African farmers starting to leapfrog “green revolution”…


Africa’s crop yields are only about 40% of the world average. This is despite more than half of Africa’s workforce being in agriculture, twice  as high as the world average. This means the productivity in Africa’s agricultural sector is only about a fifth of the world average, an enormous economic loss to the continent.

The impacts of this huge productivity shortfall include high levels of poverty (particularly in rural areas) and low levels of food security. Africa’s low agricultural productivity is the continent’s most urgent development challenge. Projections that the world will need at least 70% more food by 2050 confirm that rapid progress to increase crop yields is vital.

The standard advice given to African farmers has been to follow the methods of the so-called Green Revolution, which successfully increased crop yields in other continents, particularly Asia, from the 1970s onwards. Indeed, a large and well-resourced Africa-wide NGO builds this advice into its very name, the Alliance for a Green Revolution in Africa (AGRA).

However, whilst the Green Revolution did successfully raise crop yields by increasing the use of high-performance seeds and synthetic fertilizer, it was never as sustainable as its name implies. Unfortunately, synthetic fertilizer (which I will call NPK here for short) is one of the worst greenhouse gas emission culprits, responsible for 2.5% of the global total.

Furthermore, in many parts of Africa, including Ghana, application of NPK has been relatively ineffective in raising yields, reflecting the specific local soil, climate and application context. In many areas, NPK application has also contributed to soil and watercourse degradation.

Despite these problems with NPK, since there is a clear need to produce more food to feed the growing population, many have assumed there is no alternative to promoting high rates of NPK (alongside high yield seeds) to achieve this, and to just accepting the resulting financial costs and environmental damage. But this logic is flawed. It overlooks well evidenced and better ways to raise yields than simply promoting NPK use on its own as a fertilizer. This article documents one such alternative, effective organic biostimulant fertilizers.

In addition, the cost of NPK has risen dramatically. Since 2020, NPK prices have shot up, for example in Ghana by close to 5-fold (and close to 10-fold for farmers who in 2020 were receiving Government subsidised NPK). Whilst there are signs of some falls in NPK prices now, it is clear they will remain much higher than a few years ago. The agriculture academic research literature typically claimed a financial return for NPK (that is, the increase in profit farmers get from the yield increase it brings, less its cost) worth about one dollar for every dollar spent on NPK by sub-Saharan African farmers, before 2020 and the huge NPK price rise since that date. It is therefore obvious that the financial returns of NPK are now typically small or negative in the region.

It’s clear many African farmers understand this problem: for example, farmers are moving away from crops like maize, which have been thought to need heavy NPK use, to crops like soya and cowpea which do not, in order to improve their financial returns.

Negative financial returns for NPK applied on its own in the region mean government subsidy for NPK would be a waste of money, spending that will actually reduce overall economic output, in addition to negatively impacting our environment.

So what can be done to increase Africa’s food production to the levels needed to provide food security and keep up with population growth?

Fortunately, there is a very good solution available, of which a particularly effective example is HJA Africa’s Ghana-made liquid organic fertilizer for all crops, OFA (Organic Farming Aid). The solution is effective organic biostimulant fertilizers, a well proven technology to increase yields that has been used for decades in many parts of the world, though not much in Africa. Biostimulant fertilizers work differently from both NPK and standard organic fertilizers like manures, which put bulk nutrients, particularly nitrogen, into the soil for plants to absorb. Biostimulant fertilizers are catalytic, improving plants’ ability to uptake and make use of already present nutrients. This means they can be used in very small quantities.  OFA also increases positive microbial activity in the soil which improves soil quality, and gives pest repellent and fungicide benefits, a big bonus to the farmer.

I focus here on OFA as the example I know best, and the table below draws on research results from Ghana’s Council for Scientific and Industrial Research Savanna Agricultural Research Institute (CSIR-SARI) to illustrate outcomes for maize. Other research and our many farmer users confirm similar results for rice and other cereals, legumes like soybean and cowpea, tree crops like mango and cocoa, and vegetables and root crops.  The table shows costs and benefits in Ghana cedis and dollars.


  OFA OFA+50%NPK 100%NPK
Efficiency (weight of input used for season) 1 kg 176 kg 350 kg
Affordability (input cost) ₡68 ($6) ₡1384 ($123) ₡2678 ($238)
Profit increase 2160 ($192) ₡2880 ($256) ₡1689 ($143)
Returns (extra profit / extra cost) > 30:1 2.1:1  0.6:1
Sustainability? Very much better than 100% NPK Much better than 100% NPK Not sustainable
Case for use? Strong Strong None

The table is based on CSIR-SARI trials in 2021 and 2022 near Tamale in northern Ghana, on poor soils, with high yield maize.

The table shows that both OFA on its own, and OFA combined with 50% of the recommended amount of NPK, were far better value for money than using the recommended amount (“100%”) of NPK, and that the treatments with OFA gave big increases in profits. OFA gave financial returns of over 30:1 on its own, or 2.1:1 combined with 50% NPK, compared to just 0.6:1 for NPK on its own.  These results show there is currently no case for Ghanaian farmers to use the recommended quantity of NPK on its own, they should rather use OFA plus 50% NPK, or 100% OFA.  The same conclusion is likely to apply across the region.

The table also highlights OFA’s efficiency. It weighs less than 1% of the equivalent NPK, which means that transporting OFA to even the most remote farming areas is relatively cheap and easy.

As OFA is organic, it also protects farmer health, and local soils and watercourses.

OFA has a small carbon footprint, and is far better for climate change mitigation and adaptation than NPK. In other trials, OFA was shown to significantly improve crop water use efficiency, assisting climate change adaptation.

As farmers are the direct beneficiaries of OFA’s huge cost effectiveness advantage, they are the main focus of HJA Africa’s work to spread knowledge of its benefits.  But OFA is also fantastic news for Ghana and Africa, as it is an affordable 100% Ghana-made product avoiding costly foreign exchange denominated import bills.

Capacity to supply OFA is not an issue. HJA Africa already has the annual production capacity to treat 3 million acres (over 1 million hectares), more than enough to meet all the fertilizer needs of our current market, Ghana, and will expand production as required.

Turning to the longer-term Africa wide picture, given returns on farmer investment in effective biostimulants like OFA are so high, and they are so affordable, there are strong incentives for farmers to start using OFA or other effective organic biostimulant fertilizers. There are approximately 0.3 billion hectares of cropland in sub-Saharan Africa, so OFA’s returns for farmers of typically $250 extra profit per hectare mean that widespread adoption of OFA and similar fertilizers across Africa could deliver up to $75 billion in additional profit per crop production cycle. That scales up to $150 billion annually if we assume there are typically two crop cycles per year. Applying an economic multiplier of 2 to this income increase gives the final potential economic benefits as up to $300 billion annually.  The benefits could be even higher if, as seems likely, much higher farm profitability also leads to more agricultural land that is currently unused or left for pasture being converted to profitable crop use.

This increased income will be focussed on the relatively poor rural smaller farmers that form more than half of Africa’s working population, and on their neighbours through the multiplier effect, so dramatically reducing income inequality. The crop yield increases would also solve much of Africa’s food security challenge, and there would also be huge environmental benefits. Incidentally, these impacts would also deliver a large part of many of the UN Sustainable Development Goals (SDGs) across Africa.

Of course, there may be many reasons it will not prove possible to achieve this full potential, but delivering even a fraction of the potential economic output gains of up to $300 billion a year (or even more) in sustainable economic activity across Africa would be transformational and incredibly worthwhile.

So what’s stopping us achieving all of these huge benefits immediately by widespread adoption of the organic biostimulant fertilizer technology that underpins OFA’s excellent results?

Well, we have made a promising start. Over the 5 years HJA Africa has been selling OFA to Ghanaian farmers, our tens of thousands of farmer users have given excellent feedback, and demand is growing fast. OFA’s progress is marked by winning 2023 Ghana Agricultural and Agro Processing Awards Ghana-made fertilizer of the year.

Nonetheless, adoption of innovations takes time, particularly when current practice is strongly embedded and supported by governmental, inter-governmental, and non-governmental agencies, and by large private companies, as is the case with NPK.

Importantly, farmers are rightly cautious about using unfamiliar agro-inputs on their precious crops, which often represent most of their capital. They have frequently been disappointed by undelivered promises of good performance in the past.

However, seeing is believing, as our many OFA users can attest. I therefore urge Ghanaian and African farmers, and their advisers, simply to trial OFA for themselves, on its own or in combination with reduced amounts of NPK depending on crop and on soil quality, to confirm its outstanding cost effectiveness in increasing yields for all crops.  We will then soon reach a tipping point of farmer awareness, leading to rapid large-scale take-up. This is what happened with NPK following its effective introduction to many parts of Africa over the last two decades, but could happen much faster in this case because the financial returns are more attractive for farmers.

Of course, other good farming practices should be followed to get good results, in particular use of good seeds, soil care, keeping farms weed-free, timely action to address pest or disease issues, and where possible irrigation. But the evidence is clear that the financial benefits of effective organic biostimulant fertilizers are very large, as well as giving us all big environmental gains.  And indeed, combining such fertilizers with these good farming practices will deliver even larger increases in yield and profit.

By strongly aligning the farmer’s personal financial interest with wider societal interests (both environmental and for food security), OFA‘s technology provides a practical, scalable, market-based solution for Africa’s low crop yields.

This contrasts with some of governments and NGOs strategies for promoting crop yield increases. Firstly, expensive and often ineffective efforts to help farmers who are not credit-worthy to borrow money that puts them at financial risk, in particular to buy costly synthetic fertilizers that deliver limited benefits in sub-Saharan Africa, and can be damaging environmentally including to the farmers own soil. Secondly, providing direct on-going input subsidies for synthetic fertilizers that often get mis-appropriated or mis-directed, distort markets and deter innovation, lock Africa into import dependency and specifically into reliance on other parts of the world for maintaining its food supply, and do not give farmers the predictability needed to help them build strong, sustainable and independent farm businesses for themselves.

Indeed, current plans for a 2024 African Union fertilizer and soil health summit continue some of these mistakes by explicitly targeting increases in the volume of synthetic fertilizer use, rather than what actually matters, which is increasing crop yields and farmer profits sustainably.

It’s high time to try out new evidence-based sustainable approaches like OFA that are already delivering great results for users.

And as more and more farmers join the many already using OFA, (and over time other effective organic biostimulant fertilizers), Africa will leapfrog the so-called Green Revolution to a true Deep Green Revolution, that is sustainable in both financial and environmental terms, and brings huge development benefits to our farmers, to the continent, and to our planet.

The author is CEO of impact-first Ghanaian business HJA Africa, makers of OFA liquid organic fertilizer and  may be contacted at [email protected]

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