How does desertification affect crop yields on rain-fed farmland?

Desertification significantly reduces the biological productivity of rain-fed farmland, leading to decreased crop yields and, in severe cases, total crop failure. Because these lands rely on limited and variable rainfall—typically less than 60 cm annually—they are highly susceptible to the impacts of drought, which can persist for years or decades.12

The decline in yields is driven by several interconnected factors:

• Soil Degradation and Erosion: Rain-fed croplands often utilize annuals, which leave the soil exposed between planting seasons. This vulnerability allows wind and torrential rains to strip away nutrient-rich topsoil.1
• Nutrient Depletion: Heavy downpours can wash away essential nutrients from bare ground, further reducing the land's ability to support healthy crops.1
• Environmental Stress: The loss of perennial plant cover, which typically binds soil with deep roots, exacerbates erosion and reduces the land's resilience.12
• Physical Intrusion: Desertification can lead to increased sand dune encroachment onto active croplands, physically rendering them unusable.2

These processes collectively undermine the long-term viability of agriculture in dryland ecosystems.23