施用生物炭对红壤富硒区硒生物有效性的影响

Effects of biochar application on selenium bioavailability in selenium-enrich red soils

研究生物炭调理措施对红壤区富硒土壤硒形态及硒生物有效性的影响,为富硒土壤硒活化及硒资源高效利用提供理论依据。通过盆栽试验,连续开展三批玉米苗期研究,设置3个生物炭添加水平:土壤质量0.5%(T1)、1.0%(T2)和1.5%(T3),以不添加生物炭处理为对照(CK),分析生物炭添加对土壤硒形态及玉米硒素营养的影响。结果表明:施用生物炭后,T1、T2和T3的可溶态硒分别平均提高0.46、0.42和0.43个百分点;可交换态硒分别平均提高0.61、1.66和1.50个百分点;降低了铁锰氧化物结合态硒的比例;有机结合态硒比例先降低后逐渐提高,残渣态硒比例则先提高后逐渐降低。玉米根系硒含量与土壤可溶态、可交换态及有效硒含量均呈显著线性正相关,玉米茎叶硒含量与土壤各硒形态之间的相关性不显著。施用生物炭能提高玉米植株体内的硒累积量,T1、T2和T3处理玉米植株平均硒累积量分别比CK提高9.46%、31.00%和21.22%。可见,在红壤上施用生物炭能有效提高土壤硒的生物有效性并促进硒在植物体内的累积,其中以添加土壤质量1.0%的生物炭效果最好。

The effects of biochar application on selenium forms and bioavailability in selenium-enrich soil in red soil region were studied,in order to provide a theoretical basis for selenium activation and efficient utilization of selenium resources in selenium-enriched soil.In this paper,a pot experiment was conducted with four biochar adding levels at 0.0%(CK),0.5%(T1),1.0%(T2) and 1.5%(T3) of soil weight.The effects of biochar addition on soil selenium forms and maize selenium nutrition were consecutively analyzed with three batches of maize seedlings.The results showed that the content of soluble selenium with T1,T2 and T3 was increased by 0.46,0.42 and 0.43 percentage on average,respectively;exchangeable selenium was increased by 0.61,1.66 and 1.50 percentage on average,respectively,after biochar application.The proportion of iron-manganese combined selenium was decreased,the proportion of organic matter-bond selenium was decreased and then increased gradually,while the proportion of residual selenium was increased and then decreased gradually.The selenium content of maize root was significantly positively correlated with the contents of soluble selenium,exchangeable selenium and available selenium of soil,while the selenium contents of maize stem and leaf were not related to the different forms of selenium in soil.Biochar application could increase the selenium accumulation in maize plants,and T1,T2 and T3 treatments were increased by 10.03%,31.30% and 21.21%,compared with CK,respectively.In conclusion,applying biochar can effectively improve the selenium bioavailable in red soil and promote the accumulation of selenium in plant,among them the effect of adding biochar at 1.0% of soil weight is the best.