For decades, converting wetlands into farmland has seemed like a practical way to produce more food. Drain the water, prepare the soil and turn the land into fields for crops.

But new research suggests that this strategy may come at a much greater cost than previously understood.

A global study published in Nature Sustainability on 9 October 2026 has found that nearly half of the croplands developed on former wetlands produce lower yields than existing farmland. Even more concerning, many of these converted areas face unusually high flood risks.

Researchers from the Chinese Academy of Sciences and international institutions examined how wetland conversion has affected food production and flood exposure across the world. The findings received renewed attention in research reporting released on 16 October.

Their conclusion challenges a long-standing assumption: turning more natural land into farmland does not necessarily mean producing more food.

Why Are Wetlands Being Converted Into Farmland?

Wetlands include marshes, swamps, floodplains and other areas where water shapes the soil and surrounding ecosystems.

They support fish, birds, plants and countless microorganisms. They also help regulate water flows, store carbon and maintain biodiversity.

Despite these benefits, agricultural expansion has transformed many wetlands into cropland.

As populations grow and food demand increases, governments and farmers often look for additional land to cultivate.

Wetlands can appear attractive because they may contain nutrient-rich soils and have access to water.

However, converting them into farmland generally requires drainage systems, changes to natural water flows and sometimes extensive land modification.

Those interventions can permanently change how the surrounding ecosystem functions.

The new study examines whether the additional agricultural production actually justifies these changes.

Researchers Examined More Than Two Decades of Land Conversion

The research team, led by Professor Jinwei Dong from the Chinese Academy of Sciences, mapped agricultural areas that replaced wetlands between 2000 and 2022.

They then compared crop productivity and flood exposure across those areas.

The results were surprising.

Nearly half of the converted croplands produced lower yields than established agricultural land.

These newly cultivated areas contributed only 0.1% of total global crop production.

In most regions examined, their contribution to agricultural output remained relatively small.

That raises an important question.

If converting wetlands produces so little additional food, is losing the original ecosystem worth the cost?

The Flood Risk Was Even More Concerning

The researchers discovered that 52% of croplands created from former wetlands lie in areas exposed to significant flood hazards.

These areas cover approximately 21,001 square kilometres.

The study also found that the average probability of flood exposure was 23 times higher than that of croplands overall.

This is a particularly important finding because wetlands naturally absorb and temporarily store large quantities of water.

During heavy rainfall, they can slow runoff and help reduce flooding in surrounding areas.

When people drain or convert wetlands, they can weaken those natural functions.

The result may be farmland that produces limited additional food while remaining highly vulnerable to the same water conditions that originally supported the wetland ecosystem.

A Problem That Affects Agriculture and Nature

The researchers identified another troubling pattern.

Approximately 60% of wetland-reclaimed croplands experienced both limited agricultural gains and high flood exposure.

The study describes this combination as a situation where agricultural development and environmental protection both lose.

The researchers found major concentrations of these areas in East and South Asia, North America, eastern South America and Oceania.

China, the United States and India together accounted for approximately 34% of the identified trade-off hotspots.

The findings are particularly relevant for countries where food security remains a major concern.

Agricultural land that produces unreliable yields and faces repeated flooding can create additional financial risks for farmers.

That makes wetland conversion not only an environmental issue but also an economic one.

Wetlands Provide More Than Wildlife Habitat

One reason wetlands often lose out to development is that their benefits are not always immediately visible.

A farmer can measure how much rice or wheat a field produces.

It is more difficult to calculate the value of floodwater absorbed by a wetland during a storm.

Yet this natural service can protect nearby farms, homes, infrastructure and communities.

Wetlands also filter pollutants, support fish populations, store carbon and provide essential habitat for migratory birds.

Removing them can weaken several environmental systems at once.

The new research highlights why land-use decisions should consider these wider benefits instead of measuring success only by the amount of land brought under cultivation.

Does This Mean Wetlands Should Never Be Used for Agriculture?

The findings do not suggest that every wetland conversion project produces the same outcome.

Agricultural productivity depends on local soil conditions, climate, water management and crop selection.

Some converted areas may produce useful agricultural output.

However, the study demonstrates that widespread wetland conversion is not automatically an effective food-security strategy.

Researchers also relied on global mapping and comparative analysis, meaning the findings describe broad patterns rather than the exact economic or ecological outcome of every individual farm.

Governments therefore need to evaluate local conditions carefully before expanding agriculture into wetland ecosystems.

A Better Approach to Food Security

Instead of continually converting natural habitats into farmland, countries could focus more strongly on improving the productivity and resilience of existing agricultural land.

Better irrigation, soil management, crop selection and reduced post-harvest losses can help increase food availability without requiring extensive land conversion.

Wetland restoration could also help reduce flood exposure and strengthen the surrounding landscape.

For farmers operating near rivers and floodplains, maintaining healthy wetlands may provide a form of natural protection that conventional infrastructure cannot always replace.

The important shift is recognising that agricultural development and ecosystem conservation do not necessarily have to compete.

In some landscapes, protecting nature may actually help protect food production.

What Comes Next?

The study provides new global evidence that policymakers can use when making decisions about agricultural expansion and wetland conservation.

Future research could help identify where wetland restoration would deliver the greatest benefits and where existing converted farmland faces unacceptable flood risks.

Governments will also need to balance conservation priorities with the livelihoods of farmers already using these areas.

Restoration cannot succeed if it ignores local communities, land rights or food-security needs.

But the findings suggest that continuing to drain wetlands simply to increase agricultural land may create more problems than it solves.

Key Takeaway

The world needs to produce enough food for a growing population, but expanding farmland into natural ecosystems does not always deliver the expected benefits.

The latest research shows that many croplands developed on former wetlands contribute relatively little additional food while facing much greater flood exposure.

The lesson reaches beyond wetland conservation.

Sustainable agriculture is not simply about finding more land to cultivate. It is about using land wisely while protecting the natural systems that make food production possible.