Search

Background and aims Halophytes possess the capacity to uptake high levels of salt through physiological processes and their root architecture. Here, we investigated whether halophyte/non-halophyte intercropping in saline soil decreases the soil salt content and contains root-dialogue. Methods Field and pot experiments were conducted to determine the plant biomasses and salt and nutrient distributions in three suaeda (Suaeda salsa) / maize (Zea mays L.) intercropping systems. The three treatments were set up by non-barrier, nylon barrier and plastic barrier between plant roots. Results The biomass of the non-barrier-treated maize was significantly lower than that of the nylon barrier-treated maize, whereas the suaeda root biomass showed a limited increase. The soil salt content negatively affected the non-barrier group’s roots compared with those in the nylon and plastic barrier-treated groups, and it was also higher on the maize side of the nylon-barrier treatment. There were higher available nitrogen and phosphorus contents in the soil of the non-barrier- and nylon barrier-treated groups compared with the plastic barrier-treated group. In addition, the pH was lower, and the available potassium content was higher, which suggested that rhizospheric processes occurred between the two species. Conclusions The suaeda/maize intercropping would decrease the soil salt content, and they also revealed potential rhizospheric effects though the role of root, which provides an effective way for the improvement of saline-alkali land.

Nitrogen (N) is the important nutrition that regulatory plant functioning and environmental stability of invasive plant species under flooding (F) conditions. Little information clarifies the role of nitrogen enrichment and flooding on the invasive plant functional traits and competition with native competitors. Plant functional traits play an essential role in the successful growth of plants under different environmental conditions. Therefore, greenhouse pots experiment was conducted with invasive plant species (Wedelia trilobata, WT), and its native competitor (Wedelia chinensis, WC) in monoculture and cocultivation culture, along with flooding and nitrogen enrichment conditions. Considering the impact of flooding (F) and nitrogen (N) on an individual basis, the plant physiological traits of WC were nonsignificant compared to that of WT. However, in the combination of flooding × additional nitrogen (F.N, F.2N), plant physiological traits of WT were comparatively higher than those of WC, especially in cocultivation. In flooding × additional nitrogen (F.N and F.2N), better phenotypic plasticity at different plant traits makes WT more dominant in resource competition over WC. In conclusion, improved functional traits of WT under nitrogen enrichment and flooding conditions enhanced its competitiveness over native competitors.