Organic Soil Amendments and How They Help Your Soil

Article written by Saturday6TM blogger Noelle Johnson from AZ Plant Lady.


Have you ever wondered what all the 'buzz' about compost is about? How does it work and why is everyone trying to make their own? You've probably heard about manure and have almost certainly smelled it before, but what does it do for plants? Throw in other things like blood meal and bone meal and one could certainly understand being a little confused. Let's take the mystery out of these four popular soil amendments - what they are and how they help your soil and plants.

Compost, manure, blood meal and bone meal are all organic amendments added to the soil. The word organic means that they come from natural sources, while the term amendment means 'something added.' They work in different ways, from improving the texture of clay or sandy soils to helping plants take up water and nutrients. In the end, these organic soil amendments help benefit poor soils so that you can grow healthy plants.

Compost: Compost is decayed organic matter. Gardeners and farmers have used compost for thousands of years. It improves soil texture by helping water infiltrate heavy, clay soils thereby improving drainage. For sandy soil, compost increases its ability to hold onto water for a longer length of time. Plants need oxygen around the root zone and compost improves soil aeration. Beneficial soil microorganisms break down compost slowly, releasing nutrients into the soil. Compost also improves the ability of soil to hold onto nutrients, keeping them from being flushed away from the root zone.


Manure: Like compost, manure benefits soil in much the same way - improving soil texture, drainage and water-holding capacity. It also aids in creating an environment where soil microorganisms can flourish, as they slowly break down the nutrients contained within manure such as nitrogen, phosphorus and potassium ' major elements vital for plant health, along with micronutrients.

Popular sources of manure for use in the garden come from chicken, cow, horse and rabbit. Before adding manure to the soil, it must be 'aged' or 'composted' first for at least six months. (Fresh manure will burn plants because of the high level of nitrogen present). A word of caution before using manure - if your soil is high in salts, then you probably should avoid using manure, which can have high levels of salts.


Blood Meal: This soil amendment is a great source of nitrogen, which is important for growth and maintaining healthy, green plants. An added benefit of blood meal is that the nitrogen is released quickly to plants. Blood meal is a powder made from the dried blood of livestock. It can be added in combination with compost and manure, or used alone.


Bone Meal: Another vital nutrient for plants is phosphorus, which assists in flower and root growth. Bone meal is made from the crushed bones of livestock. When added to soil, it slowly releases phosphorus into the soil. It also contains small amounts of nitrogen and calcium, which are also beneficial. Bone meal is often used for planting bulbs and growing roses.

Before adding amendments, it's a good idea to have your soil tested to see what types of soil amendments are needed. Soil test kits are inexpensive and usually available at your local nursery or you can check with your local cooperative extension office.

Adding organic soil amendments such as compost, manure, blood meal and/or bone meal to your garden soil will reward you with beautiful, healthy plants. Before heading to the nursery to buy new plants, be sure to improve and enrich your garden soil by adding one or more of these helpful soil amendments.


The Dirt from Troy-Bilt®, May/June 2014