Why Use Organic Fertilizers?

The big divide in the world of fertilizers is between synthetic and organic. Each type has different uses and characteristics, but which is the right choice for your garden in the Pacific Northwest?

What’s the difference?

Generally, synthetic fertilizers are just that: processed compounds of specific chemicals, such as nitrogen, that can boost plant growth. They offer an easily absorbable infusion of nutrients for plants.

Organic fertilizers are a bit more complex. They are natural substances that contain high levels of the nutrients plants need. As they break down, they release those nutrients into the soil.

What are organic fertilizers made from?

Many organic fertilizers may sound familiar. Some, like manure and bone meal, have been used for hundreds of years to fertilize crops.

Compost is the most common one you may have heard of, but urine, blood meal, kelp and types of stone are all organic ways to adjust soil composition to be more favorable to plant growth. Oregon State University has more information here.

What does my soil need?

That depends on your soil composition and the plants. To find out more, you can send in a sample of your soil for testing.

Based on the testing results, you can then select a natural or synthetic fertilizer that will provide the elements your garden is lacking and bring the soil back in to balance. OSU also has more information on that process here. Washington State University maintains a list of labs in Washington that provide soil testing.

What do the numbers on fertilizer or soil tests mean?

The main things soil testing measures are nitrogen, potassium, calcium, magnesium and phosphorus.  Correcting deficiencies of these requires targeting the area with specific fertilizers.

Nitrogen, phosphorous and potassium are the “big three” usually targeted by fertilizers. They are often referred to as N, P and K, respectively. For example, you may see a bag of fertilizer with an N-P-K ratio of 4-6-3 on it, indicating what percentage it is of each nutrient.

According to OSU, urine is nitrogen rich, while bone meal or rock phosphate provide more phosphorous. For potassium, kelp and wood ash are both options.

Soil testing also measures the PH value of your soil: how acidic it is. You can use natural items such as shellfish shells to lower the acidity of the soil.

Synthetic vs organic

You can think of the difference between synthetic and organic fertilizer in terms of nutrition. Synthetic fertilizer is like a highly processed candy bar that your body can easily absorb for a quick boost of energy. Organic fertilizer is like a more complex vegetable that takes longer for your body break down over time, providing a more sustainable source of energy.

Just as it’s healthier for your body to eat vegetables than a candy bar, organic fertilizers offer long-term benefits to soil health. By slowly releasing nutrients they help bring the soil in to balance. The spike in nutrients provided by synthetic fertilizer is unsustainable and requires repeated re-application.

Other reasons to go organic

Organic fertilizers are more sustainable in other ways as well. Ammonia fertilizer, the most common kind of synthetic fertilizer, contributes as much as two percent of global CO2 emissions. Unabsorbed nitrogen from fertilizer can enter the atmosphere or run off into local waterways, causing serious environmental damage.

Conversely, organic fertilizer is less harmful to the environment and plants in concentrated amounts, and actually can help prevent run off from occurring at all. It does this by helping build healthier and more structured soil as it breaks down, leaving your garden better than it was before.

Our preference

At Pacifica we like to use compost. The soils in the Puget Sound area are usually sand and gravel that may be somewhat acidic due to the leaching effects of the rain and the acidity from decaying coniferous plant materials. Compost can provide the organic material needed to help maintain soil moisture levels, provided habitats for the microorganisms essential to soil health, and provide an accessible form of nitrogen, phosphorous and potassium, which are the primary nutrients for plants.