Placing a layer of material on the soil surface around plants, or over the whole planting area, to conserve moisture and improve soil conditions is called:

Mulching is the practice of covering the soil surface around plants with a protective layer of material, called mulch. The mulch may be organic (such as straw, dry leaves, crop residues, grass clippings, sawdust or wood chips) or inorganic (such as plastic sheets, gravel or stones).

Benefits of mulching:

• Conserves soil moisture: it reduces evaporation of water from the soil surface, so less irrigation is needed.
• Controls weeds: it blocks sunlight from reaching weed seeds and seedlings.
• Regulates soil temperature: it keeps the soil cooler in summer and warmer in winter, protecting roots.
• Reduces soil erosion: it protects the soil from the direct impact of raindrops and from wind, and slows down runoff.
• Improves soil structure and fertility: organic mulches break down slowly, enriching the soil and encouraging earthworms.

Types of mulch:

Organic mulch: straw, rice husk, leaves, crop stubble, compost, sugarcane trash and coconut fronds. They improve the soil as they decay but need replacing.

Plastic mulch: black, silver or transparent polythene sheets, widely used for vegetables, strawberries and fruit crops. Black plastic is effective against weeds; transparent plastic is used for soil solarisation (heating the soil to kill pests and pathogens).

Mulching in India:

• Plastic mulching is promoted with subsidies under horticulture schemes, often combined with micro-irrigation.
• Crop residue mulching is encouraged as an alternative to burning stubble, especially in Punjab and Haryana, where stubble burning causes severe air pollution in winter.
• Machines like the Happy Seeder allow wheat to be sown directly into rice stubble, leaving the residue on the surface as mulch.

Why not the other options?

• ✗Tilling is ploughing or digging the soil to prepare it for sowing.
• ✗Pruning is cutting away branches or parts of a plant to improve its shape or yield.
• ✗Earthing up is heaping soil around the base of plants, as is done for potatoes and sugarcane.