College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China.
Chemosphere. 2018 May;199:417-426. doi: 10.1016/j.chemosphere.2018.02.007. Epub 2018 Feb 5.
To exploit the plant byproducts from selenium (Se) biofortification and reduce environmental risk of inorganic Se fertilizer, pot experiment was conducted in this study. The effects of Se-enriched wheat (Triticum aestivum L.) straw (WS + Se) and pak choi (Brassica chinensis L.) (P + Se) amendment on organo-selenium speciation transformation in soil and its bioavailability was evaluated by pak choi uptake. The Se contents of the cultivated pak choi in treatments amended with the same amount of Se-enriched wheat straw and pak choi were 1.7 and 9.7 times in the shoots and 2.3 and 6.3 times in the roots compared with control treatment. Soil respiration rate was significantly increased after all organic material amendment in soil (p < 0.05), which accelerated the mineralization of organic materials and thus resulted in soluble Se (SOL-Se), exchangeable Se (EX-Se), and fulvic acid-bound Se (FA-Se) fraction increasing by 25.2-29.2%, 9-13.8%, and 4.92-8.28%, respectively. In addition, both Pearson correlation and cluster analysis showed that EX-Se and FA-Se were better indicators for soil Se availability in organic material amendment soils. The Marquardt-Levenberg Model well described the dynamic kinetics of FA-Se content after Se-enriched organic material amendment in soil mainly because of the mineralization of organic carbon and organo-selenium. The utilization of Se in P + Se treatment was significantly higher than those in WS + Se treatment because of the different mineralization rates and the amount of FA-Se in soil. Se-enriched organic materials amendment can not only increase the availability of selenium in soil but also avoid the waste of valuable Se source.
为了利用硒（Se）生物强化的植物副产物并降低无机 Se 肥料的环境风险，本研究进行了盆栽实验。通过小白菜（Brassica chinensis L.）吸收评估了富硒小麦（Triticum aestivum L.）秸秆（WS+Se）和小白菜（P+Se）添加对土壤中有机硒形态转化及其生物有效性的影响。与对照处理相比，用等量富硒小麦秸秆和小白菜处理的栽培小白菜中硒含量在地上部增加了 1.7 倍，在根部增加了 2.3 倍，在地上部增加了 9.7 倍，在根部增加了 6.3 倍。所有有机物质添加到土壤中后，土壤呼吸速率显著增加（p<0.05），这加速了有机物质的矿化，从而导致可溶硒（SOL-Se）、可交换硒（EX-Se）和富啡酸结合硒（FA-Se）分别增加了 25.2-29.2%、9-13.8%和 4.92-8.28%。此外，皮尔逊相关和聚类分析均表明，EX-Se 和 FA-Se 是有机物质添加土壤中土壤 Se 有效性的更好指标。Marquardt-Levenberg 模型很好地描述了富硒有机物质添加到土壤后 FA-Se 含量的动态动力学，主要是由于有机碳和有机硒的矿化。由于矿化率和土壤中 FA-Se 的含量不同，P+Se 处理中的 Se 利用率明显高于 WS+Se 处理。富硒有机物质添加不仅可以增加土壤中硒的有效性，还可以避免宝贵的硒源的浪费。
