What is plasticulture?
Plasticulture (also called plastic mulch or mulch film) is a thin plastic sheet laid over the bed or raised beds to conserve soil moisture, suppress weeds, optimize soil temperature, and keep fruit/plants clean. Drip tape is typically installed beneath the film before transplanting or seeding, and holes are punched in the film at each plant position.
Common names
- Plastic mulch, mulch film, plastic mulch
Material and typical specs
- Material: LDPE/LLDPE (low-density/linear low-density polyethylene); biodegradable options also exist (e.g., PLA/PBAT/starch blends).
- Thickness: about 20–50 microns (25–30 for a single season; 40–50 for heavier-duty use).
- Width: matched to bed width and row spacing (e.g., 80–120 cm).
- Best paired with: drip irrigation under the film.
Advantages
- Reduces evaporation and saves water
- Effective weed control without herbicides
- Improves soil temperature (warmer early in the season; cooler with light-colored films in hot weather)
- Keeps fruit clean (e.g., strawberries) and reduces soil-contact diseases
- More uniform moisture and growth, earlier harvest, and often higher yields
- Certain colors (silver/reflective) can reduce pressure from sucking pests such as aphids and whiteflies
Limitations/challenges
- Waste management and microplastics; requires proper retrieval and recycling/disposal
- Risk of overheating soil in very hot climates (choose film color wisely)
- Requires well-prepared beds and tight laying to avoid tearing
- With clear film, weeds can grow (except when used for pre-plant solarization)
Quick color guide
- Black: strong weed control; slightly warms soil; general choice for vegetables.
- Silver/black: reflective; helps deter some pests; good for warm regions and sensitive crops.
- White/black: cooler surface in summer; prevents excessive soil heat.
- Clear: transmits light and heats strongly; best for pre-plant soil solarization, not for in-season weed control.
Installation tips
1) Shape uniform raised beds and install drip tape.
2) Lay the film with a mulch layer or by hand and bury the edges with soil.
3) Punch planting holes at the desired spacing and plant.
4) Monitor irrigation and temperature; in extreme heat, use lighter film or temporary shade.
Alternatives
- Organic mulches (straw, wood chips), paper mulch, reusable polypropylene fabrics.
- If environmental impact is a concern, look for biodegradable films certified to EN 17033.
Why does plasticulture speed early growth in the combined method?
In the “combined method” (typically mulch film + drip irrigation/fertigation, sometimes with row covers/low tunnels), plasticulture accelerates early growth for several reasons:
- Warmer root zone
- Dark films (e.g., black) absorb radiation and reduce evaporation, usually keeping soil 2–4°C warmer than bare soil. By the Q10 rule, each 10°C rise can roughly double root metabolic rates; even 2–4°C can noticeably speed rooting, germination, and nutrient uptake.
- Stable moisture, less transplant shock
- Less evaporation means smaller swings in moisture and a steadier water potential. Transplants experience less shock, root faster in the first days, and leaf out sooner.
- No weed competition
- Early, season-long weed suppression leaves water and nutrients to the crop—most impactful on “earliness” in the first weeks.
- Synergy with drip and fertigation
- Drip tape under film delivers water and nutrients precisely to roots. With uniform moisture, mass flow and diffusion of nutrients (N, K, Ca, etc.) improve and fertilizer-use efficiency rises—driving stronger early vegetative growth.
- Better plant microclimate
- Less soil splash on leaves/fruit lowers certain disease pressures. Reflective (silver) films can also deter early-season sucking pests (aphids, whiteflies), letting plants invest more energy in growth.
- Salinity management and soil structure
- By curbing surface evaporation, capillary rise and salt buildup near the crown are reduced (salts tend to concentrate at film edges), so establishment is better in slightly saline soils. Soil under film also resists crusting and structural swings.
- Color-specific light effects
- Some colors shift the red/far-red ratio (e.g., red mulch in tomatoes/strawberries) and can tweak earliness and branching.
- When combined with row covers/low tunnels
- If the method includes a low tunnel or nonwoven cover, air around plants can warm by 2–6°C, boosting growing-degree days (GDD) and typically advancing maturity by a few days to two weeks.
Typical outcome in warm-season crops (tomato, pepper, melon, cantaloupe, strawberry): faster greening and establishment, earlier flowering and harvest (often 7–14 days earlier), and in many cases a 10–30% yield increase—varying with climate, film color, irrigation/fertigation, and ventilation.
Practical notes
- Cool regions: choose black or dark film. Very hot regions: white/silver to prevent soil overheating.
- Reserve clear film for pre-plant solarization, not in-season use (except special cases).
- If using row covers, ventilate at midday to prevent heat stress.
What soil and irrigation conditions help plasticulture or container growing perform best?
For plasticulture (mulch film) or container culture to shine, you need the right soil/substrate and precise irrigation. Use this quick guide to dial in your setup.
Quick comparison
- Plasticulture (field): native soil + plastic mulch + drip tape
- Container culture: lightweight soilless mix in a pot with excellent drainage
Plasticulture (mulch film in the field)
- Suitable soil
- Texture: sandy loam to loam with good drainage; very clayey/compact soils should be improved with organic matter and deep tillage/subsoiling before planting.
- Bed: uniform, slightly raised beds (to avoid waterlogging under the film).
- pH and salinity: pH around 6–7 for most vegetables; irrigation water EC preferably < 1 dS/m. In saline-leaning soils, prevent salt buildup under the film (see irrigation notes).
- Organic matter: 2–3% or higher; well-matured compost helps keep moisture steady.
- Irrigation/system
- Drip tape under the film with adequate filtration (at least 120 mesh) and even pressure; 1.0–1.6 L/h emitters spaced 20–30 cm; use two drip lines on wide beds.
- Pre-wet: bring the bed close to field capacity before laying film so roots meet moisture from day one.
- Scheduling
- Establishment (first 7–10 days): short, frequent pulses to keep moisture steady and avoid wet–dry cycling under the film.
- After establishment: irrigate based on ETo × Kc or soil-moisture sensors. With tensiometers, typical on/off thresholds:
- Sandy soil: ~10–20 kPa
- Loam: ~20–35 kPa
- Clay loam: ~30–45 kPa
- Managing salinity under film
- Because evaporation is reduced, salts migrate toward film edges; every 2–4 weeks, run a longer “leaching” irrigation (preferably early morning) to push salts below the root zone.
- Avoid heat stress
- In very hot areas, use white/silver films and irrigate in morning/evening.
- Maintenance
- Open and flush line ends weekly; if source water has high pH, occasional mild acidification helps prevent precipitation.
Container culture (pots/containers)
- Substrate and pots
- Lightweight, soilless mix: e.g., 40–60% coco/peat + 30–40% perlite/pumice + 10–20% compost/bark. Do not use garden soil in pots (poor drainage/aeration).
- Target substrate pH: 5.8–6.5 for most vegetables. Pots must have ample drain holes; saucers should allow free drainage.
- Suggested pot sizes: tomato 15–30 L; pepper 7–15 L; cucumber 10–20 L. Bigger pots favor stronger roots.
- Irrigation and feeding
- Golden rule: water each time to 10–20% leachate (to flush salts), then wait until the top layer begins to dry.
- Frequency: daily in heat; every 1–3 days in mild weather. Pot weight or a simple moisture meter helps.
- Nutrition: “constant feed” with a dilute solution at each irrigation (e.g., 1–2 g/L of a complete fertilizer) or use controlled-release fertilizer; once a week irrigate with plain water to leach salts.
- Water quality: irrigation water EC ideally < 1 dS/m; if water is hard, lightly acidify or use treated water to mix fertilizers.
- Temperature notes: dark pots heat up in sun; insulate or choose light-colored pots to keep root zones cooler.
Common mistakes and fixes
- Heavy soil/waterlogging under film: make taller beds, add organic matter, split irrigation into shorter pulses.
- Uneven wetting under film: reduce emitter spacing or add a second drip line.
- Salt buildup at the plant base: periodic leaching irrigations; if water is saline, poke small holes near plants to help salts escape the root zone.
- Container root rot: inadequate drainage or heavy watering; return to a “wet-to-almost-dry” cycle and lighten the substrate.
Quick checklist
- Plasticulture: uniform raised beds, pre-wet, clean drip tape with 120-mesh filtration, short/frequent sets for establishment, periodic salt leaching.
- Containers: airy, lightweight mix; appropriately sized pots; irrigate to 10–20% leachate; steady, dilute feeding; manage pot temperature.
