Your garden soil needs fertiliser to provide your flowers, shrubs and vegetables with the nutrient levels necessary to foster productive growth. When you're walking down the aisles of your garden store, you can either choose fertilisers made from organic material, such as composted animal manure, or synthetic, artificial fertilisers sold in powder, granular or liquid form. The latter kind of fertiliser offers several distinct pros and cons that you should consider before making your final choice.
Advantage: Faster Nutrient Release
Unless you buy a synthetic, artificial fertiliser specifically formulated as a slow-releasing formula, artificial fertilisers generally make their nutrients available to your plants immediately. This gives your garden an immediate nutrient boost. In contrast, fertilisers made from organic matter release their nutrients more slowly via the process of decomposing and bacteria growth, which thus requires more advanced planning and proper application timing.
Advantage: Precise Nutrient Dosages
Synthetic fertilisers are very precise when it comes to nutrient levels. They often come labelled with their specific nutrient content, plus how much fertiliser you need to apply to obtain a specific result. In contrast, organic fertilisers, such as manure or compost, have varying levels of nutrients and it can be much harder to determine how much fertiliser you need to apply.
Disadvantage: Constant Application Needed
While their quick-releasing action means synthetic fertilisers offer up their nutrients quickly, it also means that these nutrients quickly dissipate. This requires constant applications throughout the growing season to maintain soil nutrient levels. In contrast, natural, organic fertilisers release their nutrients slowly over time and don't need to be replenished as often.
Disadvantage: Environmental Pollution
Irrigation or rainfall can leech artificial fertilisers' nutrients, specifically high levels of nitrogen, away from their direct application spot. This excess nitrogen can then end up in nearby waterways and groundwater. This can cause various forms of environmental pollution and side effects, including fish kills in rivers and algae blooms in lakes.
Disadvantage: Plant Toxicity
Because synthetic fertilisers have higher levels of quick-releasing nitrogen, it can be easier to accidentally overdose your soil with nitrogen. This can result in chemical burns to your plants' roots and green tissue.
- Virginia Cooperative Extension; Fertilizing the Vegetable Garden; Diane Relf, et al.; May 2009
- Earthbound Farm: Organic Farming 101
- Oregon State University Extension; Here's the Scoop on Chemical and Organic Fertilizers; Carol Savonen
- "Pollution Prevention Review'; Nitrogen on the Land: Overcoming the Worries; Charles Frink, et al.; Summer 2001
- University of Saskatchewan Extension; Fertilizer: Application; Sara Williams