Vermicompost derived from mushroom residues improve soil C / P cycling, bacterial community and fungal abundance (soil properties / soil enzyme activities)

Soil pH was determined in a 1: 2.5 soil/water suspension by a digital pH meter (pH 700 Bench Meter, Eutech Instruments). Soil organic C (SOC) was determined by chemical oxidation using a K2Cr2O7 solution. Soil total C (TC) and total N (TN) were determined via combustion of ground subsamples (passed through a 0.16 mm mesh) using an automatic elemental analyzer (Analyzer vario MICRO cube, Elementar, German). Soil total P (TP) was determined by digestion with perchloric acid (HClO4). Available P (AP) was extracted with 0.5 M NaHCO3. The available potassium (AK) was determined by flame photometer using method described. We selected several representative soil enzymes involved in C、N and P cycling process, respectively. Potential activities of these soil enzymes are often related to biogeochemical transformation process in soilare often related to microbial metabolic rate and biogeochemical process in soil, so they are often used as indicators for soil microbial nutrient status. Soil C-cycling enzymes included α-D-glucosidase (AG, EC 3.2.1.20) and β-D-glucosidase (BG, E.C.3.2.1.21), N-cycling enzyme was β-N-acetylglucosaminidase (NAGase, EC 3.2.1.30 ). P-cycling enzyme included acid phosphomonoesterase (AcP, EC 3.1.3.2) and alkaline phosphomonoesterase (AIP, EC 3.1.3.1). We also selected dehydrogenase (DHA, intracellular enzyme, EC 1.1.1 ) to represent soil microbial activity. The activity of soil DHA was determined by colorimetric method (485 nm) after cultural process at 37 ℃ for 24h using 2, 3, 5-chlorinated triphenyltetrazolated chloride (TTC) as substrate. The activities of soil AcP and AIP were determined as described by. In brief, soil AcP and AIP were assayed with a modified universalSoil pH was determined in a 1: 2.5 soil/water suspension by a digital pH meter (pH 700 Bench Meter, Eutech Instruments). Soil organic C (SOC) was determined by chemical oxidation using a K2Cr2O7 solution. Soil total C (TC) and total N (TN) were determined via combustion of ground subsamples (passed through a 0.16 mm mesh) using an automatic elemental analyzer (Analyzer vario MICRO cube, Elementar, German). Soil total P (TP) was determined by digestion with perchloric acid (HClO4). Available P (AP) was extracted with 0.5 M NaHCO3. The available potassium (AK) was determined by flame photometer using method described. We selected several representative soil enzymes involved in C、N and P cycling process, respectively. Potential activities of these soil enzymes are often related to biogeochemical transformation process in soil are often related to microbial metabolic rate and biogeochemical process in soil, so they are often used as indicators for soil microbial nutrient status. Soil C-cycling enzymes included α-D-glucosidase and β-D-glucosidase, N-cycling enzyme was β-N-acetylglucosaminidase. P-cycling enzyme included acid phosphomonoesterase and alkaline phosphomonoesterase. We also selected dehydrogenase to represent soil microbial activity. The activity of soil DHA was determined by colorimetric method (485 nm) after cultural process at 37 ℃ for 24h using 2, 3, 5-chlorinated triphenyltetrazolated chloride (TTC) as substrate. The activities of soil AcP and AIP were determined as described by. In brief, soil AcP and AIP were assayed with a modified universal buffer of pH 11.0 and 6.5, respectively, using p-nitrophenyl phosphate as the substrate. The activities of soil AG and BG were measured using flu- orogenic substrates, which including: (i) AG assayed with 4-methylumbelliferyl-α-D-glucopyranoside; (ii)BG assayed with 4- methylumbelliferyl-β-D-glucopyranoside. buffer of pH 11.0 and 6.5, respectively, using p-nitrophenyl phosphate as the substrate. The activities of soil AG and BG were measured using flu- orogenic substrates, which including: (i) AG assayed with 4-methylumbelliferyl-α-D-glucopyranoside; (ii)BG assayed with 4- methylumbelliferyl-β-D-glucopyranoside.

土壤pH值在1:2.5的土水悬浮液中，采用数字pH计（pH 700台式仪，Eutech Instruments公司）测定。土壤有机碳（SOC）采用重铬酸钾（K₂Cr₂O₇）溶液化学氧化法测定。土壤总碳（TC）和总氮（TN）通过研磨后过0.16mm筛的子样燃烧法，采用自动元素分析仪（vario MICRO cube型，Elementar公司，德国）测定。土壤总磷（TP）采用高氯酸（HClO₄）消解法测定。有效磷（AP）采用0.5 mol/L碳酸氢钠（NaHCO₃）提取法测定。有效钾（AK）采用火焰光度计法测定（方法同前述）。本研究选取了参与碳、氮、磷循环过程的若干代表性土壤酶。这些土壤酶的潜在活性常与土壤生物地球化学转化过程、微生物代谢速率相关，因此常被用作土壤微生物营养状态的指示指标。碳循环相关酶包括α-D-葡萄糖苷酶（AG，EC 3.2.1.20）和β-D-葡萄糖苷酶（BG，EC 3.2.1.21）；氮循环相关酶为β-N-乙酰葡萄糖胺酶（NAGase，EC 3.2.1.30）。磷循环相关酶包括酸性磷酸单酯酶（AcP，EC 3.1.3.2）和碱性磷酸单酯酶（AIP，EC 3.1.3.1）。本研究还选取脱氢酶（DHA，胞内酶，EC 1.1.1）作为土壤微生物活性的代表指标。土壤DHA活性测定以2,3,5-三苯基氯化四氮唑（TTC）为底物，37℃培养24小时后采用比色法（485 nm波长）检测。土壤AcP和AIP活性测定方法同前述。简而言之，AcP和AIP分别在pH 11.0和6.5的改良通用缓冲液中，以对硝基苯磷酸盐为底物进行测定。土壤AG和BG活性采用荧光底物测定，具体为：（i）AG以4-甲基伞形酮-α-D-吡喃葡萄糖苷为底物；（ii）BG以4-甲基伞形酮-β-D-吡喃葡萄糖苷为底物。简而言之，AcP和AIP分别在pH 11.0和6.5的改良通用缓冲液中，以对硝基苯磷酸盐为底物进行测定。土壤AG和BG活性采用荧光底物测定，具体为：（i）AG以4-甲基伞形酮-α-D-吡喃葡萄糖苷为底物；（ii）BG以4-甲基伞形酮-β-D-吡喃葡萄糖苷为底物。