A temporal analysis of the consequences of the drought regime on the water footprint of agriculture in the Guadalupe Valley, Mexico.

Changes in water availability have a substantial impact on the sustainability and maintenance of agriculture, with water footprint (WF) being a robust methodology to assess these transformations. The Guadalupe Valley is one of the places with the highest agricultural production in Mexico. Despite its semi-arid climatic conditions, it provides high-quality crops that are well-positioned in the world. The historical trend of rainfall and temperatures between 1987 and 2017 was analyzed to identify climatic patterns in the territory. Through the calculations of the water footprint of Grapevine and Olive crops, the sensitivity of the crops to recurrent water deficit and their adaptation in their yields to drought episodes was identified. The reduction in precipitation and occurrence of extreme temperatures have contributed significantly towards augmenting crop evapotranspiration and, consequently, intensifying crop irrigation demands. As a result, there has been an apparent increase in the consumption of WFagricultural since 2007. Thus, the period of highest WFagricultural consumption was 2014 (Extremely dry), as opposed to 2011 (Very wet). In particular, the lowest WFgreen consumptions were observed in extremely dry years, that is, > 20% of the WFagricultural intensifying drought events. Therefore, these periods were compensated with higher uses of WFblue and WFgray, which are inversely correlated with precipitation, where vine crops consume 73% more WFagricultural compared to olive plantations, showing greater interannual variability. These results contribute to analyzing the temporal evolution of water consumption for agriculture, providing a basis for rational water use strategies.

Diversity of Agaricomycetes in southern South America and their bioactive natural products.

Fungi have a unique metabolic plasticity allowing them to produce a wide range of natural products. Since the discovery of penicillin, an antibiotic of fungal origin, substantial efforts have been devoted globally to search for fungal-derived natural bioactive products. Andean region forests represent one of the few undisturbed ecosystems in the world with little human intervention. While these forests display a rich biological diversity, mycological and chemical studies in these environments have been scarce. This review aims to summarise all the efforts regarding the chemical or bioactivity analyses of Agaricomycetes (Basidiomycota) from southern South America environments. Overall, herein we report a total of 147 fungal species, 21 of them showing chemical characterisation and/or biological activity. In terms of chemical cores, furans, chlorinated phenol derivatives, polyenes, lactones, terpenes and himanimides have been reported. These natural products displayed a range of biological activities including antioxidant, antimicrobial, antifungal, neuroprotective and osteoclast-forming suppressing effects.

Water footprint and virtual water flows from the Global South: Foundations for sustainable agriculture in periods of drought.

Freshwater availability has decreased alarmingly worldwide, with agriculture playing a vital role in this trend. The assessment of the agricultural water footprint (WFagricultural) and virtual water flows (VWF) is fundamental not only in local water resources management and protection, but also in our understanding of the synergies between local water consumption and global markets. Thus, the WFagricultural - broken down into its components (blue, green, and gray) - of the leading 21 crops (grouped in fruit, legumes, cereals, and vegetables), grown in four basins with the most significant agricultural activity in central Chile was determined, estimated in two consecutive years 2017-2018. In addition, due to their great importance in exports, VWFs were assessed, establishing connections according to their origins and destinations. The results show that the green and gray water footprints increased significantly in the south-central basins, while blue water consumption increased in the basins of the central zone, reflecting an evident WFagricultural transition in accord with latitude and climate conditions. Furthermore, VWF showed an annual increase of 44 %, in about 116 destinations, with Asia, Europe, and North America being the preferred destinations, with annual variations of VWFblue- gray associated with increases in exports of apples, cherries, grapes, blueberries, and walnuts, market preferences and growing areas. The present study is an initial step toward sustainable agriculture in a commodity exporting country, one that is relevant in the exploitation of virtual water yet faces severe water deficit problems, distribution, and local water policies. Therefore, contributing to encouraging the efficiency and value of water in the process of a new institutional framework.

Mycoremediation of oxytetracycline by marine fungi mycelium isolated from salmon farming areas in the south of Chile.

Antibiotics are extensively used for growth promotion purposes in intensive aquaculture. In Chile, the use of antibiotics in salmon farming is excessive, approximately 62 times more than is used in Norway. In the salmon industry, antibiotics such as oxytetracycline (OTC) are administered in the diet, both in the juvenile stage in freshwater and in the fattening process of salmon in marine sectors. We have investigated the fjords of Chile, where many salmon farms are located, searching for fungi able to degrade this tetracycline antibiotic. We have evaluated the OTC degradation ability of the following; Penicillium commune, Epicoccum nigrum, Trichoderma harzianum, Aspergillus terreus and Beauveria bassiana, isolated from sediments in salmon farms from southern Chile. In all these fungal strains, the amount of OTC decreased in the culture medium, as adsorbed in the mycelia, after the third day of exposure. These strains were capable of degrading OTC at remarkable rates up to 78%, by the 15th day. This is the first study showing that the mycelium of these fungal strains has the ability to degrade OTC. We believe the knowledge produced by these results has the potential to serve as a basis for implementing a bioremediation process in the near future.

Understanding agricultural water footprint variability to improve water management in Chile.

Understanding water consumption is crucial for sustainable management of water resources. Under climate change scenarios that project highly variable water availability, the need for public policies that assure efficiency and equity in water resources is increasing. This work analyzes the case of the Cachapoal River agricultural basin (34°S 71°W), which presents temperature increases and a precipitation deficit, with a drought period that began more than eleven years ago having significantly decreased water availability. Water consumption in the basin for food production was determined from the agricultural water footprint (WFagricultural), using the green (WFgreen), blue (WFblue) and gray water footprint (WFgray) indicators, which were measured in the upper, middle and lower basin under conditions of climate variability (dry, wet and normal years). The greatest WFagricultural was established in the dry year, with a total of 18,221 m3 t-1, followed by 15,902 m3 t-1 in the wet year and 14,091 m3 t-1 in the normal year. Likewise, the greatest WFblue and WFgray, of 12,000 m3 t-1 and 4934 m3 t-1, respectively, were also observed in the dry year. The greatest WFgreen, 2000 m3 t-1, was calculated for a normal year. The 63% of agricultural area of the basin was covered by avocado (Persea americana), olive (Olea europaea), corn (Zea mays) and grape (Vitis sp) crops, which presented the greatest WFagricultural. This water footprint data provides a quantitative basis for the assessment of water consumption and degradation, considering agricultural production and its multiple variables. The success of the application of these results lies in the use of indicators to understand change processes and complement future water allocation plans with more rational water management models.

Morphological response to salinity, temperature, and pH changes by marine fungus Epicoccum nigrum.

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25 °C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 µm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.