三峡库区忠县-万州多目标调查土壤地球化学特征分析

通过对＂三峡库区响水滩等7幅1∶5万区域地质多目标调查＂取得的土壤元素进行分析统计,对比国内土壤元素和重庆沿江土壤元素含量数据,结果表明：调查区大多数元素含量处于正常水平,而Cd、Zr元素含量较高,Mo、Br、I偏低;通过对54项元素及指标相关性分析,发现部分元素如Sc-V、Fe-Ga、Nb-Ti、Sr-Na、Br-I、F-Li等元素对具有较强的相关性,而Ag、Au、Hg等较为分散;通过对每个地层的元素含量统计揭示出各种元素在各个地层单元中的分布特征。     

内蒙古河套农业经济区玉米产区生态地球化学特征研究

[目的]研究河套农业经济区玉米产区生态地球化学特征.[方法]通过采集研究区玉米根系土及玉米各部位样品,分析了根系土和玉米各部位地球化学特征.[结果]灌淤土中大部分元素含量相对较高;大多数元素在玉米的茎叶中相对富集;F、Mn、Co元素在根中相对富集;N元素在籽实中强烈富集,Zn、F在籽实中相对较富集.[结论]建议河套地区富F的土壤环境中要采用低F化肥.玉米种植区均需要增加氮肥.对化肥中的各有害元素需进行控制.     

内蒙古河套农业经济区玉米产区生态地球化学特征

[目的]研究河套农业经济区玉米产区生态地球化学特征。[方法]通过采集河套农业经济区玉米根系土及玉米各部位样品,分析了不同土壤类型根系土及玉米各部位的微量元素含量。[结果]灌淤土中大部分元素含量相对较高;大多数元素在玉米的茎叶中相对富集;F、Mn、Co元素在根中相对富集;N元素在子实中强烈富集,Zn、F在子实中相对较富集。[结论]建议河套地区玉米种植区在今后生产中应该合理施肥,控制化肥中有害元素的施入。     

地球化学工程技术修复农田土壤重金属污染研究进展

随着我国农田土壤重金属污染的加剧,传统的物理、化学和生物修复方法不能完全满足农田土壤修复的要求,亟待寻找高效稳定、成本低廉且无二次污染的农田土壤修复技术。地球化学工程技术即是遵循这一理念的修复技术之一。本文就地球化学工程技术在农田土壤修复中的应用现状与阶段性成果进行了回顾,着重概述了地球化学材料固定与钝化,地球化学工程阻隔,地球化学转化、吸收与浓集以及地球化学自然降解与衰减等4类技术在土壤修复中的研究进展和实践成果。并在此基础上讨论了应用地球化学工程技术进行农田土壤修复的优势和不足,展望了地球化学工程技术修复农田土壤的应用前景和发展趋势,提出注重多种修复技术的联合使用、开发功能化纳米材料与磁性纳米复合材料进行修复及加快土壤修复理论成果转化的研究方向。     

天山及其邻近地区土壤某些元素的地球化学分异初探

本文在３４个土壤剖面１８１个样品大量元素和３６个剖面１７６个样品的Ｚｎ，Ｎｉ，Ｃｕ，Ｃｏ，Ｖ等微量元素分析资料的基础上，讨论了天山及其邻近地区土壤成土的地球化学过程，这些元素的空间分异。认为天山及其邻近地区土壤的形成存在着三个主要的成土地球化学过程，即脱盐基过程，镁，钙积过程，钠积过程；随海拔高度的降低，水分减少，温度升高，元素的空间分异表现为：盐基自高山淋溶后，朝着盆地方向，按它们的盐类溶解度大     

粤西地区土壤-植物系统中稀土元素地球化学特征

在广东省西部不同地区采取土壤、植物样品，并对其中的稀土元素含量采用ICP-MS法测定，研究了稀土元素在土壤、植物叶中的地球化学特征。结果表明：土壤一植物系统的各环节间稀土元素的含量模式基本相似。不同母岩发育的土壤稀土分布有较大的差异，其中以花岗岩发育的土壤稀土含量最高。在土壤的各个剖面层中，心土层和底土层稀土含量高于表土层，轻重稀土发生分异，均有不同程度的Eu亏损，Ce表现为土壤各层位中的正异常。同一采样点的不同种属植物具有相似的稀土分配模式，在不同母岩发育土壤上生存的同一种属植物稀土分配模式不同，其稀土分布均受其所生存土壤的影响和制约，同时具有自身的生物地球化学特性。生物吸收系数表明植物对稀土元素的吸收能力的差异，稀土元素在由土壤向植物体运输迁移中发生了明显的分馏作用，重稀士相对贫乏。     

湖南张家界典型植烟土壤地球化学特征研究

为了研究张家界山地植烟区域土壤的成土环境及地球化学元素的丰缺状况和迁移富集规律,为烟区优质特色烟叶的生产和布局提供科学依据,本文采集23个长期耕种的典型植烟土壤剖面样品,测定分析了25种地球化学元素(氧化物)的含量,并对土壤的风化发育状况和元素(氧化物)的迁移富集特征进行了研究。结果表明,张家界烟区主要成土母质如石灰岩、板页岩、紫色砂页岩风化物均受到了较强的风化作用,化学风化指数(CIA)介于73.19～88.03之间,总体上土壤具有Ca、Na贫乏而Fe、Al相对富集的化学组成特征。其中紫色砂页岩风化物发育形成的紫色土的风化作用较强,土壤的淋溶作用较强;石灰岩风化物发育形成的土壤富铝化程度较低。黄壤、水稻土、紫色土中地球化学元素多数表现出一定的富集特征,大量有益营养元素的富集对于提高烟叶产量具有重要作用。土壤剖面淋溶层中元素(氧化物)P、B、Se、Mn、Zn、Cu、Ni、Y、Sc、La、Fe2O3、SiO2的含量均高于中国或世界土壤元素(氧化物)中值(均值),而N、S、Cl、Mo、Co、Sr、Br、I、CaO、MgO、K2O、Na2O、Al2O3的含量偏低,其中元素(氧化物)N、P、S、Mo、Se、Mn、Zn、Br、I、CaO、MgO在土壤剖面中的含量变化较大。通过对元素(氧化物)富集系数的聚类分析,将元素(氧化物)分为3类:呈较强富集特征的元素N、P、S、Se;呈较强迁移特征的元素(氧化物)Br、I、Mn、CaO;变化较稳定的其他元素。微量元素B、Zn、Cu和稀土元素Y、Sc、La含量较丰富且变化相对稳定,表明除了常量元素N、P、S以外,微量元素Se、B、Zn、Cu和稀土元素Y、Sc、La可能是影响张家界烟区烤烟品质的重要特征元素。     

Soil carbon pools under long-term rice-wheat cropping system in Inceptisols of Indian Himalayas

Knowledge about soil organic carbon (SOC) stock and its allocation into different pools is important for global food and environmental security. Accordingly, an attempt is made in the present study to investigate into the dynamics of SOC pools i.e. total soil organic carbon (TOC), oxidisable organic carbon (OC) and its different fractions viz. very labile (C_VL), labile (C_L), less labile (C_LL) and non-labile (C_NL) in soils under a 26 years old long-term experiment with rice (Oryza sativa L) – wheat (Triticum aestivum L) cropping system on Inceptisols under humid agro-climatic region of India with different soil management practices (control, 100% recommended dose of NPK, and 50% recommended dose of NPK + 50% N through farmyard manure (FYM). Of the several pools analyzed, a higher proportion of C was found in labile pool followed by very labile, non-labile, and less labile ones constituting about 46, 26.5, 20 and 7.3% of the total organic C at surface soil. The NPK+FYM treatment was found to have higher SOC pools, lability index (LI), recalcitrance indices and stratification ratio as compared to others. Results indicated that balanced fertilization with inorganic and organics is important for maintaining overall sustainability of the rice-wheat system.     

Effect of Graded Levels of Surface Crop Residue Application Under Minimum Tillage on Carbon Pools and Carbon Lability Index in Sorghum (Sorghum bicolor (L.) Moench)-Cowpea (Vigna unguiculata) System in Rainfed Alfisols

A long term experiment (2005–2012) was conducted in rainfed semi-arid tropical Alfisol at Hayathnagar Research Farm of Central Research Institute for Dryland Agriculture, Hyderabad, India. The aim of this experiment was to study the long-term impacts of graded levels of surface crop residue application on carbon (C) pools, aggregate associated C, C lability index and their relationship with crop yield. The experiment was conducted in a randomized block design (RBD) with minimum tillage (MT). Experimental treatments comprised of four levels of surface application of sorghum crop residues (@ 0, 2, 4 and 6 t ha^?1). The test crops, sorghum and cowpea, were grown in rotation yearly. Based on the pooled analysis of long term data (2005–2012), the study revealed that the surface application of sorghum residue @ 6 t ha^?1 and 4 t ha^?1 recorded 21% and 16% higher sorghum grain yields, respectively over control (no residue) whereas, the corresponding increase in the cowpea yield was 50% and 60%, respectively. Besides, the concentrations of soil organic carbon (SOC), inorganic carbon (IC), total carbon (TC), particulate organic carbon (POC) in the top surface soil (upper layer, 0–5cm depth) were found significantly higher than the sub-surface soil (lower layers, 5–15 cm depth) in all the treatments. Storage of soil C was assessed in soil aggregates fractions, and it was found that the smaller size aggregate fractions (0.053mm) contained significantly (p = 0.05) higher content of SOC compared to the large sized fractions (2 mm). The amount of very labile fraction of C extracted with 12 N H₂SO₄ was significantly higher (1.04 g kg^?1) with the application of sorghum stover @ 6t ha-¹ compared to other residue level treatments, in the 0-5 cm soil layer. The Lability Index (LI) increased with the increase in the amount of residues applied and was significantly higher in the surface soils compared to subsurface soil. The results of this study will be highly relevant and of significant value from the view point of managing SOC and its different pools in soil under abiotically stressed semiarid tropical Alfisols soils.     

国家地理标志伍家台贡茶的生态农业地质环境研究

历史名茶伍家台贡茶,是国家地理标志产品、国家地理标志商标、国家农产品地理标志。其原产地宣恩县万寨乡,位于新阶段扶贫攻坚主战场武陵山片区。农业地质学是地质科学与农业科学相结合衍生的边缘学科。介绍了伍家台农业地质环境条件,探讨了生态农业地质环境的地球化学特征。