In-Situ Moisture Conservation Techniques
Micro catchments:
1. Functions
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To conserve insitu moisture and reduce soil loss
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Circular basin of one meter dia for level lands depending upon infiltration and rainfall
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‘ V’ ditches of size 5m x 5m with trees planted centre and height according to the rainfall and slope of slopy lands
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Saucer basins / semi circular bunds with 2m diameter to a height of 15-20cm across the slope
Broad beds and furrows:
1. |
Function |
: |
To control erosion and to conserve soil moisture in the soil during rainy days |
2. |
General information |
: |
The broad bed and furrow system is laid within the field boundaries. The land levels taken and it is laid using either animal drawn or tractor drawn ridgers. |
3. |
Cost |
: |
Approximate cost for laying beds and furrows is Rs. 1000/- per ha. |
4. |
Salient features |
: |
|
Conserves soil moisture in dryland. |
|
Controls sol erosion. |
|
Acts as a drainage channel during heavy rainy days. |
|
Contour bund:
1. |
Function |
: |
To intercept the runoff flowing down the slope by an embankment. |
2. |
General information |
: |
It helps to control runoff velocity. The embankment may be closed or open, surplus arrangements are provided whenever necessary. |
3. |
Cost |
: |
Approximate cost for laying contour bund is Rs. 1500/- per ha. |
4. |
Salient features |
: |
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It can be adopted in light and medium textured soils. |
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It can be laid upto 6% slopes. |
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It helps to retain moisture in the field. |
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Specification for Bund Cross Section
Depth of soil
m |
Base width m |
Top width m |
Height m |
Side slope m |
Area cross section sq.m |
Shallow soils
(7.5 – 22.5 cm) |
2.67 |
0.38 |
0.75 |
1.5 : 1 |
1.14 |
Medium soil
(22.5 – 45 cm) |
3.12 |
0.60 |
0.85 |
1.5 : 1 |
1.56 |
Medium deep soils |
4.25 |
0.60 |
0.90 |
2 : 1 |
2.18 |
Situations for various bunding options:
Bunding options |
Soil type |
Rainfall (mm) |
Slope (%) |
Contour bund |
Light soil |
<600 |
>1.5 |
Graded bund |
All soils |
>600 |
1.5 |
Bench terraces |
Deep soil |
>1000 |
6.0 |
Graded boarder strip |
Deep alfisol and related red soil |
>800 |
>1.5 |
|
