What Does Contour Plowing Mean?
Contour plowing is the practice of plowing horizontally along the contours of the land. This plowing technique prevents soil erosion in hilly and contoured areas by capturing the water runoff. The contour lines also create a water break that reduces the formation of rills and gullies during heavy rainfall, allowing water to seep into the soil. Contour farming is a sustainable form of agriculture and is mostly done in hilly and sloped areas.
It is also known as contour farming and contour bunding.
Safeopedia Explains Contour Plowing
Contour plowing is one of the oldest methods of conservation plowing. It involves tilling the cropland along its gentle slopes instead of up and down the gradient. This type of tilling is very important in areas prone to heavy rainfall or violent storm, as it prevents the fertile topsoil from being carried downhill by flowing rainwater.
History of Contour Plowing
The first known use of contour plowing is thought to be by the Phoenicians in 1200 to 900 B.C.
During the 1930s, it was one of the main procedures promoted by the United States soil conservation service, now known as the National Resources Conservation Service (NRCS). It was established in 1935 by the US Department of Agriculture in response to the problem of soil erosion and desertification.
By 1938, the introduction of new techniques, including contour plowing, reduced soil loss by 65% despite the drought. A federal program known as The Soil Erosion Service taught farmers to use terracing and contour plowing techniques to preserve soil.
The Contour Plowing Process
Farmers who practice contour plowing start by cutting levels into the hill or contoured areas. This creates a series of steps on the hill on which crops are grown. Small ridges or raised platforms, known as water breaks, are built along the rims of these steps to prevent the water from running downhill. These water breaks help keep the water contained in individual step levels, allowing more time for this water to be absorbed by the ground.
In less steep areas, the land is simply plowed following the contours horizontally.
Benefits of Contour Plowing
The benefits of contour plowing include:
- Maintaining soil fertility, resulting in better yields
- Reducing erosion and preventing habitat destruction
- Minimizing the use of fertilizers
- Increasing the soil's water retention capability
- Enhancing irrigation and water conservation
Drawbacks of Contour Plowing
One of the main limitations of contour plowing is the fact that it leaves pockets of untilled land. Since these pockets are unattended and uncultivated, they can become overrun with weeds. The pesticide used to manage these weeds can kill the surrounding grass, incrasing the possibility of a water runoff. Contour farming also loses its effectiveness with increases in the slop gradient, slop length, and rainfall intensity.