How farmers can adapt to climate change through improved irrigation water management strategies, technologies, and practices
Imagine a world where the water that once reliably nourished crops becomes increasingly scarce and unpredictable. This is not a distant future scenario—it's the present reality for farmers across the globe.
As temperatures rise, crop evapotranspiration rates increase, resulting in reduced soil moisture and higher crop water demand 5 .
These challenges are particularly acute in developing countries where water scarcity already persists and agricultural water consumption accounts for up to 80% of total water usage 7 .
The critical question facing global agriculture is straightforward yet profoundly challenging: how can farmers continue to grow the food our growing population needs with less predictable water supplies? The answer lies in building farm-level capacities in irrigation water management—equipping farmers with the knowledge, technologies, and strategies to adapt to our changing climate while maintaining productive and sustainable agricultural systems 8 .
To appreciate the innovations in irrigation management, it's essential to understand three key concepts that govern water dynamics in agricultural systems.
Evapotranspiration (ET) represents the combined water loss from soil surface evaporation and plant transpiration . This process connects directly to plant productivity—as plants open their stomata to take in carbon dioxide for photosynthesis, they inevitably lose water to the atmosphere.
When water becomes scarce, plants protect themselves by partially closing these stomata, reducing both water loss and photosynthesis . This fundamental tradeoff explains why total dry matter production in plants is typically linearly related to evapotranspiration.
Water Use Efficiency (WUE) has become a critical metric in agricultural water management, defined as the ratio of the minimum feasible water required compared to the observed amount of water usage for a given level of output 5 .
Recent research reveals significant opportunity for improvement—the average irrigation WUE in the United States is approximately 72.6%, meaning farmers could potentially reduce water use by about 18% without affecting yields 5 .
Deficit irrigation involves applying less water than crops theoretically require during specific growth stages to improve water-use efficiency 2 .
When strategically applied to drought-tolerant crops or during less sensitive growth periods, this approach can maintain satisfactory yields while significantly reducing water consumption 4 .
However, it requires precise understanding of crop water needs and carries risks of promoting salt accumulation in soils if not carefully managed 2 .
A groundbreaking three-season study conducted on citrus trees in clayey soils at Benha University, Egypt, provides compelling evidence about how different irrigation systems perform under challenging conditions 2 .
The research team designed an experiment to compare traditional flood irrigation (FI) with various drip irrigation systems: full surface drip irrigation (FFDI), full subsurface drip irrigation (FSDI), and their deficit irrigation counterparts (DFDI and DSDI) that applied 25% less water 2 .
The researchers established a carefully controlled field experiment with 20-year-old Navel orange trees, dividing them into treatment groups with triple replication 2 .
The study yielded several important findings with significant implications for agricultural water management in water-scarce regions 2 .
| Irrigation System | Water Savings Compared to Flood Irrigation | Yield Increase Compared to Flood Irrigation | Water Use Efficiency (WUE) |
|---|---|---|---|
| Full Subsurface Drip (FSDI) | 31.58% | 8.70% | 58.87% improvement |
| Full Surface Drip (FFDI) | Moderate savings | Moderate improvement | Moderate improvement |
| Deficit Subsurface Drip (DSDI) | 48.68% | Yield reduction | Improved per unit water |
| Deficit Surface Drip (DFDI) | 45.82% | Yield reduction | Improved per unit water |
| Traditional Flood (FI) | Baseline | Baseline | Baseline |
The superior nutrient uptake with subsurface drip systems demonstrates another advantage of precise water application—farmers can achieve better results with the same amount of fertilizer, reducing both input costs and environmental impacts 2 .
Perhaps most importantly, the research documented the long-term impacts of these irrigation systems. While deficit irrigation achieved the highest water savings, it also caused "the highest deterioration rates over time under both irrigation systems for all studied parameters" 2 .
Modern irrigation research relies on sophisticated tools and methodologies to gather precise data and develop effective water management strategies.
These tools enable researchers to monitor soil water content at multiple depths down to 100 cm, providing crucial data on how water moves through the soil profile and is extracted by plant roots 2 .
Essential for measuring sodium (Na⁺) and potassium (K⁺) ions in water and plant digestates, helping researchers understand nutrient uptake and salt accumulation in soils 2 .
Used to determine electrical conductivity in water and soil paste extraction, providing critical measurements of salinity levels that directly affect crop health and yield 2 .
Developed by the FAO, this software program computes reference evapotranspiration and net irrigation water requirements for various crops, helping farmers and researchers optimize irrigation scheduling based on local conditions 3 .
A sophisticated tool for designing and simulating the hydraulic behavior of pressurized pipe networks, enabling researchers to develop efficient sprinkler and drip irrigation systems tailored to specific field conditions 3 .
Advanced algorithms from NASA and USGS analyze high-resolution satellite data to track irrigation expansion and water usage across vast agricultural regions, providing valuable insights for large-scale water resource management 6 .
The research evidence points to several concrete strategies that farmers can adopt to build resilience against climate change through improved irrigation management.
Transitioning from traditional flood irrigation to pressurized systems like drip or sprinkler irrigation represents one of the most effective adaptation strategies 3 8 .
As demonstrated in the Egyptian study, subsurface drip irrigation systems can reduce water use by over 30% while simultaneously increasing yields 2 .
Climate adaptation requires acknowledging that some crops are better suited to water-scarce environments than others.
Research indicates that selecting appropriate crop patterns for wheat, barley, potato, and sugar beet can significantly save irrigation water while maintaining food production 3 .
Introducing drought-resistant crop varieties that maintain productivity with less water represents another key strategy 8 .
Improving the soil's capacity to retain moisture directly reduces irrigation requirements.
Techniques such as conservation tillage, organic matter addition, and using super absorbent polymers like hydrogel can improve water holding capacity, extend irrigation intervals, and increase water use efficiency 7 8 .
On-farm water harvesting through ponds, tanks, or direct groundwater recharge creates reserves that allow farmers to capture excess rainfall during wet periods for use during dry spells 8 .
This approach builds resilience against increasingly variable precipitation patterns and helps farmers maintain irrigation during drought conditions 7 .
Building farm-level capacities in irrigation water management is not merely a technical challenge—it requires an integrated approach that combines technological innovation, knowledge transfer, supportive policies, and economic incentives 4 8 .
As climate change continues to reshape our agricultural landscapes, the imperative to adopt more efficient, responsive irrigation practices becomes increasingly urgent. The Egyptian citrus study and related research point to a promising path forward—one where farmers become active managers of precious water resources rather than passive victims of climate variability 2 .
The transformation of agricultural water management represents one of our most powerful tools for building food system resilience in a changing climate. By equipping farmers with the knowledge, technologies, and strategies outlined here, we can cultivate not just crops, but sustainable agricultural systems that thrive despite the challenges ahead.
The journey toward climate-resilient agriculture begins with a single drop of water—precisely applied.