Hyperaccumulator Solanum nigrum L. Intercropping Reduced Rice Cadmium Uptake under a High-Bed and Low-Ditch Planting System

Rakhwe Kama; Qingguang Ma; Farhan Nabi; Maimouna Aidara; Peiyi Huang; Zhencheng Li; Juxi He; Sekouna Diatta; Huashou Li

doi:10.3390/plants12234027

Hyperaccumulator Solanum nigrum L. Intercropping Reduced Rice Cadmium Uptake under a High-Bed and Low-Ditch Planting System

Plants (Basel). 2023 Nov 30;12(23):4027. doi: 10.3390/plants12234027.

Authors

Rakhwe Kama^{1

2}, Qingguang Ma^{1

2}, Farhan Nabi^{1

2}, Maimouna Aidara³, Peiyi Huang^{1

2}, Zhencheng Li^{1

2}, Juxi He^{1

2}, Sekouna Diatta³, Huashou Li^{1

2}

Affiliations

¹ Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
² Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, Shaoguan University, Shaoguan 512005, China.
³ Laboratory of Ecology, Faculty of Sciences and Technology, Cheikh Anta University of Dakar, Dakar 50005, Senegal.

Abstract

Anthropogenic activities have raised cadmium (Cd) concentrations in agricultural soil, emerging as a primary catalyst for the decline in crop yield. Intercropping of two or several plants is one technique among many Cd phytoremediation techniques that has gained enormous attention recently. However, the impact of cultivation modes on Cd movement in rice plants when intercropped with heavy metal (HM) hyperaccumulator plants remains unclear. Thus, this study was designed to explore the effects of cultivation modes and the intercropping of rice with Solanum nigrum L. on rice growth and Cd uptake in Cd-contaminated soil. The experimental design encompassed five treatments: dry cultivation of monocultured rice, monocultured Solanum nigrum L., and intercropped rice-Solanum nigrum L.; flood cultivation of monocultured rice; and intercropped rice-Solanum nigrum L. in a high-bed and low-ditch planting system. The results revealed a significant increase in rice growth when intercropped with Solanum nigrum L., with a notable increase of 18.32 g∙plant^-1 observed in rice biomass in dry cultivation under the intercropping system. In contrast, a more modest increase of 3.67 g∙plant^-1 was observed in the high-bed and low-ditch intercropped rice-Solanum nigrum L. mode. The soil total Cd was higher in dry cultivation of monocultured rice and Solanum nigrum L. compared to intercropped rice/Solanum nigrum L.-cultivated soil, with lower values recorded for intercropped rice/Solanum nigrum L. under the high-bed and low-ditch planting system. In contrast, no significant effect was noted on soil exchangeable Cd content based on the planting pattern and cultivation mode. Intercropping with Solanum nigrum L. demonstrated a significant reduction of Cd content in various rice tissues, particularly in roots at the maturity stage, while Cd content was reduced across all rice tissues under the high-bed and low-ditch planting system. The Cd content in the stem, leaves, and bran of monocropped rice was higher compared to intercropped rice. This study suggests that the rice-Solanum nigrum L. intercropping system effectively reduces rice Cd uptake, particularly under the high-bed and low-ditch planting system.

Keywords: Cd; Solanum nigrum L.; high-bed and low-ditch planting system; hyperaccumulator; intercropping system.

Abstract

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