Confused about soil amendment and fertilizer? How is each different, and what product should you use for your garden? In this guide, we're shedding light on the differences between soil amendment and fertilizer to help you choose the perfect product for your needs.

What is the Difference Between Fertilizer and Soil Amendment

While fertilizer and soil amendment have many similarities, these are two different products. They have different formulas and serve different purposes.

Fertilizer: This product adds nutrients to the soil and improves plant growth. It is not used to enhance soil consistency. It is only used to target specific plant needs and soil nutrient deficiencies.

For example, applying fertilizer in clay soil won't make the texture looser. It will not improve the soil's consistency. Fertilizer is sold with different elemental mixtures, and the ratios in the packaging reflect the formula. 1-1-1 fertilizers, for instance, have a balanced ratio of nitrogen, potassium, and phosphorus.

Soil Amendments: Soil amendments are products added to the soil to improve its texture. The product creates air pockets that will enhance aeration while accelerating root development. Using soil amendments in your garden enables plants to grow strong, healthy roots and foliage. Soil amendments can be organic or inorganic.

One important thing to consider before using any of these products - your soil should have healthy microbial activity. In raw form, some nutrients cannot be absorbed by plants.

Microorganisms in the soil can break down both products and convert them into nutrients that plants can absorb easily. If your soil has healthy microbes, the desired effect will be achieved regardless if you use fertilizer or soil amendments.

6 Types of Soil Amendment Materials to Improve Garden Soil

Soil amendments can be made from organic and inorganic materials. If you want to avoid using soil amendments made from synthetic chemicals, there are great products made from natural materials. Below are the six types of natural soil amendment materials:

Compost: This is a popular soil amendment material derived from decaying organic matter. You can build a compost pit in your backyard and transform kitchen scraps and yard waste into compost. Compost improves soil structure and enhances nutrient availability so plants can absorb nutrients efficiently.

Manure: Animal manure contains high amounts of nitrogen, potassium, and phosphorus, which plants need to grow healthy. Usually, cow, horse, and chicken dung are used as soil amendments. However, animal wastes should be aged or composted before they're applied into the soil to prevent the spread of pathogens.

Leaf Mold: This soil amendment material is made from decayed shade tree leaves. Leaf mold is produced from a cool and slow, fungal-driven process, unlike compost, which is produced from a heat-producing bacterial-driven process. Leaf mold is a rich source of essential nutrients plants need to grow healthy.

Seaweed: Marine plants like kelp are packed with essential nutrients, antioxidants, and minerals that promote better plant health. Applied in soil, seaweed improves soil texture, boosts its water-holding capacity, and makes plants resistant to diseases.

Humic acid: Humic acids are a complex mixture of organic molecules formed from decomposed organic matter. This soil amendment material is rich in minerals essential for plant growth. Applied in soil, humic acid boosts soil fertility, improves water retention, and promotes plant nutrient uptake. Humic acid also supports microbial activity in the ground, which improves soil quality.

Fish meal: This soil amendment material is derived from fish processing byproducts. Fish species like anchovy, herring, and sprat are used to make fishmeal. These fish species contain calcium, phosphorus, magnesium, potassium, and other nutrients that promote healthy plant growth.

Types of Natural and Manufactured Organic Fertilizers

When it comes to commercial fertilizers, these products are available in two types: natural and manufactured. Here is a list of natural and manufactured organic fertilizers:

Natural Fertilizers

Animal manure: Collected cow, horse, and chicken dung is aged or composted before being used as a natural fertilizer. Animal dung is an excellent source of nitrogen, phosphorus, and potassium, which are vital for plant growth.

Compost: Kitchen scraps and yard wastes are composted. Once broken down into crumbly black soil-like materials, it can be used as a natural fertilizer. Compost is prized for its balanced mix of nutrients slowly released into the soil for plants to absorb.

Bone meal: Crushed and finely ground animal bones - typically cattle bones - are a great source of calcium and phosphorus that support root development and improve plant health.

Blood meal: Animal blood in slaughterhouses is collected, dried, and turned into a natural fertilizer. Animal blood is an excellent source of iron, nitrogen, phosphorus, and potassium.

Fish emulsion: Fish waste from whole or parts of fish (bones, scales, skin, guts) are collected and processed into an emulsion, which is applied to the soil to improve fertility. Fish emulsion contains calcium, nitrogen, phosphorus, potassium, and trace minerals that promote better soil and plant health.

Manufactured Organic Fertilizers

Compost tea: This organic fertilizer is made from compost steeped in water. Added to soil, compost tea provides a balanced mix of nutrients to improve soil and plant health. It is also packed with beneficial microbes to improve the garden's health.

Seaweed extract: This soil fertilizer is derived from marine plants, particularly kelp. Aquatic plants are processed and extracted to create a highly concentrated, water-soluble liquid fertilizer. Seaweed extract is an excellent source of essential minerals that improve soil and plant health.

Worm castings: This manufactured organic fertilizer is derived from worm waste or vermicompost. Worm waste is a rich source of nutrients plants need to grow healthy. This natural fertilizer also supports microbial activity in the soil, which boosts the garden's health.

Feather meal: This manufactured organic fertilizer is derived from poultry byproducts, particularly the feathers. Poultry feathers are collected, ground up, and processed as a natural fertilizer. Feather meal is often used to promote leaf development.

Soybean meal: This is a plant-based manufactured fertilizer from soybean seeds. After extracting oil from soybeans, the dried-up remains are grounded and processed into soybean meal. Soybean seeds are an excellent source of potassium, phosphorus, and calcium.

ECOgardener And The Best Way To Improve Your Garden Soil

Going natural and organic is the best way to go if you are amending the garden's soil. As you can see from our list above, many natural and organic soil amendment products and fertilizers can be used to improve soil health and support better plant growth.