What effect does harvesting crops have on soil organic matter?

Harvesting crops primarily results in the removal of biomass from the field, which directly impacts the organic matter content in the soil. When crops are harvested, the plant materials, including their roots, stems, and leaves, that would typically decompose and contribute to the soil organic matter are removed. This process decreases the overall input of organic materials, resulting in less organic matter returning to the soil.

Soil organic matter is crucial for maintaining soil health, as it contributes to nutrient retention, soil structure, and moisture-holding capacity. The reduction of organic matter can lead to diminished soil fertility over time and may affect other ecological aspects, such as microbial activity and soil structure.

In contrast, other options do not accurately reflect the impact of harvesting crops on soil organic matter. While some practices, such as cover cropping or conservation tillage, can help to mitigate losses, the act of harvesting alone, without these interventions, typically leads to a decrease in organic matter contributions to the soil.