Fertilizer & NutritionSoils & Grow Mediums

How to Use Amendments for Soil Management Practices

The growing season is half over and the beauty of your garden reflects all the hard work you have put into it; all the planning and planting plus the weed pulling and back aching. But the bell pepper near the back of the garden has produced next to nothing and has only a few flowers in bloom. With a slight feeling of defeat, you decide to go to your local garden supply center and purchase a liquid nutrient supplement that is high in phosphorus and low in nitrogen. You return home, use the fertilizer according to the application rates listed on the bottle and then you declare victory! But is this truly a victory, or is it just compensating for something that your soil is lacking?

By using thoughtful soil management practices, a gardener can greatly reduce the need for supplemental nutrient assistance in a safe and natural way. Some liquid nutrient applications, though fast acting, can have unintended and even ill effects on the soil. Liquid fertilizers can leave behind small amounts of nutrients and elements in the soil that cannot be absorbed by the plants. Through time these elements can build up and destroy the bacterial / microbial balance of the soil.

However, this can be avoided by creating a nutrient and microbial rich soil that can support the plant through all stages of its life. By adding various amendments (many of which are organic), you can help preserve the natural health of your soil while, at the same time, increasing your yields. Soil amendments are usually added for 1 of 2 reasons. One is to improve the ‘tilth’ (drainage, consistency, etc.) and the other is for fertilization. Sometimes applying a material intended to improve ‘tilth’ can affect fertilization and vice versa. Fortunately, there are amendments that improve the fertility of the soil.

Earthworm Castings

Castings are possibly the best organic soil amendment available today. They are a microbial rich naturally fine form of humus which is always a part of good soils. Humus is organic matter that has been broken down molecularly making the nutrients readily available to the plant’s roots. In this case items like grass clippings and food waste move through the worm’s digestive system and are broken down. Most earthworm castings have an NPK of 1-0-0 and many have small amounts of calcium and magnesium along with other trace elements. However, what makes earthworm casting stand out is the fact that the form the nutrients are in is one that is easily up taken by the plant. In turn this makes the fertilizer longer lasting with less waste because the plant will only use it when it is needed. Another benefit of using earthworm casting is the fact that there are almost always tiny baby worms that are nearly invisible that will grow up in your soil and continue working long after your initial application. Read this article and learn how to start a worm farm that produces castings for your garden.

Kelp Meal

Kelp meal is a dried seaweed product that is rich in minerals and essential nutrients. Most kelp meal is harvested from the cold waters of the North Atlantic and is organic as well as renewable. Kelp meal also acts as an excellent bio-activator. This means that when added to the soil it will help to break down other organic materials quickly so that the nutrients that they possess can be easily utilized by the plant. Many people add kelp meal to their home compost piles to assist in the decomposition of grass clippings, leaves, and kitchen waste.

Bone Meal

As the name implies, bone meal is made from the bones of many kinds of animals. The bones are ground up, steamed at high heat, and dried. Now that’s what I call using the whole animal! Once again, the importance of a humus rich soil comes into play. The bone meal is broken down on a molecular level by bacteria in the humus. Bone meal is an excellent source of organic calcium and phosphorus which will encourage more blooms and a better fruit set. It has also been found to help mend soils with heavy metal contamination (Mark Hodson & Eva Valsami – Jones 1999).


Compost works wonders to rejuvenate your soil and give it new life. Good compost is rich in beneficial micro-organisms that work to break down organic materials in the soil. When the organic material breaks down completely it becomes humus, which is great for fertility and the suppression of disease in the soil. There are many different kinds of compost, and some can be made at home including manure, mushroom, leaf and lawn clippings. Compost can even be made with the fruit and vegetable scraps from your kitchen. Different types of composts can be mixed and with other soil amendments without worry.

Plants are genetically designed to complete their growth cycles. The only thing you need to do is provide any assistance that the plants may need in a healthy way. When you take great care in managing every aspect of your garden thoughtfully you will be rewarded in many ways. It can help you save money on food and, simultaneously, find some peace of mind in knowing how your food was grown.

Kyle L. Ladenburger is an avid indoor and outdoor gardener.

Related Articles & Free Email Newsletter Sign Up

Composting and Its Unintended Consequences

How Recycling Eggshells Can Help Your Garden

Mycorrhiza: Symbiosis in the Soil

Subscribe to our Free Email Newsletter

Comment here