Water in Agriculture: Adapting to a Changing Climate
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Some parts of the world are overflowing with water, while others never get enough. We find out how farmers in both realities are adapting to keep feeding the global population.
Water covers more than 70% of the Earth’s surface – but it isn’t distributed equally. In many countries around the world, mankind is faced with either “too much” or “too little” water – and a decreasing chance of it ever being “just right.”
Driven predominantly by the melting ice in Greenland and Antarctica, global sea levels are rising at an alarming and accelerating rate, which, according to a 2018 study based on data from NASA and European satellites works out to an additional 26 inches of water by 2100.
In agriculture, access to the right amount of fresh water is directly linked to a farm’s productivity and, ultimately, the farmer’s profitability. And it isn’t just a problem when the levels dip too low; in the Netherlands, the situation swings the other way, with rising sea levels rendering large portions of the country vulnerable to flooding, or even submersion.
Almost a third of the country – including 90% of the bustling city of Rotterdam – lies below sea level. Its citizens are no strangers to the war against water, having battled to keep the sea at bay for many centuries. Today, no nation is better known for its powerful and pervasive water-management strategy, characterized by a network of dikes, gates and channels that protect the area’s farms, cities and homes.
While the overabundance of water presents the Netherlands with many challenges, it also makes the country the world’s second-largest exporter of agriculture, surpassed only by the United States. Known for its sustainable and efficient farming practices, the Netherlands is expected to play a powerful role in the drive to feed the global population as it expands in the years and decades to come.
“In Holland, we are used to extremely high levels of production,” says Marc van Rijsselberghe, a farmer on the Dutch island of Texel. “On a hectare of land, our country can produce about 80 tonnes of potatoes. In the rest of the world, they would be very happy with just 15 to 30 tonnes.”
Van Rijsselberghe is only too aware of the threat that rising sea levels pose to this picture. “We have seen the production of potatoes go down in areas where the sea level is rising and the salt water is intruding,” he says. “In the coming 20 or 30 years, we will have somewhere around 150,000 hectares of land being salt affected, and we will have to adjust our crops to other options that can cope with a lot more brackish water.”
With this in mind, Van Rijsselberghe set out to identify crops that can grow – or even thrive – in the presence of salt water. “The biggest study on salt tolerance in plants was carried out by the University of Arizona, using one potato variety, about 40 years ago. They concluded that at only 2 deciSiemens – that’s 1% seawater – a potato plant will die.
“But I said, ‘That’s not true. I will try to murder as many plants as possible with brackish water and then see which ones survive.’ I built a facility that did just that – and in the end, I found potatoes that can grow on 50% sea water… and the whole world exploded.”
Van Rijsselberghe’s team now helps farmers around the world to grow salt-and drought-resistant crops, from America, South Africa and Kenya to Vietnam, Bangladesh and Pakistan. His solution doesn’t only focus on the type of crops that a farmer should grow; salt stress is also found in the soil, he explains, so you need to adapt your fertilizing, harvesting and irrigation methods as well.
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Novel technologies and approaches – from the planting of salt- and drought-resistant seeds to the use of drip irrigation to target a plant’s roots directly – can help address a number of issues caused by salt stress. “It’s about having the right practices, having the right attitude, standing your ground and adjusting your techniques,” Van Rijsselberghe says.
Of course, it’s important to note that, like water, new technologies and expensive fertilization and irrigation systems aren’t equally distributed among the world’s agricultural regions. One can only work with what one has, making the most of the resources and innovations that are both available and affordable.
South Africa: the other extreme
While farmers in the Netherlands struggle to stem the tide there are millions of farmers around the world who would perceive a surplus of water as more of a pipe dream than a problem.
“Drought is not a new phenomenon in South Africa,” says Andrea Campher, Disaster Risk Manager at a local agricultural industry association. “It’s something that has been happening here for several years, and the situation is very dire. In March 2020, South Africa was declared a drought disaster area nationally, so our farmers are very proactive and progressive when it comes to dealing with drought.”
In the country’s Western Cape, farmers are experiencing their fifth consecutive year of crippling drought. Their coping strategies vary depending on the commodities they farm, ranging from conservation farming practices such as no-till and the use of cover crops, to the targeted planting of drought-resistant crops.
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For Phillip Retief, owner of a 5,000-hectare wine estate in Robertson, South Africa, the drought has honed his farming practices and highlighted the need for technological innovation. “Throughout the farm, we use probes – sensors buried half a meter to a meter below the surface – to measure the moisture of the soil. Every farm manager and director has access to that data on his mobile phone, so we can see exactly when and where we need to irrigate.”
In response to the drought, Retief has also installed water meters at every pump station, to monitor the amount of water that goes to every block of land. “Yes, a sandy soil will need more water than a clay soil, for example,” he says, “but we can use these figures to enhance what we already know from the probes.”
Because Retief’s land lies in a naturally arid area, his vineyards get their water from a nearby holding dam, via a well-established water channel system. Every hectare of land is allocated a specific amount of water, and for the past two years, that allocation has been cut by 50%. To preserve the quality – albeit not the quantity – of his yield, Retief has resorted to cutting off half of his grapes before they begin to ripen. Like many other farmers in South Africa, he has also learned to work more efficiently with the water that he has, applying it more sparingly and in a more carefully timed and finely targeted manner.
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In the end, the future of agriculture and our world’s food supply will likely come down to those who can adjust their techniques and employ new innovations to adapt to current conditions. As Van Rijsselberghe points out with a smile, plants have no choice but to stay where they are and adapt if they want to survive – and farmers, too, must adjust quickly to survive in a world that is rapidly changing.
“We need to learn a lesson from the plants and stay put – stand our ground,” he says. “Instead of resisting the situation we are in, we need to adapt to it and work with it. There is always a way.”
DID YOU KNOW?
Exposing plants to stressful conditions and then selecting the strains that survive thrive is a tried and time-honored scientific approach. While commonly carried out today, this method was nothing short of revolutionary around 80 years ago, when researchers for leading seed producer Pioneer Hi-Bred International, now part of Corteva, began exposing corn hybrids to moisture stress in order to identify plants that possessed naturally drought-tolerant traits. Their work kickstarted many decades of research into drought-resistance in plants, with many similar studies still being carried out to this day. Today, farmers depend the products of that original research, planning drought-resistant strains in water stressed regions of the world.