Mulch film
In agriculture and horticulture, plastic films are referred to as mulch films or horticultural films , which are used to cover the soil of beds or arable land . For the crop plants to be grown, the film is perforated at the point of sowing or planting. Mulch films are mainly used in vegetable and strawberry cultivation.
effect
The cover causes the surface of the earth beneath the film to heat up by around 2 ° C compared to the environment, which means that the plants receive better growth conditions at cool temperatures - but in summer the top soil layer can also be heated up too much. Because of the homogeneous conditions under the film, the crop plants grow more evenly. The soil under the mulch film remains loose and does not dry out as quickly. The soil fermentation and soil fertility are promoted. In addition, the use of black film suppresses weed growth on the covered areas and can thus reduce the need for herbicides . The spread of certain plant diseases (e.g. gray mold rot ) and the leaching of nutrients are also reduced. The end result is an increase in yield and an earlier ripening of the fruits. The external quality of the fruit is also improved, as the mulch film prevents the crop from becoming soiled. The disadvantage of using mulch film can be that because of the reduction in heat radiation during the night through the ground cover, the above-ground parts of the cultivated plants can be more likely to be damaged by night frosts.
materials
Mulch films are usually made of a polyethylene film, which means that they can sometimes remain under gravel paths or mulch beds for years to suppress weeds without rotting. The foil material is mostly colored black, but white (so-called milk foils) or transparent foils are also used.
Alternatively, mulch films can be made of biodegradable plastics , e.g. B. from renewable raw materials . The main advantage of these films is their compostability . As a rule, the foils rot after about three months and thus save the need to collect the foils after the harvest, especially in large farms; the rotting remains can easily be plowed under or disposed of in the compost. In addition to biodegradable films made from starch polymers , lactic acid-based films ( polylactide polymers or PLA) have also been available since 2007 , which allow longer use due to their slower biodegradation.
Due to their significantly higher price, the use of mulch films based on renewable raw materials has so far only saved costs in certain applications and their market share is correspondingly small. In a direct comparison of costs in 2006, the cost of using a biodegradable mulch film was roughly twice that of a comparable polyethylene film. However, the cost of collecting, cleaning and disposing of the polyethylene mulch film must also be included in an economic analysis.
commitment
In Germany, mulch films were used on 3935 hectares in 2008. For 2010, a market turnover of 18 million euros for mulch films made from renewable raw materials and for 2020 of 100 million euros is forecast. In order to be able to cover larger areas with foil in a short time, foil laying machines are mostly used. These lay down the film in one operation and cover the edges of the film with earth for attachment.
Individual evidence
- ↑ FKuR: Compostable mulch films made from PLA blends. Plasticker.de of August 27, 2007.
- ↑ Matthias Geuder: Biopolymers - A Perspective for Agriculture? Master's thesis at the University of Hohenheim, 2007.
- ↑ Research Association for Biological Degradable Materials eV and State Research Institute for Horticulture Weihenstephan (2009): Biodegradable mulch films from renewable raw materials - information and instructions for use. P. 5
- ↑ Michael Nusser, Patrick Sheridan, Rainer Walz, Philipp Seydel, Sven Wydra: Macroeconomic Effects of Cultivation and Use of Renewable Resources. Final report of a study for the Federal Ministry of Food, Agriculture and Consumer Protection. Fraunhofer Institute for Systems and Innovation Research (Fraunhofer ISI), Karlsruhe, Institute for Farm Management in Agriculture and Food Management at the Justus Liebig University, Giessen. Ed .: Fachagentur Nachwachsende Rohstoffe eV, Gülzow, 2007, urn : nbn: de: 0011-n-638446 .
literature
- Ulrich Sachweh (editor): The gardener, volume 3, tree nursery, fruit growing, seed growing, vegetable growing . 2nd edition, Ulmer, Stuttgart 1986/1989, ISBN 3-8001-1148-9 , p. 64.
