Abstract: In order to investigate the effect of cotton stalk biochar on retarding cadmium stress on the growth of rice (Oryza sativa L.), an outdoor pot experiment was conducted with ‘Tefengyou 2’ rice as test material. Adding cotton stalk biochar with concentrations of 0% (C0), 1% (C1), 2.5% (C2.5) and 5% (C5) into the paddy soil with cadmium concentration of 0, 1, 4, 8 mg·kg-1. The effects of application of biochar on plant height, leaf SPAD value, photosynthetic characteristics, leaf water use efficiency and other physiological and yield indexes were analyzed in rice jointing stage, booting stage, filling stage and ripening stage. The results showed that: ① under the condition of C0 treatment, cadmium stress treatment decreased plant height, leaf SPAD value, photosynthetic capacity, leaf water use efficiency and yield, and these indexes decreased with the increase of cadmium concentration (P<0.05). ② Under cadmium stress treatments, C1 treatment could significantly increase rice plant height, leaf water use efficiency and rice yield (P<0.05). Under four cadmium concentration of 0, 1, 4, 8 mg·kg-1, compared with C0, the yield per pot of C1 was increased by 45.45%, 30.63%, 22.20% and 12.98%, respectively. In general, cadmium had a stress effect on rice growth, reducing photosynthetic physiological capacity and yield of rice, however the application of 1% biochar can effectively retard cadmium stress on rice and increase rice yield.

Key words: cadmium stress, cotton stalk biochar, photosynthesis, yield, rice growth

摘要： 为探讨棉花秸秆生物质炭减缓镉对水稻（Oryza sativa L.）生长的胁迫影响，采用室外盆栽试验，以水稻品种‘特丰优2号’为试验材料，在镉浓度为0、1、4、8 mg·kg-1的稻田土壤中分别添加炭土质量比为0%（C0）、1%（C1）、2.5%（C2.5）和5%（C5）的棉花秸秆生物质炭，分析水稻拔节期、孕穗期、灌浆期和完熟期施用生物质炭对水稻株高、叶片SPAD值、光合特性、叶片水分利用率等生理及产量指标的影响。结果表明:①C0处理条件下，镉胁迫处理均使水稻株高、叶片SPAD值、光合能力、叶片水分利用率和产量降低，并随着镉浓度的增加，降低幅度增大。C1和C2.5处理显著提升了水稻叶片光合能力，C2.5处理的水稻叶片SPAD值较C1更高（P<0.05）。②镉胁迫处理下，与C0相比，C1处理可以显著提高水稻株高、叶片水分利用率，并使水稻增产（P<0.05）。在0、1、4、8 mg·kg-1四个镉浓度梯度下，与C0相比，C1处理的水稻产量分别增加45.45%、30.63%、22.20%和12.98%。综上，重金属镉对水稻生长具有胁迫效应，降低水稻光合能力及产量，施用1%生物质炭后可以有效减弱镉对水稻造成的胁迫，提高水稻产量。

关键词: 镉胁迫, 棉秆生物质炭, 光合能力, 产量, 水稻生长