Water Management

© Roger de la Harpe
The Gariep Dam forms the largest storage reservoir in South Africa, it supplies water to part of the Vaal, Fish and Sundays catchments as well as irrigation along the Orange River.
Seventy percent, of the earth’s surface, is covered by water. Ninety-seven percent of all water on earth is salt water. Less than three percent of all the water is fresh water.

Of the 3% fresh water, only 0.3% is surface water that is easily accessible to us to drink or utilise in the production of the food and commodities we produce to stay alive. The rest is:

69% - Frozen
0.7% - In the atmosphere
30% - Underground

Water is a finite resource. The amount of water that was on earth a million years ago is here now and will not increase. What has to change is how we utilize this valuable and life-giving resource to stay alive. We need to learn not to waste. Of the fresh water that we use:

70% is used for agriculture
20% for industrial purposes and
10% for households and human consumption

To produce food we have to innovate constantly to find new ways to use less and waste less in the production of our food.

To produce one kilogram of beef it takes 15 000 litres or 15 m³ of water.
To produce one kilogram of rice it takes 3 500 litres or 3.5 m³ of water.

We are fortunate that in modern agriculture, innovation has brought us the means to efficiently monitor water content in the soil. This allows for efficient irrigation through new and less wasteful irrigation systems like surface and underground drip irrigation. But still, more than 60% of water used for irrigation in agriculture is wasted through inefficiencies. By effectively measuring the available water in the root zones of different crops, it will help curb these losses.

Irrigation

Irrigation is the manmade supply of water to land for the growing of crops or any other vegetation by means of furrows, channels or pipelines where the rainfall cannot provide the required water for sustained growth and production of crops....more

Methods of Measuring Soil Moisture

It is important to know the moisture condition of the soil so that the grower can irrigate the plant at the correct time to ensure that there is the required available moisture in the soil for the plant’s roots to draw from....more

Water Sources, Storage, Channelling and Pumping

All water reaches the surface of the earth through different kinds of precipitation like snow, rain, hail, sleet or mist. There are two main sources of water we use for agriculture and domestic consumption purposes...more