SN + b2SN2 + b3 SP +
b4SP2 + b5SK + B6SK2 + b7FN + b8FN2 + b9FP + b10FP2
+ b11FK + b12FK2 + b13FNSN + b14FPSP + b15FKSK
Where,
Y = Crop Yield (kg/ha)
A = Intercept
bi = Regression coefficients (kg/ha)
SN, SP, SK = Soil available N, P and K (kg/ha)
respectively
FN, FP, FK = Fertiliser N, P and K (kg/ha) respectively
Mitcherlich-Bray equation
| Availble
Nutrient |
High |
Low |
Medium |
| N(Nitrogen) |
63.10% |
25.57% |
11.33% |
| P(Phosphorous) |
42.33% |
37.66% |
20.01% |
| K(Potassium) |
12.93% |
36.65% |
50.42% |
Log (A-Y) = Log A - c1b - cx
Where,
A = theoretical maximum yield
b = native soil nutrient
Y = yield obtained
x = added fertiliser
c1 = efficiency factor for soil nutrient
c = efficiency factor for added nutrien
Target Yield Equation
FD = NR/CF *100*T -CS/CF*STV
Where,
FD = Fertiliser N or P2O5 or K2O (kg/ha)
NR = Nutrient requirement of N or P2O5 or K2O (kg/t)
CF = Contribution from fertiliser N or P2O5 or K2O
(%)
CS = Contribution from soil N or P2O5 or K2O (%)
STV = Soil test value of N or P X 2.29 or K X 1.21
(kg/ha)
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Soil
Survey is one of the important tools to assess the nutrient
requirement for a crop/cropping sequence. This helps to
economize on cost of fertilizers and also in increasing
fertilizers use efficiency. There are 514 soil-testing
aboratories in India with a capacity of about 6.5 million
samples per annum.In order to provide soil-testing facilities
to all 106 million farms holding in a reasonable period
of time, the existing analyzing capacity of the soil testing
program needs to be augmented almost 15-20 times.
Madhya
Pradesh is having presently 22 Soil Testing Labs and Soil
Surveyors. The main objective of Soil Health Centres is
to maintain the soil health by analysing nutrient status
of the soils and to give suggestions on the quantities
of major nutrients like nitrogen, phosphorus, potassium
to be applied to the soils. Micro Nutrient analysis is
also important to know the status of Manganese, Boron,
Zinc, Iron etc., present in the soil and accordingly suggest
supplimental application for better plant growth.
Steps
required to strengthen soil-survey are improve the capacity
utilization of existing soil-testing labs, adding facilities
of micro-nutrients at selected labs, introducing tissue
testing particularly for sugarcane, horticulture and plantation
crops and encouraging private sector participation for
adding new capacity. Based on the analysis of 4.84 million
soil samples, the fertility status of the soils with regard
to the content of available nitrogen, available phosphorus
and available potassium have been worked out which indicate
the following status on all India basis:-
Available
N P K Status of soils
| Availble
Nutrient |
High |
Low |
Medium |
| N(Nitrogen) |
63.10% |
25.57% |
11.33% |
| P(Phosphorous) |
42.33% |
37.66% |
20.01% |
| K(Potassium) |
12.93% |
36.65% |
50.42% |
Soil
testing till today has been used mainly to formulate precise
recommendations for the major nutrients i.e. nitrogen,
phosphorus fertilization of crops in different soils and
to recommend appropriate doses of amendments for salt-affected
and acidic soils. Micronutrients, comprising zinc, copper,
iron manganese, boron and chlorine, though required by
plants in much smaller amounts, yet are as essential for
them as the major nutrients. Despite that, little attention
has been paid to employ the soil testing for assessing
the micronutrient status of soils and determining soils
requirement for micronutrient fertilizers for growing
crops.
With
an objective to extend the advisory service to the farmers
of the state regarding the nutrient problems of soils
and crops and suggest appropriate remedial measures for
efficient correction of the same, Jawahar Lal Nehru Agriculture
University and the Department of Agriculture have established
soil testing laboratories for nutrient. Farmers are advised
to make the best use of this service rendered by these
laboratories. Soil test can be performed for the soil
of farmer by just paying Rs 50.
(i)
Classification of soils.
(ii) Evaluate and monitor soil fertility.
(iii) Identify salinity, alkalinity, acidity, etc., problems.
(iv) Assess the relative nutrient supplying power of soil.
(v) Predict profitable responsiveness of soil to added
fertilisers, lime, gypsum and other amendments for optimum
and economical crop production.
Success
or failure of soil testing programmes largely depends
on rapidity of providing correct information to farmers,
ability of the programme to provide service to a large
group of farmers in a particular area, proper calibration
and interpretation of results and recommendations that
when followed are profitable for the farmer. Then only
will this service be effectively utilized to improve local
agricultural production Time and quality consciousness
in the service is a real challenge for the analysts in
the new millennium. This compels labs to adopt rapid,
reliable, time saving procedures and methods to meet future
requirements. The farmer's confidence in the programme
can be established only by demonstrating that it actually
provides a means of improving his profit.

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