When water gives you lemons

This is a guest blog from partners involved in the Cranfield University ‘Increasing resilience to water-related risks in the UK fresh fruit and vegetable system’ research project

Taking refreshments at a restaurant at the top of Old Coach road in Limpopo Province in South Africa, one notices a map from the early 1980s hanging on the wall. This map indicates just how much things have changed in the area – especially the growth of irrigated agriculture. We are near the town of Tzaneen, and the core of commerce here is fruit production. Vast stretches of orchards attest to this fact if you look downhill from the restaurant. Thanks to technology (Google Maps in this instance); there is further evidence of how fruit production in the area has expanded since the 1980s. Notably, increases have occurred mostly adjacent to rivers, making it clear how water and fruit production are intrinsically linked.

The resilience of fruit producing catchments to water risks is not only important for national food security, but also for the reliability of international markets such as the UK who rely on countries like South Africa for fresh fruit supply.  The ‘problem’ is whether a growth in agricultural production over time is a sign of increased resilience or potentially signals greater exposure to a shock such as a drought.  A strategic question for the Tzaneen area, and one central to our research, therefore is: As a result of this growth, has fruit production (and therefore the local economy) become more resilient to water shocks over time or less resilient?  Yet answering this question leads us away from simple ‘more/less’ thinking to a much more complex picture of a changing field of possibilities and outcomes as the following three topics of water management hint at.

The beauty and curse of water efficient production

One would be forgiven for thinking that expansion of production area has resulted in higher demand for water resources, a statement that is partly true. The flip side is that production has become increasingly efficient resulting in water savings, ‘freeing up’ water for an increase in irrigated area. Evidence suggests that rainfall amount and patterns, and drought cycles have largely remained unchanged, while water-consuming operations have increased over time. Production technology has changed in leaps and bounds over the same period. For instance, producers have shifted from flood irrigation to overhead sprinklers, then to microjet sprinklers, and now the current shift in avocado production in the Tzaneen area is to move towards drip irrigation. A citrus farmer in the Olifants catchment suggests that a shift from flood to microjet sprinkler reduced his irrigation water applications by about 50%, and shifting from microjet to drip has ‘saved’ him a further 30%. Given that water is allocated (via farm licences) on a per hectare basis and allocations are based on the less efficient irrigation practices and technologies of the 1960’s, fruit producers should have achieved water gains from these increases in irrigation efficiency. But precisely how higher water efficiency and increased area of production have impacted on catchment water stress over time is not yet fully understood.

Second, groundwater also plays an increasing but unquantified role in fruit tree irrigation. Groundwater irrigation supply at farm level is supposedly through registered boreholes, but evidence suggests that groundwater abstraction is generally not metered at farm level, nor monitored at a sub-catchment level. So there is little knowledge of groundwater abstraction and recharge rates over time and little understanding from the contribution groundwater makes on total farm water supply and overall catchment water stress.

On the role of water policy and pricing

Third, despite noble intentions to improve water management, the unintended consequence of the ‘use-it-or-lose-it’ policy[1] adopted in 2013 is that it further incentivises farmers to use as much of their water allocations as possible. Since fruit production is primarily a profit-making business, producers who save water by using less than their allocation face double jeopardy as they not only pay for what water they did not use, but lose out on potential profits they would have incurred had they maximised production operations to match farm water allocations. Furthermore, policies prohibiting water trade between water users imply that a farmer who uses less water than allocated cannot sell the saved water to other users and therefore does not derive financial returns for this neighbourly practice. In seeking to maximise returns, producers are rationally responding to a policy that encourages them to be ‘efficient’ at consuming more and more of their water allocation. In addition, the cost of water is low in comparison to other inputs (such as fertiliser and energy) and farmers pay a fixed amount irrespective of their water consumption. This also incentivises farmers to increase area under production, and use any water savings gained from being water efficient.

In conclusion – more or less resilient?

So, have the Tzaneen fruit growers become more resilient to drought shocks?  Our thinking is that a complex field or ‘envelope’ of efficiency/resilience is at work.

On the whole, rising production in fruit tonnage over time, despite recent droughts is evidence of an enhanced ability to cope with water scarcity.  But the three major ‘problems’ are that; a) catchment consumption may have ratcheted upwards leading to far less headroom between water supply and demand; b) unmonitored use of groundwater irrigation might be used to stretch farm water supply and expand area under fruit production, further reducing chances of resilience during droughts when rainfall and groundwater recharge is low and c) current water policy does not promote a market-driven regulation of demand and transfers of water savings to other sectors. The latter means farmers and sectors cannot inter-trade their water efficiency gains in an economically efficient way.

What is clear is that resilience and water efficiency of an individual fruit producer at a farm level is complex and varies from farmer-to-farmer and that farm level water efficiency and resilience cumulatively has considerable impact on catchment resilience. We do not have all the answers yet, but evidence suggests that Tzaneen fruit producers have become more water-efficient and more resilient to water shocks, but the catchment-wide land-water-crop system is still vulnerable and more can be done to enhance resilience at the catchment scale.

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The project, “Increasing resilience to water-related risks in the UK fresh fruit and vegetable system”, is funded through the Global Food Security’s ‘Resilience of the UK Food System Programme’, with support from BBSRC, ESRC, NERC and Scottish Government. The UK Food System Resilience Project looks to interrogate quantitatively and qualitatively water efficiency and related practices before, during, after and over successive droughts at a farm, catchment and national level; and understand how this relates to resilience of fresh fruit and water supply in South Africa.

[1] http://www.dwa.gov.za/Documents/NWPR.pdf