afforestation techniques for degraded lands

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Vikas Kumar [email protected]

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Page 1: Afforestation techniques for degraded lands

Vikas Kumar

[email protected]

Page 2: Afforestation techniques for degraded lands

Deterioration in the quality of land, top soil, vegetation and

water resources caused by exclusive or inappropriate

exploitation.

The term ‘degradation’ refers to irreversible decline in the

‘biological potential’ of the land.

Page 3: Afforestation techniques for degraded lands

Biophysical factors: land use and management, deforestation

and tillage methods.

Socio-economic factors: land tenure, marketing, institutional

support, income and human health.

Political factors: political stability forces that influence the

effectiveness of processes and factors of land degradation.

Page 4: Afforestation techniques for degraded lands

Wind erosion

Water erosion

Physical degradation

Chemical degradation

Page 5: Afforestation techniques for degraded lands

Climatic conditions

Terrain and landscape position

Vegetation

Edaphic factor

Management practices

Page 6: Afforestation techniques for degraded lands

Use of remotes sensing data

Direct observation and measurements

Page 7: Afforestation techniques for degraded lands
Page 8: Afforestation techniques for degraded lands
Page 9: Afforestation techniques for degraded lands
Page 10: Afforestation techniques for degraded lands

Ravine means “network of gullies”.

Causes of ravine formation

Destruction of forests

Unplanned cultivation

Destructive grazing

Severe water erosion

Page 11: Afforestation techniques for degraded lands
Page 12: Afforestation techniques for degraded lands

Integrated approach of soil conservation and vegetative

measures and restricted cutting of vegetation .

Protected these areas from biotic agencies

Soil conservation measure like

In moderate slopes ,contour trenching or bunding are done .

Steep gullies are stabilized by construction of gully plugging

and check dams.

Page 13: Afforestation techniques for degraded lands

.

Grasses :Panicum antidotale,Cenchrus ciliaris,which helps in

stabilisation of contour bunds.

Trees :Accia catechu and Dalbergia sissoo ,acacia nilotica

,prosopis julifera are selected for planting

Page 14: Afforestation techniques for degraded lands

Moving wind dislodges the soil particles and transported to

considerable long distances particularly in absence of

vegetation cover leads to formation of sand dunes.

These soils are having low organic matter, poor structure, low

clay content ,low microbial activity and moisture.

Page 15: Afforestation techniques for degraded lands

Sand dune fixation and stabilization through micro wind

breaks

Creation of wind breaks and shelter belts

Trees: prosopis julifera,acacia albida,azdirachta indica.etc

Shrubs and grasses: callygnum ppolygonoides,cenchrus ciliaris

pannicum antidotal,etc.

Page 16: Afforestation techniques for degraded lands

Hills have become barren and denuded because of large scale

and unrestricted felling's in forest areas

soil is shallow,stony,poor moisture content and low in nutrient

status

Run-off is excessive and erosion is severe

Grazing and illicit incidence are very high

Page 17: Afforestation techniques for degraded lands

Staggered contour trenching is practiced to help the soil and

water conservation .

Where slopes are very steep ,shallow “thallies” are prepared

for direct sowing.

Area fenced and closed for grazing.

In steeper slopes pits of size 30-40cm are dug and planting is

done.

Very hard trees is chosen for planting like Acacia ,eucalyptus

prosopis ,etc for tropical region and pinus roxburgii,cedrus

deodara,etc for temperate regions

Page 18: Afforestation techniques for degraded lands

Mining activities that extract ore or raw material from earth both

from surface as well as subsurface.

Open cast mining

Surface mining

Page 19: Afforestation techniques for degraded lands

Covering toxic or infertile material with soil or waste of better

quality.

Use of lime or gypsum to neutralize the acidic or alkaline soils

Leaching of salts by means of rainwater .fertilizing with

organic and inorganic fertilizers

Stabilizing of surface of very fine particles by mulching

Pits of size 60cm3 are usually dug up at spacing of 2m.

The pit should be filled with the fertile soil

Planting activities are carried out.

Page 20: Afforestation techniques for degraded lands

Areas exceeding optimum moisture content ,pore space become

partly filled ,aeration become difficult and less favourable for tree

growth these conditions are called water logged areas.

Afforestation of such lands needs special treatment which

includes

Drainage of excessive water

Reduction of salinity

Planting with suitable trees.

Page 21: Afforestation techniques for degraded lands

Improving drainage facilities by deepening drains

Removing of salinity by constructing series of mounds and

ditches

Tall and high transpiration rate of seedlings should be prefer

for planting

Suitable tree species: Casuarina equisetifoia

Syzyzium cumni

Terminalia arjuna

Eucalptus sps,etc

Page 22: Afforestation techniques for degraded lands

Skeletal soils

These soils are very shallow ,coarse,poor,eroded and

degraded.

These occurs both in low and high rainfall areas

Afforestation techniques

Contour trenches are or staggered trenches are made in order

to conserve soil moisture.

In rocky areas ,where soil particles are absent ,digging of deep

pits and filling them with soil brought from outside and

planting is done .

Page 23: Afforestation techniques for degraded lands

High rainfall areas:

cupressus torbolusa and C.arizonica

Pinus ponderosa ,etc

Low rainfall areas:

Eucalyptus terticornis

Acacia sps

Prosopis sps.,etc

Page 24: Afforestation techniques for degraded lands

Total precipitation usually less than 50mm.

Soils are neutral or alkaline in nature

Wind erosion is common

Short growing season

Page 25: Afforestation techniques for degraded lands

Trench cum pit type:

gentle slope areas

Digging of staggered contour trenches 4.3m long,60cm wide

at bottom and 1m wide at top at a spacing of 10m.

In between trenches pits of 60 cm and 1m deep are dug at 2m

spacing.

Trenches and pits are filled with 50;50 mixture of dug up soil

and fine silt

Page 26: Afforestation techniques for degraded lands

Trench cum drianage type

Low lying areas such as river banks and marshy lands.

To leach out salts from the root zone of plants, planting is

done in crow bar holes of 45 to 50 cm deep .

Choice of species:

Salix alba

S.fragilis

Populus alba

P.ciliata,etc

Page 27: Afforestation techniques for degraded lands

Saline soils

pH<8.5

exchangeable Na <15%

Dominance of neutral salts such as chlorides and sulphates.

Alkaline soils

pH>8.5

Exchangeable Na>15%

Carbonate of sodium are dominant soluble salts

Page 28: Afforestation techniques for degraded lands
Page 29: Afforestation techniques for degraded lands
Page 30: Afforestation techniques for degraded lands

Production of loose soil by breaking the clay pan or kankar

pan

Replacement of exchangeable sodium by addition of

amendments

Maintenance of soil fertility

Trench ridge method is used rather than the pit method of

planting

Digging of pits upto 90 to120cm are also followed for planting

purposes.

Page 31: Afforestation techniques for degraded lands

The species should be tolerant to salt and alkalinity.

Pongamia pinnata

Terminalia arjuna

Prosopis julifera

Albizzia amara,etc

Page 32: Afforestation techniques for degraded lands
Page 33: Afforestation techniques for degraded lands
Page 34: Afforestation techniques for degraded lands

Ridge-trench method

Sub-surface planting in auger holes of 30-45 cm deep.

Planting in deep trenches or furrows.

Page 35: Afforestation techniques for degraded lands

Eucalptus hybrid

Madhuca latifolia

Xylia xylocarpa

Pterocarpus santalinus

Tectona grandis

Pterocarpus marsupium

Page 36: Afforestation techniques for degraded lands

Land degradation will remain an important global issue for the

21st century because of its adverse impact on productivity,

environment, and its effect on food security and the quality of

life.

So there is an urgent need to address these issues through a

multi-disciplinary approach, but the most urgent need is to

develop an objective, quantifiable, and precise concept based

on scientific principles to solve these land degradation

problems.

Page 37: Afforestation techniques for degraded lands

Eswaran.H., Lal .L and Reich.P.F . An overview of land

degradation.

Degraded and Wastelands of India ICAR publications

Page 38: Afforestation techniques for degraded lands