活化铁尾砂与镁改性生物炭配施对水稻幼苗生长及盐碱土性质的影响

为探究活化的高硅型铁尾砂与镁改性生物炭配施材料对水稻幼苗生长及盐碱土壤理化性质的影响以及改善盐碱地水稻生产力的可行性，本研究应用电子扫描显微镜对生物炭材料进行形貌结构观察，应用傅里叶变换红外光谱仪对生物炭材料进行官能团表征；开展盆栽实验，探究活化铁尾砂与生物炭材料配施对水稻幼苗的形态学和生理学的影响及对盐碱土的改善效果。结果表明，相比于其他生物炭材料，活化铁尾砂-镁改性生物炭材料孔隙较大，表面更加粗糙，对于养分的吸附能力强，表面的官能团丰富。盆栽实验中活化铁尾砂-镁改性生物炭配施组中水稻幼苗株高、根长、根冠比和干质量分别较对照组提高12.61%、191.49%、42.93% 和 100.00%；叶片的丙二醛和活性氧含量分别降低 65.76% 和 46.46%；过氧化氢酶、超氧化物歧化酶、叶绿素和可溶性蛋白值分别升高117.35%、44.75%、55.00%和19.31%。施用活化铁尾砂-镁改性生物炭材料后，盐碱土的电导率降低，pH、总碳、总氮、土壤有效硅、总磷和总钾含量升高。研究证明活化铁尾砂-镁改性生物炭材料性能优越，并且活化铁尾砂与镁改性生物炭配施改善了盐碱土壤理化性质和养分含量，使水稻幼苗活性氧含量降低及抗氧化酶活性提升，减缓盐碱土对水稻幼苗生长的胁迫，促进盐碱土壤中水稻幼苗生理过程，增加干物质积累，可以促进盐碱地水稻幼苗生长。

Effects of a combination of activated iron tailings and magnesium-modified biochar on rice seedling growth and properties of saline-alkali soil

This study aimed to investigate the effects of activated iron tailings and magnesium-modified biochar materials on rice seedling growth and soil properties, as well as to assess the viability of improving rice production in saline-alkaline soil. A scanning electron microscope was used to characterize the morphology and structure of the biochar materials, and Fourier transform infrared spectrometry was applied to determine the functional group composition of the magnesium-modified biochar materials. Pot tests were undertaken to investigate the morphological impacts of activated iron tailings and biochar materials, the physiological traits of rice seedlings, and the effects on saline-alkali soil. Compared with other biochar materials, our results suggested that activated iron tailings and biochar treated with magnesium had more surface functional groups, larger pores, and a rougher surface. Pot experiments demonstrated that plant height, root length, root-shoot ratio, and dry weight of rice seedlings after applying the activated iron tailing-magnesium-modified biochar increased by 12.61%, 191.49%, 42.93%, and 100.00% respectively, in comparison to the control group. Malondialdehyde and active oxygen concentrations in leaves decreased by 65.76% and 46.46%, respectively. Catalase and superoxide dismutase activities, and chlorophyll and soluble protein levels, increased by 117.35%, 44.75%, 55.00%, and 19.31%, respectively. After applying iron tailingsmagnesium-modified biochar, the electric conductivity of saline-alkali soil was reduced, while pH, total carbon, total nitrogen, total phosphorus, soil available silicon, and total potassium contents increased. These results indicate that activated iron tailings and magnesium modified biochar have great potential, and their application can enhance the physical and chemical properties and nutritional content of saline-alkaline soil, reduce the active oxygen content of rice seedlings, increase the activity of antioxidant enzymes, and mitigate the stress of saline soils on the growth of rice seedlings. Moreover, rice seedling growth in saline-alkaline soil can be promoted by increasing the accumulation of dry matter.