Navigating the Water Crisis
Water is our most precious natural resource — and also one of our most threatened. Here’s how agriculture is working to protect it.
The simple truth is that the crops that nourish and clothe us need water to grow. Of all the water on Earth, just 0.7 percent is available for agriculture.1 With a global population expected to reach 9 billion by 2050, farmers must find ways to feed more people using the same amount of land and water.2 This challenge can only be met by producing more crop per drop.
Modern farmers are rising to meet this formidable challenge. Water use has dropped from its peak in the 1980s, and crop yields per acre have seen significant improvement. It’s a step in the right direction; but as stewards of the land, farmers understand there is still progress to be made. Here are a few of the ways the agriculture community is increasing productivity and water efficiency.
Historically, farmers have made decisions about when to irrigate based on visual inspection of the crop or feel of the soil. However, modern farmers can control their irrigation systems based on real-time weather and soil conditions.
For example, the most advanced irrigation systems receive signals from local weather stations calculating evapotranspiration (the amount of water lost to the atmosphere) by monitoring temperature, solar radiation, humidity and wind velocity. This means an irrigation system can water crops based on how much moisture is lost from soil and plants to the atmosphere.
Soil moisture sensors mimic what roots are experiencing under the soil surface, telling farmers when it’s time to irrigate or hold off on watering. Data is wirelessly transmitted to farmers’ phones or computers for review, or can automatically trigger irrigation application.
By accurately predicting and responding in real time to crop moisture needs, farmers can significantly improve the efficiency of water and energy use, greatly reducing soil erosion and nutrient loss caused by overwatering.
The nutrients farmers apply to spur crop growth can dramatically boost yields. By increasing the amount of food produced without increasing the amount of land or water required, nutrients are a major component of agriculture. But farmers have learned there is a limit to the productivity benefits of nutrient applications — for example, applying more nitrogen does not always mean harvesting more bushels.
Responsible nutrient management requires balancing the amount of nutrients applied and the amount the soil can retain. Preventing nutrient loss protects water quality by minimizing runoff, and it also helps farmers by enhancing profitability through reduced fertilizer costs and improving soil quality by increasing nutrient retention.
Remote sensing uses aerial imagery from satellites or drones to gauge nitrogen needs using properties of light. Soil and crops reflect light differently depending on their nitrogen content. Using infrared and near-infrared sensors, drones and satellites measure these reflections and turn them into quantifiable data. Farmers can use this information to plan variable-rate fertilizer applications — that is, strategically applying fertilizer when and where it is most needed.
Buffer strips are planted between cropland and water bodies and provide multiple environmental benefits. These strips consist of natural vegetation that acts both as a filter for escaping nutrients and as a stabilizing force for stream banks. By absorbing nutrients and pesticides and trapping sediment, buffer strips can protect water quality. They also provide a habitat for wildlife.
Some of the biggest gains in sustainability and in yield potential come from applying nutrients closer to the time crops use them. This goes a long way toward reducing over-fertilization and nitrate runoff, while optimizing production. Farmers can use tools like tissue testing, which involves taking random plant samples from a given field and having them tested in a laboratory. The lab report gives farmers a reading of current nutrient levels, which helps them apply only the nutrition crops need at the appropriate rates.
Just the beginning
There are many other ways farmers are working to conserve and protect water, including minimizing drift from fertilizer applications, planting cover crops to decrease soil erosion, and employing less-invasive soil tillage methods to keep nutrients and fertilizers in place.
New seed technologies are helping protect water, too. Seed with insect control built into its genetic makeup minimizes the amount of pesticide needed later. And drought-tolerant seed can help farmers curb the amount of water their crops need while still yielding the same amount of grain.
That’s just a snapshot of how modern agriculture is working to preserve the integrity of our water supply. The industry continues to develop more sustainable methods to plant, grow and harvest crops. Agriculture is navigating the way to preserving a plentiful, clean water supply so farmers can grow the food that nourishes us all.
Visit nationalgeographic.com/unchartedwaters to test your water knowledge and spread the word by sharing your results.
- Freshwater Crisis http://www.nationalgeographic.com/freshwater/freshwater-crisis.html. Accessed July 27, 2016. See more at: http://www.Winfield US.com/Beyond/index.htm#beyondtheacre
- World population projected to reach 9.6 billion by 2050. United Nations Department of Economic and Social Affairs, June 13, 2013. See more at: http://www.un.org/en/development/desa/news/population/un-report-world-population-projected-to-reach-9-6-billion-by-2050.html. Accessed July 27, 2016.