Balancing natural and human dimensions to improve climate resilience
Over the last few decades, demand for water has grown at twice the rate of population growth partially due to irrigation expansion. While water supply is in theory sufficient to meet increasing demand, spatial and temporal heterogeneity creates a mismatch between where water is and where we want it to be at any given time. Along with population growth, climate change is expected to further exacerbate seasonal and geographic differences in water supply and water demand. In Guatemala, water supply has decreased annually between 1950 and 2006 by 2.7% on average1, while irrigation demand has increased significantly in the same period.
Barriers to prioritizing irrigation expansion in developing countries
One approach to mitigate the impact of increased variability in precipitation is prioritized irrigation expansion. The use of irrigation systems can help ensure that crops receive proper amounts of water and nutrients during periods where crop water requirements exceed available rainfall. The challenge with irrigation expansion, particularly in developing countries, is that water rights are not well-defined resulting in large cash crop plantations consuming large amounts of water and smaller farms that would benefit from the practice often having limited access to the necessary infrastructure, financial credit, technical assistance, and market value chains.
Is irrigation expansion the right approach?
Several key factors are important in determining whether irrigation expansion makes sense. The demand for water varies by crop type, along with weather and climactic conditions such as temperature, solar radiation, and precipitation amounts. Additionally, some crops are more resilient to drought conditions and may be less impacted from limited water availability. Crops that require less water and are more resilient to climate extremes may become a priority for planting with less irrigation needs, while water intensive crops that are an important food source or economic priority may be deemed critical for irrigation expansion.
Irrigation expansion for smallholder farmers
In Guatemala, smallholder farmers control over 50% of agriculture land, but over two-thirds of irrigated land is dedicated to major exportation crops such as sugarcane, rubber, and oil palm. Staple crops such as beans, rice, and vegetables; and culturally important crops, such as coffee, are not typically grown by smallholder farmers. Obstacles to irrigation for smallholder farmers include a lack of access to irrigation infrastructure (water distribution and storage), limited surface water rights, and a lack of access to credit, technical assistance, and market value chains.2
The benefits of irrigation expansion for smallholder farmers and climate resilience
In a recent study we found that the benefit, through increased crop yields, of expanding irrigation access to smallholder farmers in Guatemala was nearly equal to the benefits that larger scale industrial farms would receive. Water storage would also allow irrigation and other water users to protect against prolonged dry seasons which are becoming more prevalent under climate change.
Overall, irrigation expansion has the potential to bolster local food supplies, support food security goals, and advance renewable energy targets. Reducing barriers to irrigation access for smallholder farmers could allow for an equitable and resilient future for communities in Guatemala and beyond.