What is an effect of high soil organic matter content on water movement?

High soil organic matter content is known to significantly improve the physical properties of the soil, particularly in relation to water movement. One of the primary benefits of increased organic matter is its ability to enhance soil structure, which in turn increases the soil's capacity to retain moisture and allows for better infiltration rates.

While it's true that high organic matter can help retain water and may initially lead to a slight slowing down of water movement due to its enhanced structural properties, the overall effect is generally an increase in infiltration and improved drainage. Organic matter helps to create pore spaces that facilitate the movement of water through the soil profile. It also supports biological activity which further contributes to soil aeration and the breakdown of soil aggregates, enhancing the soil's overall water handling characteristics.

With this understanding, it is clear that the correct choice should reflect the impact of organic matter on water infiltration, rather than suggesting that it would universally slow down water movement in a detrimental way. While certain contexts might show a temporary slowing due to the complex interactions of water retention and infiltration capabilities, the prevailing effect of healthy organic matter levels is to support and enhance overall water movement through soils.