SPATIAL VARIABILITY OF SOIL ORGANIC CARBON IN DIFFERENT LAND USE SYSTEM USING GIS AND REMOTE SENSING BY SHARAT KOTHARI

1. UNIVERSITY OF AGRICULTURAL SCIENCES
BENGALURU
College of Agriculture
Hassan
SOIL SCIENCE & AGRICULTURAL CHEMISTRY
NRM401

3. Spatial variability of soil organic carbon
under different land use system using GIS &
Remote sensing

4. Spatial Variation
• Spatial variation occurs when
a quantity that is measured at
different spatial location
exhibits value that differ
across the location.
• Soil is a heterogenous entity
that vary with both space and
time
• Soil organic matter which is
known as life of soil is also
subjected to spatial variation.

5. Factors responsible for variation in SOC
1. Climate
• Tropical vs temperate
• Temperature
• Rainfall
• Vegetation
• Microorganisms

6. 2.Difference among soil orders
SOIL ORDER GLOBAL
AREA(1000 KM2)
GLOBAL ORGANIC
CARBON IN UPPER
100CM.
1.ENTISOL 21137 90
2.INCEPTISOL 12863 190
3.HISTOSOL 1526 179
4.ANDISOL 912 20
5.GELISOL 11260 316
6.VERTISOL 3160 42
7.ARIDISOL 15699 59
8.MOLLISOL 9005 121
9.SPODOSOL 3353 64
10.ALFISOL 12620 158
11.ULTISOL 11052 137
12.OXISOL 9810 126
MISC..LAND 18398 21
TOTAL 130795 1526

7. 3.Effects of texture and drainage
• Causes variation in SOC within local landscape
• As clay content of soil increases soil organic carbon
accumulation increases
• Generally Soil organic carbon content varies as
CLAYEY SOIL>LOAMY SOIL>SANDY SOIL
Good drainage leads to good aeration condition and rapid
decomposition of SOM.

8. 4.Agricultural management system
ExcessiveTillage operations leads to rapid oxidation and
loss of SOC.
So land where Minimum tillage or no tillage ,Organic
farming system are practised generally have high SOC
content.
Shifting cultivation leads to rapid loss of SOC.
When residues are Incorporated SOC content increases.
Legume based cropping system are beneficial to Increase
SOC content.

9. Variation in SOC in different land use systems
Pasture and grass land. Forest land
>5% SOC 2.5- 4% SOC

10. Wetland /Swampy land
10-29%SOC

11. Mountain lands and waste land
Top –Less Soc
Bottom –High Soc
0.1-0.7%Soc
Stable

12. Agricultural land use system
1.Legume based cropping system
Legumes produce more dry matter per unit area and increases microbial activity
Hence organic carbon content increases over the time.

13. 2.Cereal based cropping system
Generally cereals are exhaustive crops and dry matter produced are not returned to the soil so SOM content decreases over the period

14. 3.Cereal legume intercropping & rotation
Here exhaustiveness of cereal is neutralised by legume and this system is sustainable with respect to SOC

15. 4.Plantation crop based systems
SOC content increases over the years with respect to plantation crops
Generally SOC content higher than other systems.

16. Variation in different plantation crops

17. 5.Organic farming system
This system aims to increase and maintain SOC
in cropland .
S0C content ranges from 2-3.5%
Sustainable with respect to SOC.

18. Using Remote sensing and GIS for estimation of SOC
Variability
• Laboratory methods used are
laborious and need more time
• It is impossible to determine SOC in
Unsampled area by conventional
methods hence these new methods
are promising

19. Satellites &sensors used
IRS P6
LANDSAT 7 ETM
SENSORS USED
OLI-Operational land imager
TIRS-Thermal infra red sensors
ETM-Enhanced thermal mapper

20. WORKING
It uses infrared light.
SOM alter the manner in which soil surface
reflects the IR radiation.
The reflected energy scanned over near IR
radiation spectra.
At these wavelength SOM produce special
absorption pattern related to particular
vibration caused by stretching and bending of
molecular bonds
This is known as hyperspectral remote
sensing.

22. Geostatistical analysis of the data

23. GEOSTATISTICAL MODELS
1.Ordinary kriging(OK)
2.Cokriging
3.Inverse distance weighing(IDW)
4.Radius basis function.
5.Emperical bayes kriging
Uses ERDAS IMAGINE SOFTWARE V9.0

24. Verifying the map
Sampling using GPS
Analysis in the lab and confirmation

28. Importance of knowledge of spatial data
1. Indicator of soil quality
2. Important for ecological modelling
3. Environmental prediction
4. Precision agriculture
5. Natural resource management
6. Soil fertility evaluation
7. Environmental management policies

29. REFERENCE
• Journal of saudi society of agricultural sciences- Gourishankar Bhunia,Pravat
Kumar,Ramakrishna maiti 2016. Comparision of GIS based interpolation methods for
spatial distribution of soil organic carbon ,
• Agarwal ,O.P.Rao,Chauhan,Khandelwal 1995 .Geostatistical analysis of soil salinity
improvement with subsurface drainage system.
• Saha,D.Kukal,S.S.Bava 2012.Soil organic carbon stock and fraction in relation to land
use and soil depth in the degraded shivalik hills of lower Himalayas.
• Books referred-Nature and properties of soil –N . C. Brady
Soil fertility and fertilizers-Tisdale & Nelson

30. THANK YOU
SUBMITTED BY-
Sharat Kothari (ALH 5066)
4th BSc . Agriculture