Gariep Dam in the Free State, South Africa.
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.
Collecting water or ‘rainwater harvesting’ from roofs for household and garden use is widely practised across South Africa - in rural areas and increasing more in cities....more
Poor soil conservation practices and deforestation lead to massive soil erosion and land degradation. Methods of rainwater harvesting include diverting, collecting and storing runoff water....more
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
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
There are three systems for harvesting rainwater. Micro-catchment is the collection of rainwater from the runoff on the farm, while roof-top micro-catchment, is the collection of rainwater from the roofs of buildings....more
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
Rainwater harvesting is the channelling and storing of rainwater from the earth or the roofs of buildings via pipes or gutters to a water storage tank....more