Which type of turf fertilizer includes both synthetic and natural sources?

The correct choice is organic fertilizers, as they encompass a variety of substances derived from both natural and synthetic sources. Organic fertilizers can be composed of naturally occurring materials such as compost, manure, or bone meal, but they can also include processed materials that have been synthesized to mimic organic effects, which is where the synthetic aspect comes into play. This combination allows for a broader nutrient profile and enhanced soil health, as these fertilizers not only feed the grass but also improve soil structure and microbial activity.

On the other hand, inorganic fertilizers are primarily made from synthetic chemicals that provide nutrients in a readily available form for plants but do not include any natural sources. Natural organic fertilizers focus only on unprocessed natural sources without any synthetic components. Synthetic fertilizers consist solely of chemically manufactured nutrients and lack any organic material, which does not contribute to the soil's overall health in the same way that organic fertilizers can. Therefore, organic fertilizers stand out for their blend of both organic and synthetic elements, making them suitable for sustainable landscape practices.