Cross-ridging Holds Precious Rainwater on the Land

Backgrounder

Do your crops sometimes suffer from lack of water? If so, and if your land is flat or almost flat, what I’m going to tell you now may help you increase your crop yields next season.

Sometimes when it rains, so much water falls in such a short time that it can’t all sink into the ground right away, even if the soil below the surface is dry. Instead, water flows away over the soil surface, always towards the lowest land. Instead of soaking into the ground where your crops can use it, a lot of rainwater is lost.

How can you prevent this?

Well, some farmers in drylands use a special method to help hold that precious rainwater on their land.

First of all, they grow row crops such as maize, sorghum, or sweet potatoes, on ridges. When it rains, water collects in the furrows between the ridges. Now to make sure the water stays where it falls in the furrows and doesn’t flow away, the farmers make little barriers called cross-ridges across each furrow at regular intervals. They build one cross-ridge every 2 or 3 metres along the furrow. The cross-ridges block the furrows off into basins that hold the water in one place.

If you live in a dry area, cross-ridges can help you save water and soil.

First, make the planting ridges for your crops to grow on. If your land is not quite level, you must remember to make your ridges and furrows on the contour across the slope, not up and down. This helps stop water from flowing away, down to lower ground.

The next step is to make the cross-ridges that stop water from moving along in the furrows. You can do this before or at planting time.

Use a hoe or some other tool to make a little wall of soil every two metres along the furrow. Make them at right angles to the main planting ridges. The cross-ridges are like little dams that stop water from moving along in the furrows.

The cross-ridges must never be as high as the main ridges that the crops are growing on. The tops of the cross-ridges should always be at least several centimetres  lower than the main planting ridges. For instance, if the planting ridges are 30 centimetres high, the distance from your elbow to your wrist, then the cross-ridges might be a bit shorter — about 20 centimetres high. That’s to make sure the water doesn’t get too deep and wash over the main ridges where your crop is growing.

What you’ve done is make a series of basins in the field that will collect water every time it rains. The water then sinks slowly into the soil where the roots of your plants can use it. The result is that your crops grow better and give higher yields.

You may find that your ridges and cross-ridges will stay in place for more than one season. This way you’ll have less work to do before planting the next crop.

In areas where there isn’t much rainfall or where rainfall is irregular, this method can be a very useful way to improve crop yields, at least on land that’s flat or nearly flat.