Polymer Composites for Mulching Coatings

The film-forming composites from poly(vinylalcohol), cattle horn mealand glycerolare proposed in this presentation for the formation of coatings for mulching of plants cultivated in pots and containers.Poly(vinyl alcohol)was used as a binder. Horn meal was used as the nitrogen containing filler. Glycerol was used as a plasticizer.The effect of the particle size of horn meal on the mechanical properties, water vapour permeability, solubility of the films cast from the composites was studied. The decrease of the particle size of the filler leads to the increase of tensile strength and of elongation at break and to the decrease of water vapour permeability of the films. In addition, the decrease of the particle size of the filler leads to the increase of the amount of water soluble nitrogen in films. The composites were used for the mulching of the tomato sprouts cultivated in pots. For the preparation of mulching coatings the liquid mulching composition was spread out on the surface of the growing media. After evaporation of water the polymer coatings, acting as the mulch films, were obtained. The effect of the particle size of horn meal in the mulching composition on the quality of mulch coatings, the rate of evaporation of water from the growing substrate and on plant growth was studied.It was established that the proposed mulch films retain moisture in the pots and stimulate growth of sprouts.