不同农林废弃物生物质炭对雷竹林酸化土壤的改良效果

摘要

以竹材边角料、 玉米Zea mays秸秆和山核桃Carya cathayensis蒲壳制备的生物质炭为材料,采集浙江省杭州市临安区集约经营模式下雷竹Phyllostachys violascens林酸化土壤进行90 d的黑麦草Lolium perenne盆栽试验,探究不同原料生物质炭添加对黑麦草生长及土壤养分、 酸度、 微生物丰度和酶活性的影响.结果表明:玉米秸秆炭和山核桃蒲壳炭显著提高了黑麦草生物量、 土壤有机碳质量分数、 全氮质量分数和pH值,而显著降低了土壤交换性氢和交换性铝的质量摩尔浓度(P<0.05);竹炭处理仅显著提高了土壤有机碳质量分数,降低了交换性氢质量摩尔浓度(P<0.05).相比对照,玉米秸秆炭可以显著提高真菌丰度,提高幅度为53％;而山核桃蒲壳炭和竹炭可以提高细菌丰度,提高幅度分别为71％和66％.相比玉米秸秆炭和竹炭,山核桃蒲壳炭可以更大程度地促进土壤脱氢酶、 β-葡萄糖苷酶、 纤维二糖苷酶和酸性磷酸酶活性.山核桃蒲壳炭和玉米秸秆炭处理下黑麦草生物量的提高主要归因于这2种生物质炭对土壤酸度、 养分、 微生物丰度和相关酶活性的改善作用.综合而言,山核桃蒲壳炭和玉米秸秆炭对雷竹林酸化土壤的化学性质和生物学性质具有较好的改良能力,而竹炭效果较差.图1表5参34%To evaluate the effects of biochars pyrolyzed from different feedstocks (bamboo, maize straw, and peels of Carya cathayensis) on the soil properties, acidity, microbial abundance, and soil enzyme activity in an acidic soil collected from a bamboo (Phyllostachys violascens) plantation in Lin'an, Zhejiang Province, a 90-day pot experiment was conducted in a completely randomized design with treatments of above three biochars and a non-amended control in three replicates. The biochars were added to the soil at a rate of 2％ (weight of biochar to soil) with ryegrasses being planted during the experiment. Fungal 18S rRNA and bacterial 16S rRNA gene abundances were assessed via quantitative real-time (qRT) polymerase chain reaction (PCR). Sig-nificant differences between treatment means were tested with one-way analysis of variance (ANOVA) followed by Duncan's test at P<0.05. Results indicated that biochars derived from maize and peels of C. cathayensis significantly (P<0.05) increased the biomass of ryegrass, soil organic carbon, total nitrogen, and pH, but de-creased (P<0.05) exchangeable H+ and exchangeable Al3+. Also bamboo biochar significantly increased (P<0.05) soil organic carbon and decreased (P<0.05) exchangeable H +. The qRT-PCR showed that compared with the control only additions of maize biochar significantly increased (P<0.05) fungal community abundance by 53％; whereas, peels of Carya cathayensis biochar and bamboo biochar significantly increased (P<0.05) bacterial community abundance by 71％ (C. cathayensis biochar) and 66％ (bamboo biochar). In comparison with maize straw biochar and bamboo biochar, the addition of peels of C. cathayensis biochar resulted in higher (P<0.05) enzymatic activities of dehydrogenase, β-glucosidase, β-D-cellobiosidase, and acid phosphatase. En-hancement of ryegrass growth was noted with peels of C. cathayensis biochar and maize straw biochar. In sum-mary, results indicated that biochars pyrolyzed from maize straw and peels of C. cathayensis showed better amelioration effects in terms of chemical and biological ability than bamboo biochar. [Ch, 1 fig. 5 tab. 34 ref.]