Soil Amendments

Fertility of the soil is important for proper plant growth. Soil amendments are additives to the soil to make the soil fertile so that it provides the necessary nutrients for the crops grown. Amendments are added to improve the physical properties of the soil including water retention, water infiltration, permeability and aeration. The common amendments include fertilizers and soil conditioners. Thus soil amendments enhance the richness of the soil to provide better environment for the roots.

Certain amendments are just placed on the layer of the soil. Mulching is an amendment that is left on the soil surface. This is done mainly to prevent evaporation and create attractive appearance. Other amendments are mixed with the soil. Burying the amendments is not a good way to improve the soil performance. These amendments must be thoroughly mixed with the soil to do their work properly. Also you must add amendments in appropriate quantities otherwise it will lead to an adverse effect.

Types of soil amendments

There are two categories of amendments - organic and inorganic. The organic amendments are made from natural products. The common organic amendments are sphagnum peat, wood chips, straw, saw dust, compost and manure. The wood chips are mainly used as mulches. These increase the organic constituents of the soil thus providing favorable environment for bacteria and earthworms that enrich the soil. The inorganic amendments are man-made and they include chemicals that are used for making the soil fertile. Though they are used for good output they will reduce the natural nutrients of the soil in the long run.

How to choose soil amendment?

The soil amendments depend greatly on the soil requirements. The types of crops that grow in the soil are important before deciding on the amendment. The other factors include the texture of the soil and its salinity. The amount of amendments depends on the duration you want the amendment to stay in the soil. Before using the amendments, they have to be tested for the organic matter and the pH content. The amendments also depend on your requirements for soil improvement. If you want the soil to improve quickly you have to choose the amendments that decompose at a faster rate. Otherwise composts can be used which decompose slowly. Sandy soils are amended to increase the moisture retaining capacity of the soil. Clay soils are amended to increase permeability and aeration. If you choose the appropriate amendments wisely you can benefit from any type of soil.

Benefits of different soil amendments

You have to add 3 cubic yards of chosen organic amendments per 100 square feet. Some soils many require 4 cubic yards but not more than that. If you add more amendments, it will lead to high salt deposits negating the purpose of using these conditioners. Wood products are added in summer to prevent evaporation and in winter to retain warmth. These will tie up the nitrogen in the soil. Hence you need to use nitrogen fertilizers to avoid nitrogen deficiency in plants. Sphagnum peat is good for sandy soils. It has high pH and used by gardeners who need acidic soil. Mountain peat is also widely used but they take more time to rejuvenate once they are used up.

Grade 1 biosolids can be used for food crops but they are not used for root crops. As these biosolids come in contact with the roots they should not be used for crops for which the roots are edible. Fresh manure contains high levels of ammonia that may affect the plant. Aged manures or composted manures can be used to solve this problem. By composting to 140F degrees the pathogens can be killed. These composted manures are used for food crops like vegetables.