Soil is the greatest resource on Earth and the farmer’s best companion. It is the most diverse component, harboring millions and billions of micro- and macro-life forms. It offers the very fundamental support system to every other life form above ground. To the farming community, time and investment in the companionship can either make or break hearts over time.
Smallholder farmers mainly rely on soils to produce and earn a living. It is henceforth only fundamentally appropriate to feed the soils to have a similar level of surety that they will support your economic and other functional needs prospectively. How then do we feed our soils? This is the question that continues to drive research in the disciplines of soil science and plant ecology. At the very basic level, we can consider feeding the soil as supplying it with the necessary resources to ensure it sustainably maintains a thriving community of biodiversity and natural resources with net positive economic and ecological functions. At the farmer level, it goes above and beyond.
A couple of decades back, our grandparents and great-grandparents cultivated the very same fields we cultivate today but with zero supplements as mineral fertilizers. If any, animal manure was applied suboptimally, and yet the productivity was way above what we collect today. Currently, we either have to apply a sufficient amount of animal manure or mineral fertilizer to reap even half what our grandfathers and great-grandfathers produced on the same farms. We can admire how privileged it must have felt to produce abundantly under such limited resource use but also assertively strategize to overcome the threat of glaring hunger we face today.
Mineral fertilizers have been frequently associated with deleterious side effects of soil acidification, waterway pollution, and emission of nitrous oxides. However, mineral fertilizer has also been the most significant contributor to global food security and is currently sustaining half the world’s population. In Africa, the fruits of efficient utilization of these resources continue to elude smallholder farmers. Yield output in the majority of farms remains at only 25% of potential productivity. Many farmers fail to adopt good fertilizer use practices by applying significantly low quantities of fertilizer, using inappropriate fertilizer application techniques, and failing to match crop nutritional needs with the correct type of fertilizer.
The idea that inorganic fertilizers destroy farms has been widespread among many smallholder farmers. Is it true or false? It is in our experienced view that either case can be true, but only when considered in the context of select use cases. Generally, though, what has been inferred as widespread destruction is majorly attributable to inappropriate fertilizer use practices. For instance, the National Agriculture Soil Fertility Management Policy of 2020
of Kenya identifies low application rates of fertilizers among the most significant obstacles to the attainment of food security. This situation has been reiterated across many African countries. In fact, only Egypt and Mauritius have exhibited generous application of mineral fertilizers in recent years at approximately 414 kg/hac and 177 kg/hac. No other country surpassed 100 kg/ha. The continental use averaged 25.6 kg/hac, almost five times less than the global average of 118.6 kg/hac (FAO, 2023). At such rates, the amount available to crops can barely sustain their basic nutritional needs. This henceforth compels the crop to ‘dig’ into the soil’s reservoir and mine for minerals to supplement the deficit. Over time, we end up with significantly deteriorated soils whose fertility cannot support any viable food production.
Yes, when applied in excess and in inappropriate forms, fertilizers leach through the soil and cause acidification or algae bloom in large water bodies, with all sorts of problems for aquatic life. Sometimes significantly low rates are applied, yet with similar deleterious effects. For instance, many farmers are fond of broadcasting top-dress fertilizers in farms with poor drainage, resulting in the carriage of all fertilizers through surface runoff into nearby streams.
The question then begs significant deliberation: Do we use more fertilizers and attain food security or join the global initiative of advocating for a reduction in emissions of nitrous oxide, a highly potent greenhouse gas? Scaling accelerated adoption of green alternatives like the use of organic fertilizers offers a more optimistic solution to our quagmire. However promising, the practical transition to such alternatives portends significant financial implications individually for farmers and nationally for state departments of agriculture. Not to mention, Africa is still substantially using low levels of mineral fertilizers and will need to increase her fertilizer consumption and eliminate chronic hunger before it even attempts to convince her farmers to abolish a highly nutrient-efficient, cost-effective solution for a more costly alternative.
Several countries have already rolled out fertilizer subsidy programs to incentivize more farmers to increase fertilizer usage. However, more needs to be done in accelerating adoption. Such overarching beliefs, such as that fertilizers destroy farms, can only be negated through inclusive transformative capacity-building initiatives that are more social, cultural, economic, and gender-responsive. Considering that increasing the rates of fertilizer use also increases production costs for individual farmers, changemakers must ensure that proposed thresholds are positively reflected in yield. One way to ensure this is by availing of cheaper, highly reliable, and fast soil testing services at the farm gate. This will ensure that proposals to increase application rates are contextualized to specific farm and crop needs. In addition, it will avoid deleterious use of fertilizers and provide a baseline to which productivity, financial, and ecological change can be tracked. This will offer a unique opportunity for informed remedial interventions with a high impact on return on investment and national returns.