Biodegradable mulch film made of starch-coated paper and its effectiveness on temperature and moisture content of soil

A biodegradable mulch paper (BMP) was made from pea starch and brown kraft paper. Brown kraft paper (KP) was brushed with pregelatinized starch solution on one side evenly at 0.095 kg starch solution per square meter and dried at room temperature for 48-72 h. The BMP, uncoated KP, and commercial plastic weed barrier (WB) had similar thicknesses, from 0.15 to 0.22 mm. However, the tensile strength (TS) of KP was much higher than BMP and WB, whereas the tensile strengths of BMP and WB were similar. The KP had the highest values in elastic modulus (EM), indicating brittleness and rigidity. The WB had the lowest elastic modulus value. Water vapor permeability (WVP) of BMP was lower than that of KP, resulting in 4.57 and 10.28 g mm kPa(-1) h(-1) m(-2), respectively. Both the BMP and KP could keep the soil more humid than the WB did. Soil temperature under BMP and KP was lower than those of WB and bare soil. The field experiment results also showed that BMP and KP prevented the growth of weeds.