Right crop, right place

02/07/2026

The difference between a successful harvest and a disappointing one is not always visible from the surface.

In Zambia's Southern Province, maize grown under identical climate conditions and farming practices was found to be unsuitable on one soil type and highly suitable on another. Nothing above ground had changed. The difference lay beneath the farmers' feet.

This pilot assessment illustrates a challenge that extends far beyond Zambia. Around the world, farmers make decisions about what to plant, how much fertiliser to apply and where to invest scarce resources. Yet, the soils that support those decisions can vary dramatically across short distances. Two fields may receive the same rainfall and the same management, while producing very different results.

Understanding these differences is becoming increasingly important as countries seek to increase productivity while making more efficient use of limited resources.

Recent fertiliser supply disruptions and rising input costs have further highlighted the need for more targeted agricultural decisions. When fertilisers are expensive or scarce, knowing which crops are best suited to local conditions becomes even more important for improving productivity and avoiding wasted investments.

For much of modern agriculture, decisions have been guided by climate, seed varieties, management practices and fertiliser recommendations. Soil information has often been harder to obtain, harder to interpret and less readily available to those making decisions on the ground. Advances in soil mapping and crop suitability analysis are beginning to change that, making it possible to transform soil data into soil intelligence that can help farmers, advisers and policymakers make better-informed decisions about crop selection and land management.

By combining information on soils, climate, terrain and crop requirements, researchers can assess which crops are likely to perform well in specific locations and identify factors that may limit productivity. The resulting suitability assessments help indicate where a crop is likely to thrive, where production may be constrained and where alternative crop choices may offer better opportunities. Such assessments provide a clearer picture of agricultural potential before resources are committed to farming.

These insights are increasingly being generated through initiatives such as the Soil Mapping for Resilient Agrifood Systems (SoilFER) programme, an initiative of the Food and Agriculture Organization of the United Nations (FAO) implemented with the financial support of the Government of the United States of America and the Government of Japan. Drawing on soil information, environmental data and crop suitability modelling, the programme supports efforts to better understand soil fertility and land suitability, thus guide management decisions and practices across different landscapes.

One of the tools developed through this work is the SoilFER CropSuit App, which allows users to explore how different crops perform under specific soil, climate and management conditions.

Using this app in Zambia’s Southern Province, analysts examined how maize would fare under rainfed, low-input conditions where multiple soil types occur within the same area. Leptosols, for example, according to the World Reference Base for Soil Resources, are generally shallow, stony soils that can restrict crop growth, while Luvisols are often more fertile soils with greater agricultural potential.

When Leptosols were identified as the dominant soil, maize was classified as not suitable. When the assessment was repeated using Luvisols at the same location, maize suitability increased to very high, together with a substantial increase in attainable yield.

The comparison suggests that soil characteristics alone can have a profound influence on agricultural outcomes. So while a decision may appear sound when viewed through the lens of climate alone, it looks very different once soil conditions are taken into account.

The analysis in Zambia also identified alternative crops that may perform well under the same conditions. Cassava, cowpea and fonio emerged as highly suitable options in the Luvisol scenario, highlighting opportunities for diversification and adaptation.

The potential value of such information extends beyond a single assessment. In Zambia, where improving productivity and strengthening climate resilience are national priorities, tools that help match crops to local conditions can support more informed agricultural decisions.

"The CropSuit App offers accessible, science-based crop suitability information that will help farmers, extension officers, researchers and planners make smarter decisions – from choosing the right crops for local agroecological conditions to managing soil fertility and diversifying crop production," says Rodgers Kabiti of the Zambia Agriculture Research Institute (ZARI) and National Focal Point for the SoilFER Project.

"This tool has strong potential to support Zambia's agricultural transformation by reducing crop failure risks and promoting more sustainable land use."

"By integrating soil, climate, terrain and crop information into a single platform, we created a system that helps users understand local constraints and identify suitable crops for specific locations," says Rutendo Mukaratirwa, FAO Agro-Ecological Zoning Specialist and one of the developers of the CropSuit App.

The application has also been designed with flexibility in mind, allowing it to be further tailored and contextualised to country-specific needs, priorities and agricultural conditions as it is adopted and refined over time.

The lesson from Zambia is straightforward. Before questions about fertiliser, irrigation or seed varieties can be answered, there is another question that comes first: is this the right crop for this soil?

The answer may determine far more than farmers once realised.