What can agriculture do about water use?

Some parts of northern South Africa are emerging from a two season-long drought; the Vaal Dam has reached capacity, and other northern dams are showing good water volumes. The Western Cape, however continues to struggle with dire water shortages. In February 2017, Cape Town mayor Patricia de Lille was reported to be considering declaring the region an emergency disaster area, as the average dam level in the province dropped below 33%.

Most of South Africa’s water resources are used for agriculture. 59% of water is used for irrigation, while 25.1% is used by urban areas — for homes with gardens, 46% of water is used on gardening. Many predict that South Africa will face more and more severe droughts — climate instability is expected to increase in coming years. South Africa is already a water-scarce country — classified as a semi-arid, water stressed country, with an average rainfall of about 450mm, which is well below the world average of about 860mm per year. Making matters worse is that 43% of the rain falls on only 13% of the land.

With the value of water becoming ever clearer, what should South African agriculture do to reduce their water intake?

The right equipment makes water less tight

Not all agricultural equipment is equal. Many kinds of equipment are designed overseas, for soil types and environments that are vastly different to what is present in South Africa. As a result of using inappropriate equipment, farmers can encounter unwelcome and unexpected results from use — from soil erosion, to too little water being absorbed by over-compacted soil.

South African engineers have tackled this problem with aplomb. Tillage equipment produced by South African agricultural engineering firm Radium, for instance, was designed after farmers realised that their old tillage equipment was causing soil compacting tunnel layers to form beneath the soil. This was particularly prevalent in sandy soils, which is a common South African soil type. The firm’s solution, called the Dual Tine Ripper, saw marked improvements in water absorption, deeper roots, and used 40% less energy than prior designs. Better equipment can mean less water use.

Other options for agriculture

Mike Muller, Visiting Adjunct Professor at the University of the Witwatersrand, argues in an article for the Conversation, that there are two major strategies that the agricultural sector can pursue in order to cut down on water usage. Professor Muller argues that agriculture’s water use will increasingly come under pressure from urban demands — and that ultimately urban interests will win out due to greater numbers.

Muller’s first strategy is for farmers, through agricultural unions, to get more involved with water management bodies. Water waste through poorly maintained infrastructure is a huge problem, and by having open lines of communication between farmers and water managers can lead to wastage issues being resolved in good time.

Muller’s second strategy is more radical. He argues that South Africa should scale back its agricultural industry, and instead direct its efforts to growing staple crops in neighbouring countries, like Zambia, Mozambique, Zimbabwe and Angola, which receive far more rain. This “Into Africa” strategy has been gaining some momentum, with South African farming expertise in high demand on the continent.

Whatever strategy wins out, it’s clear that South Africa’s water problems are only going to worsen if things continue as they have been.