Soil crusting, soil compaction, sub soil hard pan, sand dunes and shallow soils – characteristics and management
1. Soil crusting, soil compaction,
sub soil hard pan, sand dunes
and shallow soils characteristics
and management
SAC 202 Problematic soil and their management (2+0)
K. Maheshwaran,Asst. Prof. (SS&AC)
Sethu Bhaskara Agricultural College &
Research Foundation
2. Deterioration of soil structure where natural soil
aggregates break and disperse
The dispersion followed by rapid drying the soil
solids into crust
Dispersed particles are carried into soil with the
infiltrating water blocking the soil pores
Crust can form all soils textural types excepting
sands
Crust about 5mm thickness
Soil surface crusting
3. Impact on soil properties
Prevent germination of seeds and retards root
growth
Results in poor infiltration and accelerates
surface runoff
Creates poor aeration in the rhizosphere
Affects nodule formation in leguminous crops
Soil surface crusting
4. Surface crusting is prevalent in Trichy, Thanjavur,
Pudukottai, Cuddalore and Sivagangai districts
and mostly in red soil areas
In Tamil Nadu, the area under soil crusting is
around (4.49%TGA)
Soil surface crusting
5. Remedial measures
When the soil is at optimum moisture regime,
ploughing is to be done
Lime or gypsum @ 2 t ha-1 may be uniformly
spread with the surface soil
Farm yard manure or composted coir pith
@ 12.5 t ha-1 may be applied to improve the
physical properties of the soils
Scraping the surface soil by tooth harrow will
be useful
Soil surface crusting
6. Bold grained seeds may be used for sowing on
the crusted soils
More number of seeds/hill may be adopted for
small seeded crops
Sprinkling water at periodical intervals may be
done wherever possible
Resistant crops like cowpea can be grown
Soil surface crusting
7. It is also known as soil structure degradation
Increase of bulk density or decrease in porosity of
soil due to externally or internally applied loads
Compaction can adversely affect nearly all
physical, chemical and biological properties and
functions of soil
Soil compaction
8. Effect of soil compaction
In agriculture, soil compaction is a complex
problem in which soil, crops, weather and
machinery interact
External pressure due to the use of heavy
machinery and inappropriate soil management
can lead to the compaction of subsoil
Creating impermeable layers within the soil that
restrict water and nutrient cycles
Soil compaction
9. Types soil compaction
1. Top soil compaction is considered partly
reversible and its occurrence controllable
2. Subsoil compaction is regarded as the
major problem because it can be permanent,
meaning the pore functions can potentially not
be restored after deterioration.
Soil compaction
10. Management
Practices such as reducing load weight when
possible
Often deep tillage or sub soiling is considered
when compaction problems are severe
Maintain soil fertility, especially with respect to
‘K’ fertilizer
Soil compaction
11. In Red soils due to illuviation of clay to the sub
soil horizon coupled with cementing action of
oxides of Fe,Al and Calcium carbonate
Which increases the soil bulk density to more
than 1.8 Mg m-3
Also develop due to continuous cultivation of
crops using heavy implements up to a certain
depth constantly
It prevents root proliferation and limits the
volume of soil available for uptake of nutrients
resulting in depleted, less fertile surface soil.
Sub soil hardening /hard pan
13. Management
Ploughing the soil with chisel plough
Application of organics to improve the
aggregation
Deep ploughing of the field during summer
season
Cultivating deep rooted crops like tapioca,
cotton so as to encourage natural breaking of
the hard pan.
Raising deep rooted semi perennial crops like
Mulberry, Jasmine etc
Sub soil hardening /hard pan
14. Sand dunes are important coastal features that
provide a habitat for coastal species and
protection for infrastructure
Dunes can be found along beaches in excess of
900 feet tall
Wind-related processes and deposits are also
termed Aeolian processes or deposits
(aeolian from the Latin word Aeolus,
meaning god of the winds
Sand dunes
15. A typical sand dune is created by the transport
of sediment (small loose rock particles) by the
wind and involves the interaction of the wind
and the ground surface
Very small particles are transported in
suspension by the wind and stay in the air for a
relatively long distance
Sand dunes
16. s
Classification of Sand dunes
1. Size and shape of the dunes
2. Environment in which they are occur, coastal,
desert, or polar
3. Growth stages, and degree of internal
complexity
4. Wind direction
Sand dunes
21. The shallow soils are characterized by the
presence of the parent root immediately below
the soil surface at 15-20 cm depth
This restricts the root elongation and spreading
Tamil Nadu which is 1-16 per cent of total
geographical area
Shallow soils are unsuitable for cultivation
because there is a layer that hinders the growth
of plants
The subsoil is very compact so the plant roots
can penetrate with difficulty, making the spread
of plant roots not uniform
Shallow soil
22. Management
The soil should be improved by plowing green
manure crops
Drought-resistant plants with shallow root
systems should be planted
Soil improvement can be done by putting
topsoil without pebbles or gravels
Shallow soil