In a typical row crop production system, most of the soil organic matter originates from what source?

In a typical row crop production system, the primary source of soil organic matter is crop residues. Crop residues consist of the leftover plant material from harvested crops, such as leaves, stems, and roots. When these residues decompose, they enrich the soil with organic matter, which is essential for maintaining soil health, improving water retention, and enhancing nutrient availability for subsequent crops.

Crop residues play a significant role in building soil structure and promoting microbial activity, both of which are crucial for sustainable agricultural practices. While other sources like cover crops, animal manure, and natural vegetation contribute to soil organic matter as well, the consistent and substantial input from crop residues, particularly in row crop systems, makes them the most significant source in this context. This input is especially important in systems where multiple crops are grown in rotation, leading to continuous addition of organic matter.