Assessment of the vineyard water footprint by using ancillary data and EEFlux satellite images. Examples in the Chilean central zone.

The increase of vineyard's water consumption due to the Global Warming Phenomenon (GWP) has forced the winegrowers to strengthen their irrigation and water stewardship efforts, intended for maintaining this resource's long-term sustainable use. Due to water being a limited resource, implementing the Water Footprint (WF) concept in winegrapes production provides helpful information for sustainable water stewardship. Currently, an automated version of the satellite-based METRIC (Mapping Evapotranspiration with Internalized Calibration) model, the Google Earth Engine Evapotranspiration Flux (EEFlux) platform, has been suggested as an alternative to analyzing the spatial variability of an entire field's water consumption throughout the growing season. This work aimed to evaluate the potential application of the EEFlux satellite's actual evapotranspiration (ETa) products and ancillary field data to obtain the WF blue (WFb) and green (WFg) of six commercial vineyards placed in the Chilean central zone. Firstly, the reliability of the daily actual evapotranspiration data from EEFlux (ETa EEFlux) was assessed against measured ETa data, using an available database from previous studies. The results of ETa EEFlux estimations against measured ETa were impressive, presenting a root square error (RMSE) of 0.8 mm day-1. The satellite-derived crop coefficients (Kc Sat) allowed to estimate the total WF of each vineyard, in a range of 200 to 900 m3 t-1, showing an average relative error (RE) of 101%, between the satellite-based WFb (WFb Sat) and those calculated from irrigation records (WFb). These results reflected the particular conditions of each vineyard and can be considered reasonable since they were estimated from ancillary data and EEFlux products. This study provides new insights that may represent opportunities to sustainably managing the irrigation of vineyards.

A simple method to identify areas of environmental risk due to manure application.

The management of swine manure is becoming an important environmental issue in Chile. One option for the final disposal of manure is to use it as a biofertilizer, but this practice could impact the surrounding environment. To assess the potential environmental impacts of the use of swine manure as a biofertilizer, we propose a method to identify zones of environmental risk through indices. The method considers two processes: nutrient runoff and solute leaching, and uses available information about soils, crops and management practices (irrigation, fertilization, and rotation). We applied the method to qualitatively assess the environmental risk associated with the use of swine manure as a biofertilizer in an 8,000-pig farm located in Central Chile. Results showed that the farm has a moderate environmental risk, but some specific locations have high environmental risks, especially those associated with impacts on areas surrounding water resources. This information could assist the definition of better farm-level management practices, as well as the preservation of riparian vegetation acting as buffer strips. The main advantage of our approach is that it combines qualitative and quantitative information, including particular situations or field features based on expert knowledge. The method is flexible, simple, and can be easily extended or adapted to other processes.