Use of the Active Sensor Optrx to Evaluate Canopy Changes and to Identify Soil Quality in Table Grape Under Integrated Nutrient Management (INM).

Integrated nutrient management (INM) is a key concept for intensive exporting horticulture in Chile. Its agronomic objective is to develop and maintain chemical, biological, and physical fertility to improve root system, to increase yield and fruit quality. Site-specific management is part of the INM, to eliminate soil limiting factors to allow the crop to express its growth and production potential. Active sensors such as the OptRx (AgLeader Technologies, Inc.), can be used to evaluate canopy evolution during the growing season and identify areas within the field that may have some soil limiting factor, particularly associated to biological processes. The canopy of different table grape fields of different varieties were evaluated with the OptRx sensor several times during the season. In some fields areas showing differences in terms of NDVI were identified and the soil sampled (30 cm depth). Soil samples were analyzed for selected chemical, biochemical and biological properties, including β-glucosidase and acid phosphatase, as enzymatic activity.

Results indicated that the sensor properly described canopy growth during the season and allowed identifying soil areas showing differences in terms of key properties used as soil quality indicators.