Producing more, with less: Water use efficiency in irrigation

Optimizing water use in irrigation

Agriculture accounts for 70% of all global freshwater withdrawals. Our growing global population requires more food to feed it. The Food and Agriculture Organization of the UN (FAO) estimates that 60% more food will be needed by 2050. This will inevitably put more strain on our freshwater resources, with estimates that to meet this demand irrigated food production will increase by more than 50% by 2050.

Furthermore, effects of climate change on weather and water patterns threaten two-thirds of the world’s population with water scarcity by 2025. There are concerns these water shortages could lead to conflict over freshwater resources, which could ultimately threaten global food security.

At Yara we believe two critical strategies – adopting effective irrigation systems and optimizing crop nutrient management – can boost agricultural productivity while also enhancing water use efficiency.  

Water use efficiency, and how this can be optimized, has become an area of focus for Yara. 

“In simple terms, water use efficiency is the amount of crop yield produced per unit of water consumed by the plant. This is a very important topic in crop production.” 

Dejene Eticha, Senior Scientist, Yara Agronomic Research and Development. 

Effective irrigation systems

Yara advocates for a transition from surface irrigation towards pivot, sprinkler and micro-irrigation systems which increase water efficiency. Drip irrigation systems, for example, deliver water straight to the plant's root zone, minimizing evaporation and runoff losses.

Traditional irrigation practices like flooding exhibit water efficiency levels of 30-40%, furrow irrigation ranges between 55 -70% water efficiency, while dripline can reach up to 95%. Furthermore, drip irrigation excels at maintaining consistent soil moisture levels, unlike other systems that frequently oscillate between excess and insufficient water conditions. This stability promotes healthier plant growth and more effective nutrient absorption.  

Optimal crop nutrient management 

Yara’s scientists have found that optimal nutrient supply not only boosts yield but also helps plants make the most of water supply.

A study on fertigation of tomatoes – a method that combines nutrient and water application – found a 19% growth in yield, a 36% reduction in water consumption, and a 46% enhancement of water use efficiency. Similarly, in potato cultivation, drip irrigation resulted in a 31% reduction in water consumption per ton of crop compared to pivot systems, plus a 10.5% profit increment after the initial investment. 

Optimized fertilizer application promotes the development of deeper and more vigorous root systems. Adequate nutrient levels enable roots to reach moisture reserves in the deeper soil layers, reducing reliance on surface soil and decreasing the need for frequent irrigation, thus conserving water. Moreover, an optimal nutrient supply increases crop biomass, reducing soil evaporation by shielding it from direct sunlight and wind, thereby enhancing water use efficiency. 

Yara's scientific trials on wheat have demonstrated that optimal nitrogen levels not only lower soil evaporation by threefold compared to nitrogen-deficient crops but also enhance wheat yields by up to 2.5 times with similar water use. These outcomes emphasize the vital relationship between nutrient management and efficient use of water. 

Producing more, with less 

Fertigation not only maximizes plants uptake, but it also reduces losses to the environment both through soil leaching and greenhouse gas emissions into the air. “It is little known that one of the main sources of emissions from our industry comes from field emissions of methane from paddy rice cultivation. Converting such systems towards more efficient irrigation and fertigation system is strongly in focus,” says Martin Debaig, Fertigation Director & Calcium Nitrates Product Manager. 

Martin adds that Yara is focused on ensuring that the transition towards more efficient irrigation systems – which have become a requirement in more and more places around the world due to the changing rainfall patterns – is complemented by simple dissolving systems in order to drive the industry at scale towards fertigation. “This is critical to develop a nature-positive food system, producing more with less,” he adds.