Tapioca starch film modified with urea and borate was prepared and studied for possible application as soil conditioner and slow release fertilizer. To reduce the hydrophilicity and reinforce the film, lignin was added into the starch-urea-borate system. The presence of lignin reduces the swelling capacity. The lignin modified film remains intact and shows good reswelling capability in water. The water retention of soil was improved by addition of film in sandy soil. The release of entrapped urea in soil was also studied. This study shows that the lignin modified starch film can act as soil conditioner as well as slow release system. © 2014 Trans Tech Publications, Switzerland.