Food Self-Sufficiency is Delusional. Or is it?

  • No, it is not. Hydroponics is the answer. The method may be a bit scientific but is ideal for our clever youth and turns a good yield from less land and less water.

Food self-sufficiency is a noble aim of the government which has banned imports of many crops to stimulate local production. But although rainfall has been good in 2021/22, records show that in our water-scarce lands, it varies between 200mm to 600 mm pa between October and March.

Currently, 85 million cubic metres (MCM) are allocated/consumed by farming with everything else being about 100 MCM (2016). So given the very finite nature of water resources, where is the additional water needed coming from to support food self-sufficiency?

Assuming agricultural output must double for Botswana to become self-sufficient, then very crudely must the volume of water consumed by farming also double. The sector will need >170 MCM. Is that possible? What can we do? Let’s set this familiar scene. Fifty-thousand registered farms are employing 20% of the population. Though not technically poor, there are clusters of poverty headcount ratios of between 20% and 45%. Women are predominant in horticulture and small stock. Agriculture productivity remains divided, relatively high for a few commercial farmers 3 T/Ha and very low for the majority of smallholders and seasonal farmers at 0.3 T/Ha. Cereal production of circa 30,000 tons satisfies 10% of the demand of 320,000 tons. Soil fertility is classified poor to fair with only 5% of the land fertile – implying higher use of fertilisers. To complete the picture, the system of land tenure remains an issue.

The hard reality is that to produce 320,000 tonnes of maize needed to fully substitute imports, 100,000 Ha of fertile land and 500 million cubic meters (MCM) of water will be needed, assuming maize needs 500 mm of water. In drought years of 300mm or less of rainfall, 200mm or 200 MCM of additional water needs to be supplied, but from where? Moving onto potatoes, as this has also been in the news, Botswana consumes 10 kg per person per year, which is 250,000 tons for the population. Each kilogram of potato requires 250 litres of water, so to become self-sufficient in potatoes, 6.25 MCM would be needed.

Let us now consider the economics of food security. We are food import-dependent and ranked 74/113 on the Global Food Security Index (GFSI) for 2021. It is noteworthy that Botswana was ranked 54th in 2016, which is sad because it means we are getting more food insecure (Source: At the subnational level in cities, towns, urban villages and rural areas, the proportion of the population experiencing moderate to severe food insecurity was 31.70%, 46.60% and 65.50% respectively, while those experiencing severe food insecurity only was 11.90%, 17.50% and 33.10% for the same areas (Stats Botswana).

The key criteria of GFSI are Affordability, Availability, Quality and Safety, Natural Resources and Resilience. It is important to note that Botswana is ranked 103rd for Natural Resources and Resilience, which is climate change resilience, and land and water management.

Botswana must be mindful that South Africa is ranked 70th and falling rapidly in the global food security index while Zambia, Malawi and Mozambique are ranked 105, 109 and 111 respectively. It is almost certain that there will come a time when SA will not be able to export food and when SADC face a food crisis. The national food security policy is correct, even more so because of rapidly rising food prices.

If we return to the economics again, we see that food imports are about $1 billion, accounting for 20% of all imports and 7% of GDP negative 2020. Agriculture is 1.8% of GDP, 15.7 billion or $282m. This is 22% of total expenditure on imports plus local production. For every P100 we spend on food, only P20 stays in Botswana. So we have to put our government on the spot here and ask what the import substitution target is and what the strategy to achieve it is? The good thing is that savings on imports are a plus to our economy.

The starting point in our delusion is that we have more than enough water to grow all the food we need.  We have borehole water, but it is hardly infinite and is not all potable. Then there is rainfall harvesting, which would be good but it requires massive investment well that is beyond the reach of ordinary people. So how do we conjure up another 100 million cubic metres of water needed to achieve food self-sufficiency?

Then there is the issue of soil fertility. Most of the country has poor to moderate fertility, with only about 12% of the land being of good to high fertility but is already efficient tillage and is from where much of our food comes. It seems that we have to grow more food without extra water on infertile land. But there is something we can do to fill the gaps in food import substitution: Hydroponics.

Derived from the two Greek words hydro and ponos, meaning water and labour respectively, hydroponics (HP) is defined as a method of growing plants in water rather than in soil. Long back history, the Hanging Gardens of Babylon in the delta of the Tigris and the Euphrates Rivers of Mesopotamia may have been hydroponic. Today hydroponic cultivation has spread globally, from Hawaii to Holland and Chile to China. Hydroponics platforms may be horizontal or vertical, urban or rural,  grown in reservoirs, tubes and containers, in backyards or as huge agro-industries operated robotically. It requires a new mindset of applying plant sciences, production management and control.

Hydroponics infrastructure is measured in planting points and square metres, not hectares. An area of 100 m2 set up vertically will have 1 000 points and yield a reasonable family income. There are several different hydroponics systems, the most common being the Nutrient Film Technique (NFT), the Deep Water Culture (DWC) and the Drip System using Dutch buckets. In all HP systems, nutrients are fed to the plants in water which is normally circulated in closed systems to keep out light to avoid algae. Nutrients vary according to plant type, and may be synthetic or organic. It is a bit scientific but good for our clever youth.

The most common type of water quality instruments used in hydroponics is electrical conductivity (EC), pH, and dissolved oxygen (DO) metres. Power may preferably be photovoltaic. Water is supplied from a borehole if the system is commercial and shade netting required for protection from excessive heat and frost. Tubes may also be used, but temperature and air circulation controls are necessary. Plants may grow all year and are independent of the weather.

Let us not forget our pastoralists – the many cattle and goat farmers who pray for rain every day. The good news is that fodder can also be grown hydroponically. It is more nutritious – with 30% more protein than soil-grown grass. And hydroponics requires far less water needs. It would also give our suffering dairy industry a huge boost and – naturally – it would give a huge boost to the sustainability and reliability of stock farmers. It means they can go into the bank to borrow and say clearly what the output will be without the biggest risk factor, our weather, casting its dark cloud.

So there is no delusion about goals of food self-sufficiency for Botswana after all. We can produce tonnes and tonnes more food and consume less water and use less land than we do at present. All we need to do is to move to hydro