A Study on the Liquid Mulching Film of Lignin

Liquid mulching film was prepared with technical gramineae lignin from waste pulping liquid via hydroxymethylation and then cross-linking reaction with urea or aromatic ring of lignin. Results showed the amount of lignin added had an influence on the property, viscosity and water resistance of liquid film material. This influence was little when lignin dosage was less than 30%, but turned apparent when lignin dosage was higher than 30%. The optimum lignin quantity was 30%. The growth of plant was accelerated when the concentration of liquid film material was around 1000 mg/L. Both planstic and liquid mulching film could improve soil temperature, the result of liquid film was a little worse than that of plastic film, but was better than the control. The optimum lignin dosage was 30% which had the best heat incubation effect.