The present invention relates to biodegradable cross-linked alkyl polysaccharide dispersion materials for coating on lignocellulose sheets as a promising alternative to traditional plastic mulch in sustainable agricultural practices and process for preparation thereof. More particularly, the present invention relates to biodegradable cross-linked alkyl polysaccharide dispersion coating material coated on lignocellulose sheets having tensile strength 15‒20 MPa, tensile index of 25‒30 N.m/g wherein the coating dispersion material is obtained from the Michael addition reaction of polysaccharide (chitosan), acrylic crosslinker and further alkylation in presence of alkylamine in 93%‒95%yield. The aim of the invention is to mitigate environmental pollution and reduce dependence on non-renewable resources. The present invention provides a method of coating to prepare water repellent lignocellulose sheet/paper with a stability of 50‒70 days in outdoor environmental conditions and biodegradation in soil within 30‒45 days.