Evaluation of a Paper Mulch Made from Recycled Materials as an Alternative to Plastic Film Mulch for Vegetables

The objective of this study was to explore the feasibility of a paper film mulch fabricated from recycled waste products as an alternative to plastic film mulch for vegetable crops. Experiments were conducted to determine whether treatment with vegetable oil and/or elemental sulfur would retard the breakdown of mulch paper in contact with soil. Both unused and waste cooking oil significantly delayed paper decomposition and loss of tensile strength in laboratory and greenhouse tests, and sulfur further retarded breakdown. Oil treatment increased light transmission of kraft paper. In field experiments, soil temperatures were significantly higher under oiled paper than in bare soil or unoiled paper, whereas this was not true for black polyethylene (PE) mulch. However, increased light penetration also allowed weed growth beneath the oiled paper, which exerted pressure against the film, causing it to tear at about the same time that unoiled paper failed due to decay at the soil line. Sulfur also did not increase mulch longevity under field conditions. Tomatoes [Lycopersicon esculenrum (L.) Mill.] grown in a commercially available black paper mulch showed similar yields and earliness to tomatoes grown in black PE mulch, even though Ule latter resulted in slightly higher soil temperatures. The black paper mulch is considerably more expensive than black PE, but recycled kraft paper can be obtained in large rolls at lower per-hectare cost than plastic film mulches.