Social unrest is on the rise worldwide amid deepening inequalities, environmental degradation, and job crises worsened by increasing social-environmental conflicts. In Chile, a social revolt in 2019 resulted in a national referendum in 2020. An ample majority (78.3% vs. 21.7%) voted to draft a new constitution to replace the current constitution drawn up under dictatorship. The result led to the emergence and empowerment of several organizations demanding an “ecological constitution”. In this context, we aim to analyze: (1) the main social-environmental conflicts in Chile and how they are related to the country’s current constitution, and (2) the potential drafting of an ecological constitution that addresses these conflicts. Across different industries in Chile, we observed common problems that are intrinsically related to the current constitution. This relationship seems to be perceived by Chilean citizens since a survey carried out in May 2021 found 79% support for an ecological constitution. Moreover, 105 of the 155 delegates to the constitutional convention proposed three or more environmental principles to be included in the new constitution. A potential ecological constitution entails principles that would improve the current situation of social-environmental conflicts in Chile. Based on our analysis, we recommend the establishment of watershed-based “territorial rights” in the new Chilean constitution to improve sustainability and environmental justice.

Intensive agriculture has led to several environmental impacts, such as soil erosion, water scarcity, and pesticide pollution. Despite the increasing research advocating greener agriculture, the transition into sustainable agriculture practices has been slower than expected. Then, why are we stuck in this transition? In this scientific essay, we aimed to answer this question not only by analyzing agricultural systems but also by the associated actors. Specifically, this scientific essay analyzed and discussed how agricultural systems integrate with the surrounding market, society, and policies. We made a literature review of the impacts of intensive agriculture on global change and an analysis of greener agricultural systems. Then, we analyzed how the market, society, and policies can influence the transition from intensive agriculture to greener agricultural systems. In addition, we complement that literature review with a survey made in Chile. Our analysis highlighted ecological intensification (EI) as the most promising production system in terms of sustainability. However, the most sustainable was not necessarily the most supported by the market and society. We found a disconnection between consumers' environmental concerns and what they support when buying foodstuff. Our survey showed that most people are aware of soil degradation and high-water consumption, but above all, they want pesticide-free and organic food attributes. The literature review and survey results suggested how policies can break the status quo of intensive agriculture predominance. Thus, we propose a market–society–policy nexus to promote sustainable agriculture. Our suggestions are: (1) Policies should support sustainable agricultural systems at the landscape level to safeguard the ecological processes involved in agricultural production. (2) Markets should standardize eco-labels, improve clarity in foodstuff information, and relate environmental benefits to consumer benefits. (3) A subsidy on sustainable food is needed to keep the regular market prices and attract new consumers, at least in the early stages.

Unique plant functional traits (morpho-physio-anatomical) may respond to novel environmental conditions to counterbalance elevated carbon dioxide (eCO₂) concentrations. Utilizing CO₂, plants produce photoassimilates (carbohydrates). A mechanistic understanding of partitioning and translocation of carbon/photoassimilates into different plant parts and soils under ambient and eCO₂ is required. In this study, we examine and present the intrinsic relationship between plant functional traits and eCO₂ and seek answers to (i) how do plant functional traits (morpho-physio-anatomical features) affect C storage and partitioning under ambient and eCO₂ in different plant parts? (ii) How do plant functional traits influence C transfer to the soil and rhizosphere services? Our study suggests that morpho-physio-anatomical features are interlinked, and under eCO₂, plant functional traits influence the quantity of C accumulation inside the plant biomass, its potential translocation to different plant parts, and to the soil. The availability of additional photoassimilates aids in increasing the above- and belowground growth of plants. Moreover, plants may retain a predisposition to build thick leaves due to reduced specific leaf area, thicker palisade tissue, and higher palisade/sponge tissue thickness. eCO₂ and soil-available N can alter root anatomy, the release of metabolites, and root respiration, impacting potential carbon transfer to the soil.

Land use and land cover (LULC) change is a dynamic process influenced by various factors, including agricultural expansion. In Chile’s Aconcagua Basin, avocado plantations are potentially driving territorial transformations. However, current land cover data lacks the resolution required to accurately assess this impact. Accordingly, our study used advanced geospatial analysis techniques to address this gap. Through a detailed analysis of the spatial and temporal changes, it was determined that the most significant expansion of avocado plantations occurred between 2003 and 2013, with an increase of 402%. This growth primarily took place at the expense of native vegetation, particularly sclerophyllous shrubland, as well as other agricultural lands, near agricultural and urban lands. By 2023, changes in avocado plantation were significantly slower, with minimal alterations in LULC (5%), suggesting a possible influence of drought on small-scale farmers. However, the small loss of avocado plantation was mainly replaced by fruit farm land. Moreover, our findings suggest that while avocado plantations have become larger, more dominant, and more isolated, native vegetation has become more fragmented and reduced in patch size. Based on these results, sustainable land management practices were proposed. These findings provide a crucial foundation for developing sustainable land management strategies that balance agricultural production with environmental sustainability, landscape transformation and the well-being of local communities.

Soil amendments may decrease trace element accumulation in vegetables, improving food security and allowing the recovery of contaminated farmlands. Despite some promising results in the laboratory, validation of soil amendments in field conditions are scarce, especially in aerobic soils. Here, we assessed the effect of different potential soil amendments on arsenic (As) accumulation in lettuces. Then, we compared them in terms of food security and the associated investment (efficacy and efficiency, respectively). We also hypothesized that the soil amendments do not lead to side effects, such as yield decrease, phytotoxicity of Cu, or undesired changes in soil properties. Thereby, we assessed lettuces grown on untreated contaminated soils (C+), treated contaminated soils, and untreated uncontaminated soils (C−) in two contrasting soil types (sandy and loamy soils). The treated contaminated soils consisted of multiple soil amendments. Soil amendments were: diammonium phosphate (DP), iron sulfate (IS), ferrous phosphate (FP), calcium peroxide (CP), and organic matter (OM). We found that phosphate amendments (DP and FP) reduced the As in edible tissues of lettuce in both areas, while CP only reduced As accumulation in the sandy soils area. The As intake through lettuces grown on these amended soils was about 30% lower than on the unamended ones. Cu concentrations in lettuces above 25 mg kg⁻¹ grown in contaminated soils without reducing growth were found, a result that differed from non-field studies.