Water: Agriculture’s Most Precious Resource
Farmers, the world’s greatest users of water, recognize the need to conserve water, especially in the face of a rising population and climate change with prolonged droughts and extreme temperatures. Agriculture uses three times the amount of water it did 50 years ago, and by 2050 it will need a further 19 percent.
Fifty years ago, there were less than half the current number of people on Earth. They consumed fewer calories and ate less meat, so they required a third of the water we need today. Now the world’s population is approaching 8 billion, our consumption of meat and vegetables has gone way up and there is more competition for water from non-food crops and other industries.
Water conservation not only helps farmers produce more food with less water, it can help them cut costs. In 2006, the U.S. Department of Agriculture predicted that if the agricultural sector improved water efficiency by just 10 percent, farms could save upwards of $200 million per year.
On the flip side, with water scarcity, food prices go up. When there is a drought in California, for example, a consumer could pay up to $15 more for every $100 in food.
Fortunately, farmers’ efforts to conserve water are paying off: it only takes half the irrigated water to produce cotton today compared to 20 years ago. But efforts must be ongoing as plants need considerable amounts of water to grow. That’s because they are composed of about 90 percent water, which is needed to maintain their structure and for photosynthesis to occur. For instance, nearly 2,500 liters of water are needed to grow one kilo of rice alone.
Farmers today are conserving water in a number of ways, such as using herbicides and herbicide-tolerant biotech crops, which allow for no-till farming so soil doesn’t need to be turned over and can retain moisture. With no-till farming, farmers can increase soil moisture content by as much as 24 percent. Soil moisture is important since plants take in water through their roots. In 2050, the International Food Policy Research Institute (IFPRI) predicts no-till farming, coupled with irrigation, will increase global maize yields by 67 percent.
Herbicides also assist with water conservation by preventing weeds from competing with crops for water and allowing for zero tillage. For example, research has shown that no-till weed control in olive groves with herbicides increases soil moisture by 25 percent. Similarly, in Kazakhstan, no-till wheat, combined with herbicide use, has yielded up to three times more grain than conventionally cultivated crops while conserving soil moisture.
Farmers are doing their part to protect agriculture’s most precious natural resource. Plant science will continue to help them along the way.