Effects of intercropping with native Pampa biome grasses on physiological responses of grapevines grown in soils contaminated with copper, manganese, and zinc

Intercropping grapevines with native grasses of the Pampa biome in soils contaminated with heavy metals such as copper (Cu), zinc (Zn), and manganese (Mn) may reduce the effects of their phytotoxicity to grapevines. The study aimed to evaluate how the intercropping of grapevines with Paspalum notatum and Paspalum plicatulum can reduce the toxicity potential of metals (Cu, Mn, and Zn) on the physiological, nutritional, and growth parameters of grapevines. The experiment was conducted in pots under greenhouse conditions using a completely randomized design with four replicates. The treatments consisted of a factorial combination of two soil contamination levels, defined according to the concentrations of Cu, Mn, and Zn: a low heavy metal level (−Metals) and a high heavy metal level (+Metals), and three cropping systems: grapevine monoculture, grapevine + P. notatum , and grapevine + P. plicatulum . The experiment lasted 190 days. Biomass production, nutrient concentrations in tissues, chlorophyll a fluorescence, leaf gas exchange, and root system biometrics were evaluated. At both soil metal contamination levels, intercropping reduced plant growth and grapevine root system biometrics compared with monoculture, indicating a negative effect on plant development. Despite this reduction, intercropping with P. notatum was more efficient in maintaining photosynthesis in grapevine leaves, regardless of the soil contamination levels. Intercropping of grapevines with native grasses reduced Cu, Mn, and Zn concentrations in grapevine organs. Native grasses may contribute to phytostabilization by reducing metal accumulation in grapevine tissues.