【摘 要】
：
Cropland productivity has been signiifcantly impacted by soil acidiifcation resulted from nitrogen (N) fertilization, especialy as a result of excess ammoniacal
【机 构】
：
Fengqiu Agro-Ecological Experimental Station,Key Laboratory of Reservoir Aquatic Environment
论文部分内容阅读
Cropland productivity has been signiifcantly impacted by soil acidiifcation resulted from nitrogen (N) fertilization, especialy as a result of excess ammoniacal N input. With decades’ intensive agricultural cultivation and heavy chemical N input in the Huang-Huai-Hai Plain, the impact extent of induced proton input on soil pH in the long term was not yet clear. In this study, acidiifcation rates of different soil layers in the soil proifle (0–120 cm) were calculated by pH buffer capacity (pHBC) and net input of protons due to chemical N incorporation. Topsoil (0–20 cm) pH changes of a long-term fertilization ifeld (from 1989) were determined to validate the predicted values. The results showed that the acid and alkali buffer capacities varied signiifcantly in the soil proifle, averaged 692 and 39.8 mmolc kg–1 pH–1, respectively. A signiifcant (P
其他文献
目的 研究维持性血液透析(MHD)患者透析中低血压(IDH)发生的危险因素,分析血氨基末端脑钠肽前体( NT-proBNP)水平与IDH发病的关系,为防治提供依据.方法 收集2009年3月至5月我
目的建立绝经期泌尿系感染动物模型。方法对小鼠进行去势和尿路感染处理,通过阴道细胞学涂片、阴道细胞角化指数、小鼠血清E2水平和去势小鼠膀胱细菌培养和膀胱病理分级对尿
在共和国的版图中，近10年来很少有哪个区县区能像沈阳铁西这样吸引如此多的目光，其大落大起几乎浓缩了一部中国现代工业史。
推进节能减排、发展低碳经济，既是转变经济发展方式的当务之急，更是确保经济社会可持续发展的长远之举和战略选择。几年前，节能减排作为约束性指标首次写入中国“十一五”规划，明
2012年春节期间，江苏移动公司不同地区的SGSN（GPRS服务支持节点）网元负荷指标呈现不同的变化趋势。不同地区GPRS（通用分组无线业务）的春节话务量变化，与不同地区经济发展水平和发展
拥有沈抚新城最大的54000平方米厂房的美程在线,厂房已经全部建设完成,如今的沈抚新城产业区已经完成20平方公里的开发,有将近300个项目在这里落户,多数是在行业领域具有领先
Eight compounds were isolated from the fermentation cultures of rice sheath blight pathogenRhizoctonia solaniKühn. They were identiifed as ergosterol (1), 6β-
MicroRNAs (miRNAs) are ~21 nucleotide (nt), endogenous RNAs that regulate gene expression in plants. Increasing evidence suggests that miRNAs play an important
The objectives of this study were to estimate genetic parameters of lactation average somatic cel scores (LSCS) and examine genetic associations between LSCS an
abstract Starch is the major carbohydrate in oat (Avena sativaL.) and starch formation requires the coordinated actions of several synthesis enzymes. In this st