- To intercept the runoff flowing down the slope by an embankment.
- It helps to control runoff velocity.
- The embankment may be closed or open, surplus arrangements are provided whenever necessary.
- Approximate cost for laying contour bund is Rs. 1500/- per ha.
- It can be adopted in light and medium textured soils.
- It can be laid upto 6% slopes.
- It helps to retain moisture in the field.
|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||1.5 : 1||2.18|
Contour bunding construction
Contour bunding along the slope
Contour bunding with Maize cultivation
Contour bunding with Grass
Situations for various bunding options:
|Bunding options||Soil type||Rainfall (mm)||Slope (%)|
|Contour bund||Light soil||>1.5|
|Graded bund||All soils||1.5|
|Bench terraces||Deep soil||>1000||6.0|
|Graded boarder strip||Deep Alfisol and related red soil||>800||>1.5|
In-Situ Moisture Conservation Techniques :
|Soil Type||Rainfall||In-Situ Moisture Conservation Techniques|
|Red soil||Low||Dead furrow at 3-6 m interval|
| ||Medium||Sowing on flat bed and riding later with eventual cultivation|
| ||High||Graded border strips|
|Black soil||Low||Contour cultivation|
| ||Medium||Dead furrows at 3-6 m interval|
| ||High||Graded open furrow (0.2 to 0.3 m3) at 10 m interval across the slope|