Why can excessive tillage increase runoff and reduce water storage in soil?

Excessive tillage can negatively impact soil health in vegetable farming by breaking down the soil's natural structure. When tillage is too intensive, it destroys the stable pores that allow water to infiltrate the ground, often leading to surface crusting.12

This process increases runoff and reduces water storage for several reasons:

• Destruction of Soil Structure: Intensive mechanical manipulation can reduce soil to a single-grain structure, which facilitates surface cementation and impedes water intake.1
• Compaction: Conventional plowing can create a "hardpan" or plow sole—a compacted layer just below the tilled zone—which restricts water movement and storage.23
• Loss of Protective Residues: Unlike no-till agriculture, which uses crop residues to protect the surface and improve infiltration, excessive tillage removes these protective layers, leaving the soil vulnerable to the impact of raindrops that can further damage surface structure.41

By minimizing disturbance, farmers can better maintain soil aggregates and porosity, which are essential for effective water infiltration and long-term moisture retention.241