WHAT IS MULCH?
Mulch is a layer of decaying organic matter on the ground. Mulch occurs naturally in all forests; it is a nutrient rich, moisture absorbent bed of decaying forest leaves, twigs and branches, teeming with fungal, microbial and insect life.
Natural mulch serves as a “nutrient bank,” storing the nutrients contained in organic matter and slowly making these nutrients available to plants. All forms of plant life from the ground layer to shrubs and trees thrive, grow, shed organic matter, die off and decay, in a complicated cycle of nutrients.
Mulch should never touch the stems of plants as it can cause disease. Green layers are typically laid first, and then topped with brown layers. Apply a layer of mulch that is 1 to 4 inches thick—less in wet/warm areas and more in dry/cold areas.
When choosing your mulch materials, watch out for herbicides. Certain mulches, like grass clippings and straw, can be laden with herbicides that will contaminate the soil and reduce plant vigor. If you intend to use either of these materials in your garden, it will be wise to know their source.
TYPES OF MULCHES
- ORGANIC MULCH
Organic mulches are those natural origin materials which can decompose naturally, like agricultural wastes which are used as mulch, such as bark chips, grass clippings, wheat or paddy straw, plant leaves, compost, rice hulls, and sawdust, etc.
It decays over time and it increases the water holding capacity of soil.It also provides the soil with nutrients as it breaks down. It also improves water use efficiency indirectly. A mulched layer restricts the weed growth by obstructing light penetration to the soil surface. Lower weed prevalence significantly improves water use efficiency.
However, among organic materials, there is a wide range of choices each with different characteristics and suitability for different growing conditions. Some of the organic mulching materials which are commonly used are described below.
This is one of the richly available organic mulch in agriculture. The different types of grass clipping are widely available. But the application fresh grass clipping is restricted because the root clippings of the grass may start regrowth and cause competition to the main crop so the dried grass is always preferred to use as mulch.
Paddy, Wheat and rice straw are usually used as mulch.
Even though the straw has low nutritional status after the decomposition the soil becomes more fertile and it has long life span in the organics (dry leaves, weeds, grass, etc.)
The combined sheets of thickness 23 cm are ideal for mulching, however these sheet of newspapers are pasted with the help of gravels or pebbles.
However, the usage of newspaper mulches is restricted in high windy areas.
These are abundantly available organic mulching material with easy degradation and good for mulching.
Collection and spreading is also quite easy in the field but due to light weight the scattering is restricted. By putting the wood barks, small twigs in the crop row on these dry leaves restricts the further movement.
Wood Bark clippings:
The use of wood bark clippings as mulch is more advantageous because they contain more moisture and retains this moist for longer periods and helps in the supply of moisture to the growing crop.
But, the availability of wood bark clippings is rare and sometimes may cause phytotoxicity.
It is obtained as the finished product in the saw mills. But, due to high C:N ratio decomposition is very late. However it retains the moisture for longer periods.
It is one of the panaceas for the soil fertility status improvement.
It improves the soil physical, chemical and biological properties and enhances the organic carbon content which in turn improves the water holding capacity of the soil
- INORGANIC MULCHING
Inorganic mulches are man-made material or anything like a rock that cannot be broken down by soil organisms.
Inorganic mulches, like plastic sheets, are easy for handling and look a good choice due to its durability, but are non-recyclable and are not environment-friendly.
ADVANTAGES OF MULCHING
Mulch Insulates and Protects:
It insulates soil to protect soil organisms and plant roots from extreme weather, as well as insulate them from sudden fluctuations, such as freezing temperatures, drying sun or compaction from heavy rains.
Mulch Improves Diversity and Soil Health:
It protects soil organisms, like worms, insects, and soil microbes, which will help protect against pests. These soil critters work double-duty.As the soil organisms break down the mulch, it will enrich the soil.
Mulch also helps to prevent soil erosion, allowing you to keep more of your healthy soil right where you want it, in your garden.
Mulch Regulates Moisture:
Because mulch will reduce evaporation, it helps maintain even moisture level, protecting soil organisms and plant roots from shock and cutting down on the need to water.
Mulch Reduces Weeds:
This works in two ways,
First, reducing the amount of sunlight weed seeds are exposed to so fewer germinate,
And second, by preventing weed seeds from settling on soil and germinating. Researchers at Michigan State University discovered that the brown leaf mulch’s suppression of weeds increased when paired with a green mulch source, such as grass clippings
DISADVANTAGES OF MULCHING
- Heavy mulching over a period of years may result in a build-up of soil over the crown area of plants.
- The cost of some materials can be a drawback to large-scale mulching.
- Also, some mulch are not readily available.
- When using sawdust and wood-chips as mulch, nitrogen starvation sometimes occurs
In addition to the underground benefits from regular mulching there are other, aesthetic reasons to mulch. It provides the landscape a fresh, new look, much like newly painted siding, or clean seal-coating. It affords the plant the best possible access to nutrients, air space, and water in otherwise limiting soils.
Reapplication of mulch will produce a substantially healthier, more productive plant in your landscape.