Enhancing rice quality through tobacco–rice rotation cropping: Impacts on soil nutrients and cadmium reduction

Tobacco–rice rotation cropping (TRRC) can optimize the physical and chemical properties of the soil, improve soil fertility, and increase yields of tobacco (Nicotiana tabacum) and rice (Oryza sativa). However, there is a lack of attention to the quality of rice affected by TRRC. This study aims to investigate the effects of TRRC on rice quality and soil nutrient availability. Comparative analysis was conducted between TRRC and single-season rice (R mode) areas over 2 years, assessing rice quality metrics and soil nutrient profiles. The results indicated that rice quality significantly improved in TRRC areas, evidenced by an increase of 0.3%–1650% in metrics such as protein content and amylose content, with a notable reduction in cadmium (Cd) levels. Comparing with R mode, the content of organic matter and the available nitrogen (N) was respectively reduced 1.3%–73.3% and 3.8%–84.6% in soils of TRRC mode, while the content of available potassium (K) and available phosphorus (P) was respectively increased 4.0%–84% and 6.8%–95%. Pesticide residue detection of rice in TRRC area and R mode area meets the national pesticide residue standards for rice in China. These findings suggest that TRRC can optimize rice production and safety in Cd-contaminated regions.