An inflatable minirhizotron system for stony soils

Commonly used minirhizotron methodologies imply the introduction of rigid frames into the soil. This can be a problem if the hole presents an irregular surface, because the presence of gaps can modify the normal behaviour of roots growing along the soil-tube interface. Some authors have developed inflatable adaptations of the technique, but some of these still need the introduction of a rigid frame and others have the often added problem of the wall opaqueness. An inflatable adaptation of the minirhizotron technique has been developed to be used in stony soils. These kind of soils, common in many forests, as in mediterranean forested areas, would present too irregular surface holes to place rigid frames inside. The adaptation proposed allows the use of minirhizotrons in stony soils, with the added advantage of not having anything between the endoscope and the roots when recordings are made, which highly improves the image quality.