- Depending on the type of organic fertilizer used, it can be more expensive than synthetic fertilizers.
- Available bag sizes aren’t large or economical enough for homeowners.
- Synthetic fertilizers are most commonly used, readily available, available in greater amounts, and generally, cost effective.
- Controlled-release pellets are more expensive.
- Some organic fertilizers are in their “raw” form, not pellets, and may take extra effort to distribute over large areas.
- Generally, no harm will result from over application or spills.
- Use a fertilizer spreader according to manufacturer rates.
- Accidental over application, including overlapping rows when fertilizing, can cause lawns to burn.
- Natural-based fertilizer nutrients can fluctuate.
- Micronutrients are typically present, providing some of the trace nutrients plants require.
- Nutrient amounts are highly accurate.
- Blends can be formulated for specific needs.
- High nutrient concentrations may build-up in the soil, which may lead to leaching and run-off.
- Generally, don’t contain necessary micronutrients.
- If it contains water-soluble iron, it can stain concrete.
- Nutrients are released at a rate plants can use, greatly reducing the chance of leaching or run-off.
- Microbes in the soil break down the organic material releasing the nutrients.
- Requires fewer applications, which means less work over time.
- Controlled growth that doesn’t over-stimulate plants, promotes stronger root growth for better disease and insect resistance.
- Reliant on soil temperature: cooler soil = slower release rate, which corresponds to the rate plants can take up nutrients.
- Poor quality soils depleted of beneficial microbes may delay results.
- Long lasting.
- Synthetic fertilizers give lawns and gardens a quick, but short-lived, burst of nutrients, which can cause rapid growth at the expense of developing a strong root system.
- May see results in 1–2 weeks.
- More mowing will be required due to rapid growth.
- Water soluble in most forms.
- Because nutrients are released quickly more applications will be required.
- Many forms available: pellets, granules, liquid, tablets, spikes, and controlled-release.
- Short-term solution to a long-term need.
- Promotes a healthy soil ecosystem.
- Provides organic material that decomposes, releases nutrients plants can use and feeds vital microorganisms, all important for rich, fertile soil.
- Improves soil texture, which increases water retention, particularly important in drought conditions.
- Synthetic fertilizers contribute very little to the ecosystem or structure of the soil.
- May actually decrease soil fertility due to chemical nitrogen stimulating excessive microorganism growth, which, over time, depletes organic matter in the soil.
- In most cases, won’t burn plant leaves or roots.
- Manure should be composted for greatest safety.
- Incorrect or over application may burn plants due to high concentrations of chemical nutrients, which are salts.
- Can cause excess top growth and stress roots.
- Minimal, if any, run-off or leaching.
- Since water releases nutrients, a significant amount of nutrients can be lost from run-off and leaching, sometimes up to one-third.
