生物炭早期植物毒性评估培养方法研究

为更加科学地评估生物炭潜在植物毒性,采用生物炭(B)、生物炭+土壤(B+S)、生物炭水浸提液+土壤(AE+S)、生物炭+石英砂(B+Q)、生物炭水浸提液+石英砂(AE+Q)5种不同的培养方法进行早期植物毒性效应实验。比较分析不同培养方法中西红柿种子发芽率、根长、芽长对生物炭的响应。结果表明:在5种培养方法中,随生物炭剂量增加,西红柿种子发芽率、根长、芽长呈现先增后降的变化趋势。虽在低剂量生物炭处理下(10.0 g·kg~(-1)),种子萌发表现出促进作用。但随剂量增加,除B+S和AE+S外,均表现出一定的抑制作用,且当剂量为160.0 g·kg~(-1)时,抑制作用达到最大。对比有土和无土培养方法中种子萌发情况发现,在高剂量下,无土培养方法中种子发芽率,根、芽生长所受抑制作用显著高于有土培养方法。无土方法中,尤其AE+Q方法中,高剂量生物炭对种子发芽率、根长、芽长表现出最大的抑制作用,其中发芽率抑制率为91.1%,根长抑制率为77.7%,芽长抑制率为93.7%。综合比较分析,生物炭水浸提液+石英砂(AE+Q)的培养方法干扰因子少,可提高毒性响应灵敏度。因此,在生物炭早期植物毒性效应评估中,该法可作为推荐的培养方法。

Investigations on Cultivation Methods for Assessing the Early Phytotoxicity of Biochar

In order to select a reasonable cultivation method for assessing the early phytotoxicity of biochar, 5 cultivation methods, including biochar only (B), biochar plus soil (B+S), aqueous extract of biochar plus soil (AE+S), biochar plus quartz sands (B+Q) and aqueous extract of biochar plus quartz sands (AE+Q), were investigated in this work. We evaluate the responses of germination rate, root length and shoot length of tomato seed to biochar dosage. Results indicated that almost similar responses of seed germination can be observed in these 5 methods, in which germination rate, root length and shoot length displayed an increase at lower dosages and a decrease at higher dosages. Although germination rate, root growth and shoot growth were all stimulated by biochar at low dosage (10.0 g?kg^-1), they were inhibited with increasing dosages (except for B+S and AE+S), and the maximum inhibition effects were observed at biochar dosage of 160.0 g?kg^-1. In contrast to the cultivation methods with soil, more significant inhibition on the germination rate, root growth and shoot growth can be observed at high biochar dosages in the soilless cultivation methods. Especially, the highest inhibition on germination rate, root length and shoot length were recorded as 91.1%, 77.7%, and 93.7% in AE+Q. Moreover, AE+Q method can be characterized by higher sensitivity, because some interferences from soil and biochar itself can be avoided greatly. Based on a comprehensive comparison, the aqueous extract of biochar plus quartz sands (AE+Q) can be recommended as a reasonable cultivation method for assessing the early phytotoxicity of biochar.