What is crop residue primarily made up of?

Crop residue is primarily composed of leftover plant material that remains in the field after the harvest of crops. This material includes stalks, leaves, and other parts of the plants that are not collected for sale. One of the key benefits of crop residue is that it contributes organic matter and nutrients back into the soil as it decomposes. Specifically, nitrogen is one of the macronutrients that can be enriched in the soil by breaking down this plant material.

As crop residues decompose, they enhance soil structure, improve soil moisture retention, and foster a diverse ecosystem of microorganisms that can further support soil fertility. This process is crucial for sustainable agricultural practices, as it helps maintain soil health and productivity.

The other options do not accurately describe the primary components or functions of crop residue. Grains harvested for sale are intended for consumption and do not contribute back to the soil once removed. Waste from livestock feed refers to animal by-products rather than plant material leftovers. Decaying roots and soil amendments relate to soil health but do not specifically fit the definition of crop residue itself.