Step-by-Step Guide to Mulching for Indian Farms: Types, Process and Best Practices

Table of Contents

• Introduction to Mulching in Agriculture
• Different Types of Mulching

• • Organic Mulches
  • Inorganic Mulches

• Facts for Selecting Mulching Papers
• The Process of Plastic Mulching
• Irrigation Practices under Mulching
• Best Practices for Agricultural Mulching

Introduction to Mulching in Agriculture

The term “Mulch” means covering of soil. It covers the soil with plant residues or other inorganic substances to reduce water evaporation losses and create favourable conditions for better plant growth. Mulching helps conserve soil moisture, reduce soil temperature, reduce weed growth, and increase crop yields. It can be done organically or inorganically, depending on the requirements of the crop. Farmers in India use different types of mulching based on their crops. Let’s understand the various types of mulches used in agriculture.

Different Types of Mulching

Organic Mulches

The organic mulches are made from natural materials that decompose over time. Here are some organic mulches used in agriculture:

Straw: Straw is the widely used organic mulch in India. It comes from the grains such as wheat, oats and rice. It can be spread manually or with the help of a machine. After decomposing, the straw makes the soil fertile, which is beneficial for plant growth.

Hay: Hay is the substitute for straw. The significant difference between straw and hay is that hay is softer and made from grass. Both straw and hay reflect light from the soil’s surface and make it cool.

Wood Chips: Wood chips are used as organic mulching in agricultural fields, particularly gardens. Wood chips decompose slowly and help to retain soil moisture and control weeds.

Grass Clippings: A thin layer of grass clippings is spread over seedlings, and then a dry grass layer should be spread over the crop area. The grass clippings treated with pesticides are not used for the mulching process.

Shredded Leaves: The shredded leaves are one of the natural mulches. They prevent evaporation and break down quickly, adding nutritious organic matter to the soil.

Advantages of Organic Mulches

• The most important advantage of organic mulch is that it adds organic matter to the soil, unlike inorganic mulches.
• The organic mulch suppresses the growth of weeds effectively.
• The organic mulch reduces the evaporation rate in the garden, making the soil moisture intact, which proves to be a beneficial point in the mulching process.
• Natural or organic mulches are easy to make and, hence, sustainable forms of mulches.
• Organic mulches are less expensive than inorganic mulches.

Disadvantages of Organic Mulches

• The major disadvantage of organic mulch is the time-to-time reapplication, as it quickly decomposes and needs to be reapplied on time.
• The strong winds can quickly whisk away the organic mulches, so they are inappropriate for inclined surfaces.
• Organic mulch sometimes is adulterated with seeds of weed plants. As the weeds germinate, they tend to compete with the main crop.

Inorganic Mulches

The inorganic mulches do not break up quickly and are used for long-term weed control. Inorganic mulch includes materials like plastic film, landscape fabric, gravel, stones, or rubber mats. However, the most widely used inorganic mulch in India is plastic film. Let’s understand plastic mulching in more detail.

Plastic Mulching: The covering of the soil’s surface with a layer of plastic film is known as plastic mulching. These mulches are impermeable to water, preventing direct evaporation of moisture from the soil and thus limiting water losses and soil erosion over the surface. As a result, it conserves more water than organic mulching. Today, most LLDPE-based plastic mulch is used in our country.

Advantages of Plastic Mulching

• Plastic mulching is entirely impermeable to water.
• Plastic mulching does not break down quickly and lasts longer than organic mulching.
• It reduces water evaporation from the soil thus helps in water conservation.
• Plastic mulching is the most beneficial type of mulching for controlling weeds effectively.
• It can act as a barrier to soil pathogens.
• It decreases the availability of water-containing salts.
• It retains the soil moisture, thus improving the soil fertility.

Disadvantages of Plastic Mulching

• Plastic mulching is costly when compared to organic mulches.
• It creates environmental pollution due to the use of plastic in it.
• It isn't easy to spray top-dressed fertilizers in plastic mulching.

Facts for Selecting Mulching Papers

Selecting the right mulching paper is a tricky task. But do not worry, we have got you covered! With the factors we have listed below, you can choose the right mulching paper that is suitable to boost your crop production.

Thickness: Choosing the correct thickness of your mulching paper is necessary. The durability of the mulching paper depends on its thickness. Nowadays, thin mulching paper is sufficient and widely used in short crops like vegetables. The thickness ranges from crop to crop; for vegetables, 15 microns to 30 microns is used; however, for orchid crops, film thickness ranges from 100-150 microns. Thin mulching paper is less expensive, but thick mulching paper is more durable.

Quality: The quality of your mulching paper is a critical factor in crop protection. A high-quality mulching paper with good thermal resistance characteristics will offer greater durability, ensuring your crops are well-protected.

Width: The width of your mulching paper is an important consideration for effective crop spacing. Ensure that the width between your crop rows is approximately 1 to 1.5 meters to achieve optimal results.

Colour: Selecting the colour of the mulching paper should be your priority as the colour affects soil temperature, air temperature around the plant, sunlight reflection & soil pH level. Black and silver is the common mulching sheet used in many crops. This is suitable for almost all crops and reflects nearly 27% of the sunlight towards fruits and plants, improving the fruit's colour.

Perforations: Perforation paper has both advantages and disadvantages. Lower perforation paper is used to control better fertilizer distribution, whereas water stagnation problems can be avoided with a higher perforation sheet. However, weed control is a problem here.

The Process of Plastic Mulching

A standard mulching process is followed in agriculture, except for some techniques that vary from crop to crop. Let's take an example of a vegetable crop mulching step-by-step.

• Pre-plant mulching is required in each type of crop, where mulching should be punctured at the required distances as per crop spacing and transplanted in the holes.
• For crops like vegetables, it's crucial to use a thin mulching paper. This specific type of mulching paper is ideal for these crops due to its ability to regulate soil temperature and moisture, providing the best conditions for growth.
• Roll the mulching sheet from one end to the other length of the planting row.
• Apply the required fertilizer before mulching, and then insert the mulching sheet into the soil. Seeds are sown directly through the holes made in the mulch film.
• The seedlings could be planted directly into the hole in the case of transplanted crops.
• When rolling the mulching sheet, it's important to avoid rolling it too tightly. Excessive tightness can lead to shrinkage, which can negatively affect the crops. So, always be cautious and attentive during this step.
• Another important point to remember is to not cover the mulching film at the hottest time of the day. This responsible action will prevent the film from expanding excessively, ensuring the best conditions for your crops.

Irrigation Practices under Mulching

• Lateral pipelines, which are crucial for the distribution of water, are strategically placed under the mulch film in drip irrigation. This film serves to conserve moisture, suppress weed growth, and enhance soil structure.
• In flooding, the irrigation water passes through the semi-circular holes on the mulch sheet.
• Regulate the water flow through a small pipe or through the holes made on the mulch film by keeping the laterals and drippers on top of the mulch film in the inter-cultivation practices.

Best Practices for Agricultural Mulching

• Apply the mulching film at the right temperature for crop planting. The soil should be moist and well-prepared at the time of mulching application.
• Avoid the direct contact of mulch with the stems of the plant as it can cause diseases to the crop.
• Apply a mulch with a distance of at least 2-4 inches to get better weed control, moisture retention, and temperature regulation.
• Monitor the mulch layer annually.