Do I Need to Use Compost With Fertilizer?

What is Compost?

• Compost is decomposed organic material. Lawn clippings, plant matter, livestock waste and kitchen waste such as vegetable and fruit peels and wilted greens combine with water, oxygen and microorganisms. The mixture decomposes over time, resulting in a nutrient-rich pile that resembles soil. Compost is dark and crumbly with an earthy smell.

Advantages and Disadvantages of Using Compost

• Compost adds organic, meaning carbon-based, material into the soil, which improves both water retention and drainage. Compost also tends to be nitrogen-heavy. Nitrogen is one the most important nutrients for plant growth. However, unless the waste products used to make the compost were carefully monitored and measured, it is difficult to know the exact amount of nutrients in compost. Also, composting does not kill seeds or plant diseases. If weed seeds or diseased plants were used to make the compost, the seeds and disease will be in the soil.

What is Fertilizer?

• Synthesized or chemical fertilizers are chemical compounds created to release a specific amount of plant nutrients into the soil for plants to take up through their roots. Organic fertilizers are soil additives that come from natural sources such as bat guano. Most commercial fertilizers, whether chemical or organic, are labeled according to how much nitrogen, phosphorus and potassium they contain.

Advantages and Disadvantages of Using Fertilizer

• Fertilizers apply a specific amount of nutrients to the soil. A 16-4-8 fertilizer is 16-percent nitrogen, 4-percent phosphorus and 8-percent potassium. Knowing the exact nutrients in the fertilizer allows you to choose exactly what your plants need. However, overuse or misuse of chemical fertilizers can harm your plants and your local water supply. Also, fertilizer alone will not help soil that lacks organic material.

The Two Together

• Although compost contains nutrients, its biggest benefit is how it improves the soil's overall make-up and texture. Fertilizers add nutrients but do nothing for improving the soil's characteristics. Using both compost and fertilizer together improves the soil's ability to retain water, improves aeration in the soil and provides proper nutrients to the plants for a beautiful garden.