Paper Based Mulches as an Alternative to Polyethylene Mulch in Vegetable Production

This paper presents results of the AGRIPAP-project which aim was to develop a low cost, well performing paper mulch as an alternative for plastic mulches. Plastic mulches are predominantly made from polyethylene (PE) which is of fossil origin and it is non-biodegradable. Plastic mulch should be removed from the field after cultivation period in order to avoid mulch accumulation into soil. Due to contaminants, like soil and plant residues, waste plastic can’t be recycled but it has to be disposed in a landfill. For paper mulches, the same agricultural advantages were aimed for as those of PE mulches i.e. high yield, good yield quality, low demand for weeding, and sufficient resistance of weather conditions. The study was started by screening paper qualities suitable for mulching from a group of 32 candidate papers. Their mulching properties were tested in laboratory tests and papers were compared in field trials with biodegradable plastic, PE mulch and bare soil. The most promising paper qualities were chosen to further studies. Additives to control their biodegradability, properties in mechanized laying, impact of mulch quality (composition, color, transparency) on weather resistance, weed growth, soil temperature, and soil water content were also studied. Field experiments carried out in Finland, Turkey, Spain and Swaziland indicated that the best paper mulches performed comparably to conventional PE mulches and biodegradable plastic mulches in terms of yield, weed control, and resistance of weather conditions. Paper mulches can be mixed into soil after growing season and they don’t accumulate into soil but they are decomposed.