How to prepare soil fertility maps

2. Food production has to double - without
using more water, more fertilisers and
more land, by 2050, if there is to be
enough to feed the world. The answer is
improved soil fertility.
If not ‘depopulate - Perish’.

3. purpose
To make awareness among the farmers,
researchers, planners and administrators
regarding use of balanced fertilization
according to soil test based
recommendation and integrated nutrient
management for higher and sustainable
crop production.

4. Soil fertility maps are integral components of all
major land evaluation and land use planning
endeavors
–Soil and land resource inventory reports
–Soil survey reports
–Watershed reports
–Fertility assessment studies etc
–Exclusive soil information systems for
consultancy services
_ Enviornmental reports
_ Industrial purposes
(feasibility Assessments)

5. Steps involved in the preparation of soil
fertility maps
Soil sample collection
Soil analysis
Fertility maps

6. Cartography
Photogrammetry
Remote sensing
GIS - Geographic information
system
Global Positioning Systems (GPS)
Cartographic Sciences
Remote sensing
Photogrammetry
GIS - Geographic information
system

7. ….GPS
• A surveying method that uses a set of 24
satellites in geostationary position high above the
Earth.
• Specially designed GPS receivers, when
positioned at a point on Earth, can measure the
distance from that point to three or more orbiting
satellites.
• The coordinates of the point are
determined through the geometric calculations of
triangulation. GPS provides accurate geodetic data
for any point on the Earth.

8. Aerial photographs
Aerial photographs are pictures taken by an
aerial camera fitted into a plane flying
under certain specific conditions of flight.
Single lens vertical photographs, which are
taken in a series of independent
overlapping exposures, are ideal for soil
resource inventory. They have a
convenient size for field survey and map
construction, give excellent detail of
ground features and permit stereoscopic
study.

9. Vertical photos

10. Oblique photos

11. Remote sensing
• A method of viewing and acquiring
information with out any physical contact
through EMR on the Earth's surface from an
airplane, balloon, or satellite (or, for the ocean
floor, from a vessel).
•
•The principal technologies used to collect data
remotely through electromagnetic radiation (EMR), radar,
and sonar in digital form. The data are later processed
into images.

12. Spatial
resolution
Geo eye

13. GIS
A computer-based information system designed to handle geo-
referenced data.
GIS is used to capture, store, update, manipulate, analyze, display
and output a full range of geographical data.
Output can be in many forms: either as tables, graphics, or maps.

14. Selection of sampling locations
• A. Before field: When large areas are of concern
assisted with Imageries, topo sheets
photogrammetry, cadastral maps and interpretation with GIS
Sam
ple

16. am
ple

17. Cadastral sheet (scale 1: 5000)

19. Sampling strategies for fertility
assessment and mapping
no Study area strategy GPS GIS RS
1 Districts, states (wide geogr.
areas covered}
Random sampling yes yes yes
2 Village/ panchayat/
watersheds
Grid/zig zag yes yes yes
3 Fertility assessment of
problem areas
Intensive
sampling
yes yes Not necessary
4 Indls / groups Localised Yes/no Yes/no Not necessary

20. Selection of sampling locations
B. At field : Surveyors judgment
1, when sufficient previous data not available
2, Small areas are mapped
3, when pre-selection is not necessary

21. Steps involved in the preparation of soil
fertility maps
A. Soil sample collection
Systematic and scientific soil sampling

22. Soil sampling procedure- rules
The accuracy and utility of a soil test
result is influenced by the laboratory
analysis but may be influenced even
more by the quality and precision of the
soil sampling.

23. A Good Soil Sample Should Be
Representative of the Area

24. Soil sampling procedure- rules
• Points to be considered:
• Collect 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.

25. • 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.
• Test the soil before crop establishment and
subsequently every three years for perennial
crops and for annual crops it would be good
practice to sample soil annually or at least
biennially

26. Procedure for collection and preparation of
soil samples
• 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.

27. 1 inch / 2.5 cm 6 inches (15 cm)

28. Compartmentalization

29. Soil sampling depth
Sl.No. Crop
Soil sampling
depth (cm)
1 Grasses and grasslands 5
2
Rice, finger millet, groundnut, pearl millet,
small millets etc.(shallow rooted crops)
15
3
Cotton, sugarcane, banana, tapioca,
vegetables etc. (deep rooted crops)
22
4
Perennial crops, plantations and orchard
crops
Three soil samples
at 30, 60 and 90 cm

30. Frequency of sampling
Cropping system frequency
Lawn and ornamental areas Every two to three years
Vegetable gardens/
homesteads
Every one to two years
Plantations Three to five years

31. 2. Soil analysis
A soil test is the analysis of a soil sample to determine
nutrient and contaminated content, composition, and other characteristics such
as the acidity or pH level. A soil test can determine fertility, or the expected
growth potential of the soil which indicates nutrient deficiencies, potential
toxicities from excessive fertility and inhibitions from the presence of non-
essential trace elements..
Steps involved in the preparation of
soil fertility maps

32. Dept of Soil survey & Soil conservation, Kerala

33. Dept of Soil survey & Soil conservation, Kerala

34. Dept of Soil survey & Soil conservation, Kerala

35. Status- Kerala
Dept of Agrl. Kerala Dept of SS and SC
Number of Soil Testing
Laboratories
24. (14 dist labs, 9 mob, 1 soil
& Pl. health care lab)
7 labs across the state
Annual analyzing capacity 2,88,000 soil samples per
annum
1,10,000 soil samples per
annum
Capacity Utilization 65% 75%
Review of functioning by the Chief Soil Chemist and
the Director of Agriculture.
By principal soil chemist &
Director of Dept of SS & SC
Number of Soil Health Cards
issued
during 2011-12 (up to 9/11)
approx. 50,500 soil health
cards were issued.
Duing 2014 approx 15 000 SHC
were issued.
Preparation of soil fertility
map
Fertility maps have been
prepared up to the year, 2012
Fertility maps have been
prepared until the last year
Involvement of State
Agricultural University(s)
recommendations is given in
the soil health cards, based on
the package of practices
standardized by the KAU.
recommendations is given in
the soil health cards, based on
the package of practices
standardized by the KAU

36. Steps involved in the preparation of soil
fertility maps
3. Preparation of fertility maps
Major functions are….
1. Spatial indicators of limitations and potentials of soils
2. Indispensible instruments for formulating, establishing
and maintaining site specific soil fertility programmes
3. A tool in farmer education and awareness campaigns
4. Easy devices for predicting the behavioral pattern of soils

37. GIS
RS data
Photogrammetry GPS data Field check
Soil analytical adata
Soil fertility maps

38. Preparation of fertility maps
Why GIS
• Soil samples were not geo-referenced
• No validation of prepared maps
• Creation of Data base secondary and micronutrients
• STCR Recommendations for any particular field by selecting
through GIS based fertility maps
• Transfer of generated technology to the farmers through govt.
agencies and NGO’S.
• Various analysis and decision supporting tools (Seggregation,
isolation, selection, buffering etc)
• Storage, Modification, interpretation, retrieval

39. Some thematic maps in GIS…..

52. Major soil information
services around the
globe……..

53. United states of America

54. Africa

55. China

57. England

58. Hawaii

60. India

62. Kerala

63. Dept of Soil survey & Soil conservation, Kerala

64. Dept of Soil survey & Soil conservation, Kerala

66. Dept of Soil survey & Soil conservation, Kerala

67. Dept of Soil survey & Soil conservation, Kerala