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鈥檚 surface 鈥 but it isn鈥檛 distributed equally. In many countries around the world, mankind is faced with either 鈥渢oo much鈥 or 鈥渢oo little鈥 water 鈥 and a decreasing chance of it ever being 鈥渏ust right.鈥
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 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鈥檚 productivity and, ultimately, the farmer鈥檚 profitability. And it isn鈥檛 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 鈥 including 90% of the bustling city of Rotterdam 鈥 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鈥檚 farms, cities and homes.
While the overabundance of water presents the Netherlands with many challenges, it also makes the country the world鈥檚 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.
鈥淚n Holland, we are used to extremely high levels of production,鈥 says Marc van Rijsselberghe, a farmer on the Dutch island of Texel. 鈥淥n a hectare of land, our country can produce about 80鈥痶onnes of potatoes. In the rest of the world, they would be very happy with just 15 to 30 tonnes.鈥
Van Rijsselberghe is only too aware of the threat that rising sea levels pose to this picture. 鈥淲e have seen the production of potatoes go down in areas where the sea level is rising and the salt water is intruding,鈥 he says. 鈥淚n 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.鈥
With this in mind, Van Rijsselberghe set out to identify crops that can grow 鈥 or even thrive 鈥 in the presence of salt water. 鈥淭he 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 鈥 that鈥檚 1% seawater 鈥 a potato plant will die.
鈥淏ut I said, 鈥楾hat鈥檚 not true. I will try to murder as many plants as possible with brackish water and then see which ones survive.鈥 I built a that did just that 鈥 and in the end, I found potatoes that can grow on 50% sea water鈥 and the whole world exploded.鈥
Van Rijsselberghe鈥檚 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鈥檛 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 鈥 from the planting of salt- and drought-resistant seeds to the use of drip irrigation to target a plant鈥檚 roots directly 鈥 can help address a number of issues caused by salt stress. 鈥淚t鈥檚 about having the right practices, having the right attitude, standing your ground and adjusting your techniques,鈥 Van Rijsselberghe says.
Of course, it鈥檚 important to note that, like water, new technologies and expensive fertilization and irrigation systems aren鈥檛 equally distributed among the world鈥檚 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.
鈥淒rought is not a new phenomenon in South Africa,鈥 says Andrea Campher, Disaster Risk Manager at a local agricultural industry association. 鈥淚t鈥檚 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.鈥
In the country鈥檚 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. 鈥淭hroughout the farm, we use probes 鈥 sensors buried half a meter to a meter below the surface 鈥 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.鈥
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. 鈥淵es, a sandy soil will need more water than a clay soil, for example,鈥 he says, 鈥渂ut we can use these figures to enhance what we already know from the probes.鈥
Because Retief鈥檚 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 鈥 albeit not the quantity 鈥 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鈥檚 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 鈥 and farmers, too, must adjust quickly to survive in a world that is rapidly changing.
鈥淲e need to learn a lesson from the plants and stay put 鈥 stand our ground,鈥 he says. 鈥淚nstead of resisting the situation we are in, we need to adapt to it and work with it. There is always a way.鈥
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 精东影业, 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.