Synthetic fertilizers are made from chemically processed substances. The nutrients they release are immediately available to plants without having to be broken down by biological activity in the soil. This means that they nourish plants but do not improve soil fertility in the longer term.
A wide variety of chemical fertilizers is available. They come in tablet, granular, stick, powder and liquid form. Most of these fertilizers are fast-acting, but some slow-release formulas are also available. It is better to use slow-release formulas because there is less risk of leaching and of burning plants’ roots.