More Crops

• Because fertilizer contains many of the substances plants need to grow, this can help produce more crops. At an industrial level, this means a more profitable yield of crops like potatoes and apples per square mile, while for home gardeners it simply means a more reliable, bigger haul of fruit and vegetables. Flowers such as roses may experience longer-lasting blooms when fertilized early with horse manure. Slow-release granular fertilizer also offers nutrients for the plant over a long period before it seeps into the soil.
  
  

Nutrient Replacement

• Some areas contain poorer-quality soil than others. Sandy soil, for example, might not have too much organic material on which plants can feed. Fertilizer enables gardeners to add or replace nutrients in the soil where necessary. Horse manure and compost added to sandy soil increase the amount of nutrients and help the soil retain more moisture instead of draining too fast. Low-nutrient soil may require regular enhancement with chemical fertilizer to make it suitable for plant growth.
  
  

Organic Benefits

• Compost and organic fertilizer contain a greater range of nutrients than most artificial fertilizers, according to the Washington State University Extension. Organic manure and rotted material tend to release these nutrients over a long period, meaning you can improve the overall quality of your soil for years. Using organic material can also help bring alkaline or acidic soils to a more neutral pH that suits a greater range of plants.
  
  

Inorganic Fertilizer

• Inorganic fertilizers are usually found in liquid or pellet forms and are easy to apply. You can also use chemical fertilizers to add specific nutrients. For example, if your soil is low in potassium, you can include phosphorus fertilizer. General inorganic fertilizer contains three of the main substances required for healthy plants--potassium, nitrogen and phosphorus. This type of fertilizer offers plants easy-to-use food, making it useful if you need to quickly feed a failing plant or give your plants a growth boost.