Method for mulching an agricultural soil bed using a biodegradable protein material, and a mulched agricultural crop growing plot produced thereby

#1. Field of the Invention

#The present invention relates to the field of agriculture, and in particular to the mulching of agriculture soil beds using a thin protein film as a mulch layer. More particularly the invention relates to the mulching of agricultural crop growing plots by spreading a protein solution thereon and allowing the solution to dry to form a thin mulching film of protein lying over the plot.

#2. Prior Activities and Problems in the Field

#In accordance with the present invention, protein films may be used as agricultural mulches. Alkaline solutions of plant and animal proteins form films when cast and dried. Plasticizers such as glycerine may be employed as active ingredients to overcome brittleness of the protein film. In accordance with a preferred aspect of the invention, film forming protein solutions may be sprayed directly onto the soil surface to form a thin layer of film, which will then act as mulch to prevent moisture loss and provide weed control. Encapsulation of pesticides and herbicides into such films may have added advantages in controlled release applications.

#Standard film forming solutions of soy and wheat proteins may be prepared and spread onto plots using a hand held sprayer. The solutions should be spread uniformly and so as to form a thin film. The dried film may hold a mass of soil together by forming a thin crust thereon. In a field experiment, annual rye grass seed was planted, and a known amount of film forming solution was sprayed thereon. Initial observations showed inhibition of weeds 3-4 weeks after planting. Additional observations indicate that even after a 6 inch rainfall the spray mulched plot maintained a coarse texture, suggesting that the protein film provides erosion control.

#Successful implementation of biodegradable mulch technology should reduce the problems inherent in disposal of polyethylene film by replacing such film with an environmentally friendly biodegradable protein film. Approximately 180 million pounds of polyethylene film are used annually in connection with agricultural mulch applications. Assuming the direct materials cost of the film is 40% of its selling price, this amounts to an annual cost of $ 31.7 million. Moreover, direct cost of labor for mulch application and removal is estimated to be $ 30-40 per acre. After the cropping season is over, about 0.2 million cubic yards of plastic becomes landfill at a direct cost of $ 2.25 million annually to American farmers. The invention on the other hand, enables savings on equipment investment and on the labor required for removal of plastic film from the field. In this latter regard it is to be noted that protein mulches are derived from renewable and natural sources which are fully degradable. Thus, the protein films may be tilled into the soil following the cropping season. Upon degradation (3-6 weeks), mulches will serve as a nutrient source for the next crop.