Wastewater irrigation is an economical and high-in-nutrients option for even the poorest farmers. But, if untreated, the consequences for our health and the environment can be catastrophic. Discover the techniques that could transform agriculture as we know it, offering perhaps the most sustainable and efficient use of resources available today.
It’s not uncommon to see a Rwandan farmer at work tilling the land by hoe. Motorized engines are only slowly starting to be introduced into the country. The small parcels growing bananas, maize, sweet potatoes or even cassava roots that dominate the agricultural landscape belong to smallholders living off their land. In Rwanda, like many other developing countries, most of the produce is consumed domestically, but the country has high hopes for the future. An ambitious government initiative to reform the agriculture sector, known as Vision 2020, is leading the way for change. But to be successful, it must first address the water challenge.
For centuries, water has been the deciding factor between plentiful food and hunger or starvation. Irrigation emerged as a way for humanity to take control over the elements, reducing risk and increasing efficiency. Today, a staggering 70 % of the world’s freshwater resources are used in agriculture, with irrigation taking the largest share. Yet, surprisingly, only 20 % of farmlands are irrigated. These, however, supply 40 % of the world’s food – a testament to the groundbreaking impact of irrigation. On a more somber note, these figures are also a stark reminder of the insecurity that still pervades the sector.
Managing scarce resources
By 2050, when the population reaches nine billion, we will need to produce 60 % more to feed everyone, according to the Food and Agriculture Organization (FAO). To grow more, we need to irrigate more, but the Organisation for Economic Cooperation and Development (OECD) tells us that, by then, the strain on our water resources will have increased by an astounding 55 %.
Although there is enough water to meet this demand, overconsumption and the consequences of climate change can lead to water scarcity, land degradation and food shortage, especially in the least developed regions. Empowering farmers to better manage water is vital. If not, the poorest will suffer. Something needs to change and waste could hold the answer.
Water technology solutions
Wastewater ticks both the sustainability and efficiency boxes, but it’s not an innovative breakthrough. The truth is that for many rural communities, especially in developing countries, sewage and wastewater are often the only source of water for irrigation. Even when other options are available, small farmers value its high nutrient content, which lowers or even removes the need for costly fertilizers. This practice has become essential to the livelihoods of many poor people in Asia, Latin America and Africa, including Rwanda. But there is a darker side. If wastewater is not treated before reuse, it can contaminate the crops, surrounding land and water supplies. The health risk to farmers, nearby communities and consumers could be catastrophic.
Rwanda is just one of many countries for which untreated water is a problem. The country lacks technology for water retention. Its landscape is mountainous, which means that flooding and soil erosion are common. Together with increased urbanization, these factors contribute to the pollution of rivers and other water resources.