A System for Making and Deploying Oxide‐Coated Plastic Films for Environmental Assessment of Soils

Abstract

Core Ideas IRIS films document reducing soil conditions. IRIS films perform the same as IRIS tubes. IRIS films permit easy acquisition of two‐dimensional images. The IRIS film deployment system protects IRIS from abrasion or scratching. IRIS films require 5% of the storage volume of traditional IRIS tubes. The documentation of reducing conditions in soils is important in the study, monitoring, and delineation of hydric soils and wetlands. Over the last decade, IRIS (Indicator of Reduction In Soils) technology has moved from the periphery into common use in hydric soils studies. Their appeal has been their ease of use and their conceptual simplicity, and IRIS technology has been approved by the US National Technical Committee for Hydric Soils (NTCHS). Recent developments in IRIS applications have also utilized Mn oxide paint, in addition to Fe oxide paint. While IRIS technology has encompassed a variety of forms, polyvinyl chloride (PVC) tubes are used most commonly. There are, however, challenges when using traditional PVC IRIS tubes. These include: (1) difficulty in acquiring a two‐dimensional image from a three‐dimensional cylindrical structure; (2) abrasion or scratching of the tubes during transport and on insertion (especially in sandy or dense soil conditions); (3) expense of shipping due to their weight and size; (4) long term storage issues; (5) general environmental and/or sustainability concerns with using non‐reusable plastic tubing. This paper describes a system for the delivery and installation of oxide‐coated plastic films in soils. Field testing of both Fe‐coated and Mn‐coated devices demonstrates that data provided by films does not differ significantly from data provided by tubes. However, many of the problems and issues that have plagued the use of IRIS tubes are eliminated by use of IRIS films.