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

12. 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

17. 1. Transverse
2. Oblique
3. Longitudinal
4. Barchan
5. Star
6. Parabolic
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

23. Shallow soil

24. Shallow soil