Solar irrigation: A game changer for climate resilience in agriculture

Originally published in Africa’s Voice on Water (AVOW) Magazine Volume 3 (Pages 18-19)

There is a rapidly growing trend towards adopting solar-powered irrigation systems as a critical adaptive strategy by smallholder farmers in sub-Saharan Africa. The El Niño phenomenon has intensified food and water insecurity across southern Africa, including Zambia, resulting in an increase in the adoption of solar-powered irrigation pumps as a means to mitigate these challenges and protect vulnerable populations from malnutrition.

Solarising irrigation at scale implies less reliance on the national grid for energy for food production. Additionally, introducing solar pumps has brought energy to remote places, enabling farmers to grow crops and attain food security. To take advantage of this, Zambia has eased restrictions on importing renewable technologies like solar panels. This is to counter the effects of gridded power rationing, “load shedding”, which worsen under El Niño conditions.

Despite the increased adoption of solar irrigation, the solar pump value chain in Zambia faces significant challenges, including:

• Providing irrigation equipment that is appropriately scaled for the heterogenous farming units in Zambia;
• Unmonitored increased groundwater usage and extraction in the Chibombo and Chongwe regions;
• Gaps in knowledge and capacity between the borehole drillers, and;
• Disharmony and poor coordination among the value chain players.

Our site visits in a selected few solar pump farms within a 100 km radius of Lusaka revealed the looming dangers associated with poor monitoring of boreholes and a lack of capacity in correctly sizing solar pumps for the different farming units. We believe that the impacts of continued and unmonitored groundwater abstraction will have severe future effects on water availability. Research has shown that utilising soil water for food production has dire trade-offs on surface and groundwater resource depletion, potentially leading to global crises.

Since the El Niño phenomenon affects water, food, energy, health, and the environment, coordinated approaches are required to maximise the benefits of the solar pump. This ethos of coordination builds resilience across multiple fronts by adopting a spectrum of adaptation strategies. We envision multi-stakeholder coordination including the Ministries of Agriculture (MoA), Green Economy & Environment (MoGEE), and Small and Medium Enterprises. A nexus approach to optimising the smallholder irrigation value chain is required to tackle these compounding risks. The MoA could be tasked to develop crop suitability maps, whilst the MoGEE, through its water agencies (such as the Water Resources Management Authority) could create maps of groundwater availability and suitability. These maps would guide drillers on where and how to access groundwater, potentially enhancing the utility of fossil aquifers. Additionally, the Zambia Meteorological Department could provide tailored climate information services to the farmers. When coupled together, the three components enable:

1. Tailored crop production that is adapted to the environment, thereby reducing the need for irrigation,
2. The integration of climate information services with scalable, adaptable agricultural practices that optimise water management, enhance soil moisture retention, and reduce reliance on irrigation,
3. Sustainable groundwater use by adapting (i) and (ii) to minimise irrigation demands through tailored crop production and climate-smart practices, these components contribute to improving groundwater management and sustainability.

Subsequently, private and public partnerships can catalyse change from the bottom up. For example, the International Water Management Institute (IWMI), NDKAY Zambia and the CGIAR Food Systems Accelerator are working to enhance sustainable water management practices in Zambia. Their efforts are based on technical capacity-building initiatives and knowledge exchange, promoting best practices such as appropriate pump-to-borehole synergy.

We recommend sector integration to minimise trade-offs and enhance synergistic efforts that foster growth across the water, energy, environment, nutrition, and health sectors.This integration will enhance policy coherence, planning, and contextual decision-making, targeting the appropriate learnings for each value chain player. We also advocate for increased access to decision support and other digital tools that enhance water productivity. These tools assist all value chain actors improve water accounting through better irrigation scheduling and borehole-pump sizing. The latter offers farmers an estimated pump size that matches their water sources. By embracing these strategies, we can ensure sustainable development and resilience in the face of environmental challenges.

Featured image: Dr Tinashe Dirwai (IWMI) and Jonathan Mwewa (Ndkay Zambia) in the field at Dorolyne Farm, Chongwe District, Zambia discussing the prospects of solar irrigation in the face of El Niño. Credit: Mahlatse Nkosi/IWMI

Authors

• Tinashe Lindel Dirwal, Regional Researcher, International Water Management Institute (IWMI)
• Mahlatse Nkosi, Research Officer – Inclusive Agricultural Finance, IWMI South Africa
• Dennis Jnr Choruma, Regional Researcher – Land, Water and Soil Solutions, IWMI South Africa

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