The synergistic effect between heavy metals and microplastics can affect soil properties as well as plant performance and yield. The objective of this study was to evaluate the combined effect of microplastics and cadmium on a soil–plant system. Specifically, we proposed to explore changes in soil microbiological activity, the growth and yield parameters of strawberry plants, and to evaluate the accumulation of these pollutants in the soil and root system. Plants were planted in clay pots under greenhouse conditions. The experiment was set up as a completely randomized design, with four treatments (Control; MPs; Cd; and Cd + MPs) and five replicates. The results showed that MPs and/or Cd affected plant growth, plant biomass, the number of fruits, root characteristics, dehydrogenase activity, acid phosphatase, and microbial biomass, and increased the accumulation of Cd in the roots and soil. The increased bioavailability of Cd, due to the presence of microplastics, could explain the observed negative effects on soil properties and the performance of strawberry plants.

There is a worldwide increase of heavy metal or potentially toxic element (PTE), contamination in agricultural soils caused mainly by human and industrial action, which leads to food contamination in crops such as in maize. Cadmium (Cd) is a PTE often found in soils and it is ingested through food. It is necessary to determine the bioabsorption, distribution, and accumulation levels in maize to reduce or prevent food chain contamination. Cadmium absorption and accumulation in three maize cultivars were evaluated in three agricultural environments in Chile by increasing CdCl₂ rates (0, 1, and 2 mg·kg⁻¹). Evaluation included Cd accumulation and distribution in different plant tissues, bioaccumulation factor (BAF), bioconcentration factor (BCF), translocation factor (TF), and tolerance index (TI). Cadmium whole-plant uptake was only affected by the CdCl₂ rate; the highest uptake was obtained with 2 mg·kg⁻¹ CdCl₂ (34.4 g·ha⁻¹) (p < 0.05). Cadmium distribution in the maize plant usually exhibited the highest accumulation in the straw (p < 0.05), independently of the environment, Cd rate, and evaluated cultivar. Given the results for TF (TF > 2) and BAF (BAF > 1), the Los Tilos and Chillán environments were classified as having a high capacity to contaminate the food chain for all evaluated cultivars.

Blueberry (Vaccinium corymbosum L.) production under tunnels has spread in recent years. However, there is little information on the productive and physiological responses of blueberry grown under high tunnels. The objective of this research was to evaluate the effect of high tunnel microclimate on the physiological and productive responses of blueberries. A total of 1296 plants of highbush blueberry 'O'Neal' were grown in high tunnels, leaving the same amount of plants under open fields (control). Environmental temperature (T, °C) and relative humidity (RH, %), diffuse and total photosynthetically active radiation (PAR diffuse and PAR total , µmol m-2 s-1), stomatal conductance (g s , mmol m-2 s-1) and maximum photochemical efficiency of photosystem II (F v /F m) of the leaf were measured. Fruit yield, date of harvest initiation and fruit growth rate were also determined. The maximum T was on average 10-12 °C higher inside the high tunnel than the control, whereas the minimum T averaged only 2-5 °C higher. PAR total decreased an average of 25% under tunnel, while levels of PAR diffuse increased more than 150%. The g s ranged between 42% and 99% higher in the high tunnel compared to the control, and was positive and statistically related (r 2 = 0.69**) to PAR diffuse variations. Blueberries under high tunnel recorded an accumulated yield 44% higher, while harvest started 14 d earlier compared to control. The results suggest that high tunnels in blueberries increases fruit yield and improves precocity due to higher temperatures during the flowering stage and fruit set. Particular light conditions under tunnels would favor higher leaf stomatal conductance in this crop.

Different concentrations of compost applied as organic fertilizer can modify productive, quality, and chemical parameters in several fruit tree species. The objective of this study was to determine the effect of increasing applications of compost on physiological, productive, and quality parameters in calafate fruit during the seasons of 2018–2019 and 2019–2020. The study was conducted on a commercial calafate orchard using a randomized complete block design with four treatments (CK: no compost application, T1: 5 Ton ha⁻¹, T2: 10 Ton ha⁻¹, and T3: 15 Ton ha⁻¹), each with four repetitions. The results did not show statistical significance for stomatal conductance (Gs), quantum yield of PSII, or photosynthetic active radiation (PAR) within treatments. As for fruit yield, a statistical difference was found between the control treatment and T1, which were lower than T2 and T3 in both seasons. The trees reached a higher leaf area index with T2 in both seasons. The highest antioxidant capacity was obtained with T3 and T2 for the first and second season, respectively. Polyphenols and total anthocyanin production showed statistical significance, with a higher content at the second season with T2. It is concluded that the dose under which yield, quality, and nutraceutical content of calafate fruit are optimized is the one used in T2, 10 Ton ha⁻¹.

The increasing use of soils for agricultural purposes can expose some species that are important in the human diet, such as durum wheat (Triticum turgidum L. Var durum), to absorb cadmium (Cd) in soils with high concentrations of this metal, with subsequent risk in the human health. The development of genotypes with low Cd accumulation, as well as the study of field conditions of different cultivar combinations, Cd soil concentrations, and environments, can contribute in generating foods with low Cd accumulation. Field experiments were conducted in different agricultural zones in Chile (La Serena, Los Tilos, Chillán, and Temuco) with three durum wheat cultivars in soils where three increasing Cd rates were applied. Results indicated that applying Cd to the soil did not affect yield or biomass production in the plant. Cadmium accumulation in grains, straw, and roots was significantly affected by increasing Cd rates. Cadmium distribution in the plant was lower in the grains and straw and higher in the roots. Cadmium apparent recovery was lower than 0.8%, and it was not affected by the rate of soil Cd. All the evaluated parameters were influenced by the study location, and only some showed differences among cultivars. Of the three evaluated cultivars, only ‘Lleuque-INIA’ exhibited a Cd concentration that was lower than internationally characterized genotypes described as low Cd accumulators.