Walk barefoot across dry, uncovered farm soil in May, and you will understand immediately why mulching matters. The surface temperature of bare agricultural soil in India’s summer can exceed 60 degrees Celsius — conditions that would destroy the biology of any living soil, evaporate water at extraordinary rates, and bake the surface into an impermeable crust. Now walk on the same field covered with a 10-centimetre layer of paddy straw. The ground beneath is cool, moist, and alive.
This simple observation encapsulates why mulching is one of the most transformative practices in natural farming — and why it has been used, in various forms, by traditional farmers across every culture and climate on Earth.
What Is Mulching?
Mulching is the practice of covering the soil surface with a layer of organic or inorganic material to protect it from the elements, retain moisture, moderate temperature, suppress weeds, and feed soil biology. In natural farming, the focus is almost exclusively on organic mulches — materials derived from plant matter that decompose over time and contribute to soil organic matter.
The main types of organic mulch used in Indian natural farming systems are:
Straw mulch: Dried rice straw, wheat straw, or sorghum stover spread 5 to 15 centimetres thick between crop rows. This is the most commonly used mulch across rice-growing regions of Andhra Pradesh, Telangana, and Tamil Nadu. A single season’s paddy straw from one acre can mulch the same acre — a beautiful circularity.
Dry leaf mulch: Fallen leaves from forest trees, mango, teak, or neem gathered from nearby areas. Leaf mulch breaks down more slowly than straw and is excellent for orchards and perennial crops.
Living mulch: Low-growing cover crops — cowpea, methi, or clover — grown between the main crop rows. Living mulches are not simply a ground cover; they are active nitrogen fixers, green manure sources, and habitat for beneficial insects. They require more management than dry mulch but provide compounding benefits.
Crop residue mulch: Rather than removing crop residues after harvest, they are spread as mulch directly on the field. When combined with Jeevamrutha application, crop residues decompose rapidly and feed the soil.
Vermicompost as top dressing mulch: In some intensive natural farming systems, a thin layer of vermicompost is applied to the soil surface around individual plants, functioning simultaneously as mulch and targeted fertiliser.
Benefits of Mulching: What the Blanket Does
Moisture Retention
This is mulching’s most immediate and dramatic benefit. Water evaporates from bare soil through a process called direct evaporation — the sun heats the surface and water molecules escape as vapour. A mulch layer physically interrupts this process by shading the soil surface and creating a humid microclimate just above the soil.
Studies conducted in mulched versus un-mulched ZBNF plots in Andhra Pradesh found that mulched plots required 30 to 45% less irrigation to produce the same crop yield, with the difference most pronounced in the hot, dry months between October and February.
Temperature Regulation
Soil temperature affects the activity of virtually all soil organisms. Most beneficial bacteria and fungi operate optimally in the range of 20 to 35 degrees Celsius. Bare soil in Indian summers regularly exceeds 50 to 60 degrees at the surface — conditions fatal to many soil organisms. A mulch layer buffers this extreme, keeping soil surface temperatures 10 to 15 degrees cooler in summer and 5 to 8 degrees warmer in winter, dramatically expanding the window of active soil biology.
Weed Suppression
A thick mulch layer (8 cm or more) physically blocks light from reaching weed seeds, preventing their germination. In natural farming systems that avoid herbicides, mulching is the primary weed management tool. Farmers using paddy straw mulch in vegetable and row crop production report 60 to 80% reductions in weed pressure compared to unmulched plots, dramatically reducing labour requirements.
One important note: the mulch must be applied before weeds germinate, ideally immediately after transplanting or sowing. Applying mulch after weeds have already emerged is far less effective.
Feeding the Soil
As mulch decomposes, it feeds a cascade of soil organisms. Fungi are typically the first colonisers of fresh straw mulch, breaking down cellulose and lignin. Bacteria follow, along with a diverse community of mites, springtails, beetles, and earthworms that all participate in the decomposition process. The end product is stable humus — the dark, nutrient-rich, water-retaining organic matter that defines fertile soil.
A mulch layer is therefore not merely a soil cover — it is a continuous, slow-release feeding programme for the entire soil food web. Farmers who have mulched consistently for three or more years report visible changes in soil colour, texture, and earthworm populations.
Erosion Prevention
Heavy monsoon rain, particularly on sloped land, dislodges soil particles and carries them away — a process called splash erosion. A mulch cover absorbs the impact of raindrops, preventing splash erosion and greatly reducing surface runoff. This keeps valuable topsoil — the most biologically rich layer — in place.
Mulching Calendar: Season-Wise Application
Mulching needs vary by season, and timing matters:
Pre-kharif (May–June): Apply mulch before the monsoon arrives. This prepares the soil to absorb maximum rain rather than losing it to runoff, and begins feeding the soil biology ahead of the growing season.
Kharif (July–October): Maintain mulch between rows of kharif crops (paddy, cotton, groundnut, pulses). For standing paddy, moist paddy straw from the previous crop can be laid between rows after establishment.
Post-kharif / Rabi establishment (October–November): After kharif harvest, manage crop residues as in-situ mulch rather than burning. Apply Jeevamrutha to accelerate decomposition before rabi planting.
Rabi (November–March): Mulch between rabi crop rows (wheat, vegetables, mustard) to retain winter soil moisture and moderate cold temperature extremes.
Summer (April–May): Maintain heavy mulch on all perennial crops, orchards, and bare fields. This is when mulching delivers its most dramatic moisture conservation benefit.
Farmers Share Their Mulching Success
Farmers across natural farming programmes in India consistently cite mulching as the single most impactful practice change they have made.
Ramaiah, a groundnut farmer in Kurnool district, Andhra Pradesh, who adopted ZBNF practices in 2018, reports that paddy straw mulch between his groundnut rows reduced his irrigation from 12 applications per season to 7, saving both water and electricity. His soil, which was pale and hard when he began, is now dark and crumbly to a depth of 20 centimetres.
Savitribai, a vegetable farmer in Nashik, Maharashtra, began mulching her tomato and onion beds with dry leaves from the farm boundary. Within two seasons, she stopped applying herbicides entirely, finding that mulched beds required hand-weeding once rather than three times per season.
These stories are not exceptions — they are the consistent experience of farmers who give mulching a genuine trial.
Mulching asks very little: some organic material, some labour to spread it, and the discipline to leave the soil covered. What it gives in return — moisture, fertility, biology, and reduced costs — is extraordinary.
Next week, we take water conservation to the next level — exploring rainwater harvesting at the farm scale, from contour bunding and trenches to farm ponds, rooftop collection, and water budgeting for natural farms.