Agriculture accounts for almost 70% of withdrawn water for human use. 40% of all crops grown in the world are produced using irrigation. By 2050, the world will need to find a way to cope with the additional 2 billion people that will need to be fed with the same amount of land and with less water available.
We need to find solutions to a large number of challenges that threaten the sustainably of food production. Water is a critical element in this equation, and its correlation with soil and other agricultural inputs needs to be comprehensibly addressed.
I would like to talk about a product I am very familiar with: bananas, which by the way are 80% water. For years, internationally traded bananas have mainly been sourced from Latin America. Ecuador, Costa Rica, Guatemala, Colombia and Honduras have become the main sources of conventional bananas for Europe and North America. On the other hand, Peru and the Dominican Republic are large producers of organic bananas. All these countries have very different characteristics, including soil types, rainfall patterns and pest and diseases.
Costa Rica has intensive precipitation almost year round with few but very well defined dry periods. The combination of high humidity with very high temperatures results in the perfect environment for the development of funguses, including “black sigatoka”, one of the major threats to growing bananas. In order to control this fungus, farmers in Costa Rica require almost-weekly applications of fungicides, applied through spraying planes. Aerial spraying is highly questioned in some markets, particularly in Europe where it is basically banned. However, high technology and precision agriculture certainly allow banana producers to control the risk of contamination (including water contamination) while protecting crops adequately.
Organic banana plantations in Perú enjoy opposite conditions. Grown in dry areas to avoid the presence of funguses (and nematodes), organic bananas require intensive irrigation. In many cases grown by smallholders without the technical or economical resources to invest in modern irrigation systems, organic bananas rely on flooding irrigation, clearly a non-sustainable method. Flooding stresses the plants by not providing the water when needed and over irrigating it during short periods, with direct impacts on productivity. In addition, flooding can also lead to runoffs of fertilizers, soil amendments and pesticides, provoking serious pollution problems. Soil erosion, which affects all types of farming systems, also contributes to increase water pollution.
Water supply is a constraint for irrigated agriculture. In many regions renewable water supplies have been overused and water depletion is a real threat to farmers. Too much or too little are both undesirable when we talk about irrigation. It is important to understand the real water needs of the plants. Most farmers do not have the know-how or technology to measure soil moisture or identify the water capacity intake of the plants.
Like for most of the challenges in this world, the solution relies on the cooperation of the different players. Large plantations usually have resources and capacity to identify the most efficient agricultural practices which can be in many cases replicated by smallholders. However, the participation of other players such as academia and the manufacturers of crop protection products and fertilizers could close the circle by sharing -- for each crop and production system -- responsible and efficient methods which optimize the use of natural resources, including water.
Funding is also critical, as smallholders may not have the resources to adapt their production systems to the new challenges. To this end, the support from governmental and non-governmental organizations, including developing agencies, is extremely important.
Finally, consumers need to understand the supply-demand model. Producers will have less access to water and other inputs (synthetic fertilizers will also be limited in the future as oil becomes more and more expensive and rare), so we may need to agree on recognizing the real value of food.
The views expressed are solely those of the author and do not necessarily represent the views or positions of WWF.
You can also read this blog post on Coca-Cola’s Unbottled.