Organic and Inorganic Mulching for Vegetable Gardening to Get Quality Food

Mulch is the application of organic or inorganic material on the top layer of soil for enhancing the overall growth and development of plants. The use of organic mulches is much more sustainable than inorganic mulches but both mulches have their importance and serve different purposes. This article is focused on the types of mulch, benefits, and management practices to improve plant production on a sustainable basis.

Organic mulch is obtained after decomposition so mulching should be done at least one month before vegetable growing so that good organic matter can be added to the soil for proper decomposition. The decomposition of organic material and activities of soil biota also improves the soil structure, and its physical, chemical, and biological properties.

Although the type of mulching material to be used is dependent on geographical conditions and the type of vegetables to be grown. The size of mulching material to be used must be properly reduced into smaller pieces for easy and effective decomposition. Even though larger materials can also be used for mulching, but the breakdown of larger components requires more time for decomposition and thereby effective results may not be achieved in a short time.

Purpose and Benefits and Mulch

Soil mulching is important for disease control, moisture conservation, soil protection against erosion, nutrient provision to the soil, regulation of soil temperature, weed management, and enhancing the overall looks of vegetable gardens. Gardeners always have a choice to select the best mulch for vegetable gardens according to the soil type and prevailing climatic conditions.

There are numerous benefits of mulching in vegetable gardening and the most significant ones include the following:

Reduced Landfill Waste: The use of organic waste such as wood, pine bark, leaves, twigs, and other wooden products is supposed to end up in landfill sites. The application of these wooden materials to vegetable gardening after proper cleaning and treatment will greatly reduce the burden on landfill sites. Results of scientific studies have shown that about 60% of the wooden material going to the landfills is compostable and its use can help to improve soil fertility and food production.

Improved Soil Fertility and Productivity: About 30% of organic matter must be added to vegetable gardens to improve soil health and fertility. Usually, the soils in many areas are inorganic and cannot sustain the growth and activities of beneficial soil microbes and soil biodiversity. In addition to organic material, compost or mulch helps to feed the soil food web, and in return, the activities of soil biota help to feed the plants. Thereby the need for synthetic fertilizers application is greatly reduced and growers can save a good amount by reducing the fertilization needs.

Suppression of Soil Borne Diseases: Many plant diseases are supported by the soil systems and many of these diseases can easily infect the plants due to foliage contact and interaction with the rooting systems. The splashing action of water during rain or irrigation can cause movement of these pathogens from soil depths to the plant surface or the plant roots and helps pathogens to make easy contact with the plant for infection. The probability of disease development due to this mechanism can be greatly reduced by the mulching in vegetable gardening. Therefore, mulching could reduce the risk of pathogens and disease development for vegetable production.

Suppression of Weeds: Usually the growth of weeds is inevitable in the vegetable gardens but weed emergence and development can be significantly reduced by proper mulching. The mulch cover does not allow the penetration of sunlight to the weed seeds in the soil and thus their germination and growth are suppressed. Moreover, the mulch is applied in the form of a layer and weeds cannot get enough space for emergence. Even if some weeds can manage the germination their further development will be smothered by the mulching layer.

Soil Protection from Erosion and Runoff: Generally, the top layer of soil in vegetable gardens has permeable and soft nature and is greatly prone to losses due to erosion and runoff by the splashing action of rain. Moreover, some areas have crusted soils and such soils can go through losses due to wind erosion. Mulching application in vegetable gardens can greatly protect the soil from losses by the action of wind and water. Therefore, the fertile layer of the soil can be maintained in the vegetable gardens for maximized production.

Regulation of Soil Temperature: Most of the feeder roots of the plants and especially vegetables grow best under the top few inches of the surface soil. The health of these roots is a major concern as they are extremely sensitive to freezing and heating temperatures. The mulching layer plays the buffering action and helps for the temperature regulation of the soil surface and soil profile.

Moisture Retention: Mulching is helpful for moisture conservation in the vegetable garden and helps to minimize water losses due to infiltration, seepage, and evaporation. This encourages the development and good growth of plants under limited water conditions.

Types of Mulch

Based on the composition and elemental profile of the mulch material, mulch is divided into two major types organic and inorganic. Both types of mulches offer numerous benefits to improve the growth and development of vegetables by multiple times. The selection of the right type of mulch according to the type of vegetable to be growing and prevailing environmental and climatic conditions can greatly improve food production and food security throughout the globe.

Organic Mulches

Organic mulching is the addition of natural materials to vegetable gardens and is an inexpensive and cost-effective solution to improve overall growth and production. However, these natural materials will decompose and growers have to reapply the mulch layers. Although organic fertilizers are ideal choices to improve production but can invite mold, slugs, and fungi to the vegetable gardens. So careful management practices are required to reduce the occurrence of slugs, fungi, molds, and certain other diseases.

• Leaves

The leaves of trees, plants, vegetables, and shrubs are the ideal choice for mulching as these can be easily collected from the yards, streets, parks, and gardens. The collected leaves must be free from contaminants as otherwise, they can pose serious pathogenic threats to the growing vegetables. Although growers have the choice to apply the leaves directly in the garden in the form of the layer their application after proper composting can even produce more benefits. Leaves are rich sources of nutrients and can greatly improve soil fertility and plant nutrition and therefore the need for the application of synthetic chemical fertilizers is reduced.

• Shredded Paper

This paper has easy and plentiful availability and is the best choice for mulching due to its biodegradability. Generally, soy-based inks are used in the modern age so the use of shredded paper will not cause any health concerns for vegetable consumption. It is a great choice for mulching the plants in the low tunnel or hoop house. This paper can be directly added to the mulch layer on the vegetable garden but its addition to the soil after proper composting can generate multiple benefits.

• Cocoa Mulch

Cocoa beans and cocoa shells are important mulching materials but only a little portion of coca mulch should be mixed with the other mulching material. Usually, coca mulches are treated with certain chemicals and can cause potential risks to the soil biodiversity, beneficial insects, and pets.

• Grass Clippings

Grass clippings are easy to use and free mulching material and can be easily applied in the form of a layer. However, the use of fresh grass cutting should be avoided for mulching as it can cause fungal development and disease emergence.

• Pine Straw

Pine straw is a commonly used mulching material in many parts of the world as it has a stable structure and its breakdown is slow. It has acidic nature, but its application as mulching material will not affect the pH of vegetable gardening soil. However, the spreading of this material is difficult and requires good skills for effective application and better results.

• Straw or Hay

These materials are most widely used as mulch as they are easily available in gardening centers, farm suppliers, and home improvement stores. Both straw and hay are easy to spread in the vegetable garden and greatly improve the overall looks of landscapes. Straw is obtained from the grain crops and the stalk of a grain crop is used for making the mulch. Seed heads of grain crops are not used for making straw and therefore they can be easily decomposed and thereby help to improve the soil quality of vegetable gardens.

Whereas hay is obtained from the grasses such as bluegrass and fescue and often contains seed heads. It is important to ensure that there has been no application of synthetic chemicals on the grasses as otherwise, it can cause negative influences after mulching.

• Garden Compost

Compost produced by using food waste, manure, gardening products, and other organic materials could be used for mulching the vegetable gardens. Compost should be well cooked and must be free from contaminants as otherwise, it can enhance the probability of food-borne pathogens. Compost is a slow-release but consistent source of nutrients and acts as an insulation layer to protect the soil against temperature stress and drought conditions. The layers of compost can also be added along with other types of organic and inorganic mulches.

• Wooden Chips and Tree Bark

Wooden chips and barks and commonly used and popular type of mulching materials because they are inexpensive and are most efficient than other types of mulching materials. These are byproducts obtained from the lumber industry and are sold in packaging after drying. They are dyed in different colors and growers can select the best possible color as per their personal preferences. However, it is important to check the type of color and safety profile of dyed materials before purchasing and direct application to the vegetable gardens.

Inorganic Mulches

Inorganic mulches are manmade materials and are used to cover the soil for protection against erosion, weed control, and temperature regulation. The decomposition rates of inorganic mulches are slower and therefore they stay for longer times. Initial installation of inorganic mulches is a costly process, but they produce more cost-effective results as there are no requirements for re-topping or reapplication. However, the biggest disadvantage of using inorganic mulches is that there is no addition of nutrients due to decomposition. Furthermore, improper management and installation can completely prevent the entry of nutrients into growing soil.

• Black Plastic

The addition of a black layer on the topsoil of the vegetable garden helps to reduce the growth of weeds. However, long-term exposure to sunlight can cause its breakdown into smaller pieces. Moreover, it also helps to increase soil temperature and therefore is an ideal choice to grow vegetables in the winter season and cold areas. Application of organic mulch on the black plastic layer is highly recommended to avoid overheating.

• Landscape Fabric

Landscape fabric is essentially helpful to reduce the emergence and growth of weeds. It is a great option in areas having abundant gravels and rocks as it helps to keep them away from the delicate roots of growing vegetables. Moreover, it allows easier removal of gravels and rocks and allows proper decomposition and mixing of organic mulches and compost lying underneath it.

• Stones and Gravels

Stones and gravels are excellent mulches for the areas where good drainage and additional heat are required for growing plants. Although it is difficult to spread a balanced layer of stones and gravels on the topsoil in vegetable gardens, once it is done it can offer numerous benefits. Decorative stones and rock mulches can also be used for improving the overall looks of growing spaces and vegetable gardens. However, rock and gravel mulching does not add nutrients to the soil, and therefore organic and inorganic fertilizers must be applied to improve the soil fertility levels and plant production.

• Rubber or Plastic Mulches

Chips of rubber and plastic are easily available in the markets and their balanced and controlled application is essentially helpful to improve the soil temperature in cold areas. Moreover, it also helps to reduce the chances of disease growth and development. Therefore, inorganic mulches are also helpful to reduce the burden of dangerous synthetic chemicals. Usually, the rubber mulches are made from recycled and ground tires and the use of recycled materials is always a plus point to achieve sustainability. Rubber mulches are available in different colors and can be used to enhance the looks of vegetable gardens. However, there are some concerns about the toxicity of rubber materials for vegetable garden mulching.