Organic and biodegradable mulches

Soil profile at Montmorecy, Melbourne. The addition of compost has improved the physical characteristics and soil structure.

Organic and biodegradable mushroom compost.

Mulching, for domestic and public gardens, is considered the spreading of substances over the ground aiming to protect plant roots and soil from environmental factors such as high temperature, rain, erosion and strong winds. This blog post is focused on the type of mulches and what we have learned over the years of applying mulch.

The most common mulch that we have used over the past 20 years is organic compost and in particular mushroom compost. Also, various mulch mixes of manures and organic matter have been used.

In principal, organic mulches derive from plant material and decomposition does occur, and several important effects on the soil and on plant growth will be apparent to home gardeners. These effects are physical, chemical and biological. Physical effects improve soil structure and composition. Mulches alter the structure of the soil which usually increases root growth. The addition of organic mulches to the soil brings an almost immediate effect. Aeration is improved in clay soils, and the water-holding capacity is increased in sandy soils.

The acidity or alkalinity of soil (pH) may be somewhat affected by the use of organic mulches. Given that organic mulches are composed of plant materials, they add small amounts of nutrients to the soil through decomposition. These amounts have little effect on the nutrient level in the soil and should not be considered a substitute for fertilizer.

The biological effects of mulching are important since organic mulches serve as food for many microorganisms in the soil for maintaining and promoting soil aggregation. An additional benefit of organic mulch is that it also helps keep the soil temperature stable so that the activity of the microorganisms can continue despite unfavorable environmental effects.

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