Ecopics_MX Monolith soil chemical analysis

ECOPICS Project : Monolith Soil Data In the field, after the extraction of the monolith and root and fauna collection , a composite soil sample ( ±500 g) was collected. Beside the monolith a soil cylinder (98.17 cm3) was extracted at a depth of 0.10 m, dried at 105 ° C and weighed to determine the bulk density (g /cm3). There were in total 83 samples. From each of these samples 100g were frozen (for nitrate and ammonium analysis), the rest were air dried and sieved at 2 mm for the rest of physicochemical analysis (% carbon,% hydrogen,% nitrogen and real density) the texture and the other chemical analysis described below were analyzed with the fresh sample. Ca, Mg, K, Na and cation exchange capacity (CEC, cmol / kg1) were determined by 1N ammonium acetate, pH7. Nitrate and ammonium were measured by extraction with potassium chloride solution and then by steam distillation with magnesium oxide and Dervada alliance. (Bremner, J. M., 1965) Available P was measured by Bray-Kurtz 1. Total P (mg / Kg) by wet digestion with nitric acid: perchloric acid 1: 2 and then quantified with sodium metavanadate. % P retained was measured by the Blackmore technique. Soil texture was measured using the pipette (Pleijsier, 1986). Soil particles were classified into size fractions: clay (0.002 m), silt (0.02mm), silt (0.05 mm), sand (&lt;0.25 mm), sand (&gt; 0.25 &lt;0.05mm) and sand (&gt; 0.5mm). The electrical conductivity in distilled water, a 1:5 ratio, is mixed and after 24 h it is measured with a Corning brand conductivity meter. The pH in water was in a 1:2 ratio. Humidity was determined using the oven technique at 105 ° C. The field capacity was determined in a pressure cooker at 0.33 Bar and then dried at 105 ° C. Organic matter and % organic C was determined by the Walker-Black technique. % C,% H and% N were determined by combustion (Dumas method) by the Perkin Elmer CHN 2400 analyzer.ECOPICS项目：整体土壤柱样品数据集。野外采样过程中，在采集整体土壤柱并完成根系与动物样本收集后，获取一份约500克的混合土壤样品；于该土壤柱旁0.10米深度处，采集体积为98.17 cm³的土芯，经105℃烘干称重以测定土壤容重（单位：g/cm³）。本数据集共计83份样品。每份样品取100g进行冷冻保存，用于硝态氮与铵态氮含量分析，剩余样品经风干后过2mm筛，用于其余理化分析，包括碳、氢、氮百分含量及真密度测定；土壤质地分析及下述其他化学指标检测则需使用鲜样开展。其中，钙（Ca）、镁（Mg）、钾（K）、钠（Na）及阳离子交换量（CEC, cmol/kg¹）采用1N乙酸铵（pH7）法测定；硝态氮与铵态氮通过氯化钾溶液浸提，随后经氧化镁蒸馏结合德瓦达合金法完成定量（Bremner, J. M., 1965）；有效磷采用Bray-Kurtz 1法测定；全磷（单位：mg/kg）采用硝酸-高氯酸（体积比1:2）湿法消解后，以偏钒酸钠法定量；土壤固持磷百分含量采用Blackmore法测定；土壤质地采用吸液管法（Pleijsier, 1986）测定，土壤颗粒分级为黏粒（0.002mm，原文笔误0.002m已修正）、粉粒（0.02mm）、粉粒（0.05mm）、砂粒（<0.25mm）、砂粒（0.05~0.25mm）及砂粒（>0.5mm）；水土比1:5的悬液经24小时静置后，使用康宁（Corning）品牌电导仪测定其电导率；水土比1:2的悬液用于测定水提pH值；土壤含水率采用105℃烘箱法测定；田间持水量通过压力釜法在0.33巴压力下测定，随后于105℃烘干称重；土壤有机质及有机碳百分含量采用Walker-Black法测定；碳、氢、氮百分含量则采用Perkin Elmer CHN 2400分析仪，通过燃烧法（杜马斯法，Dumas method）完成测定。