When an area is deforested, the area becomes subject to soil erosion, where the soil is easily washed away. What’s more, most of the agricultural plants that replace the trees, such as coffee and soybean, cannot hold on to the soil.
Overgrazing in a deforested area also reduces the ground cover, enabling the soft topsoil underneath to be eroded and also causes the land to become more compact. This affects the plant’s ability to penetrate the ground with its roots and the water’s ability to enter the soil.
The overuse of chemicals such as pesticide can kill the microorganisms in the soil that make it fertile and result in the growth of harmful bacteria that affect the good microorganisms.
After all the fertile soil has eroded, farmers simply move to another area to deforest and the cycle continues. The barren land that remains is then more prone to flooding.