Which of the following is a best management practice (BMP) for maintaining and improving organic matter in soil?

The correct choice regarding best management practices (BMPs) for maintaining and improving organic matter in soil is related to the importance of proper pH. Maintaining the appropriate soil pH is crucial because it influences nutrient availability, microbial activity, and plant growth, which are all vital components of healthy soil with adequate organic matter levels. When soil pH is within the optimal range for specific crops, it enhances the decomposition of organic material by soil organisms, leading to an increase in soil organic matter as plant residues and other organic materials are broken down effectively.

In contrast, increasing tillage can lead to soil degradation and loss of organic matter due to the disruption of soil structure and the exposure of organic materials to oxidation and decomposition. Using synthetic fertilizers tends to feed plants directly rather than promoting the natural processes that build organic matter in the soil, and it may not address the underlying soil health. Harvesting existing crop residue might seem to remove organic matter, although some practices do incorporate residues back into the soil. However, simply removing them can decrease organic matter content over time, which is not a sustainable approach for soil health.

Therefore, focusing on proper pH management is a significant step in fostering an environment conducive to organic matter preservation and enhancement in soils.