佳县郑家沟流域土地资源评价

本文主要论述佳县郑家沟流域土地类型、土地生产力分级和土地利用评价等问题。根据土地的性质、土地的适宜性和限制性,建立了土地利用评价系统。研究结果指出,由于流域土地利用不合理,管理措施不当,土壤侵蚀和土地沙化严重,土壤瘠薄,农业生产水平很低。调整土地利用结构,培肥地力,造林种草,是开发该区土地资源,提高土地生产能力,改善生态环境的主要途径。     

佳县郑家沟流域土地资源评价

本文主要论述佳县郑家沟流域土地类型、土地生产力分级和土地利用评价等问题。根据土地的性质、土地的适宜性和限制性,建立了土地利用评价系统。研究结果指出,由于流域土地利用不合理,管理措施不当,土壤侵蚀和土地沙化严重,土壤瘠薄,农业生产水平很低。调整土地利用结构,培肥地力,造林种草,是开发该区土地资源,提高土地生产能力,改善生态环境的主要途径。     

中国土地资源的土壤侵蚀状况分析

土壤侵蚀不仅会导致土地资源的退化 ,而且会造成环境恶化。在定义土壤侵蚀指数的基础上 ,以土地资源类型为单元 ,以遥感与 GIS技术为支撑 ,分析不同土地资源类型下土壤侵蚀类型与强度 ,阐明土地资源的土壤侵蚀背景 ,揭示出两者之间的关系 ,并作出区域上的分析。在我国的北方以还草为主 ,南方以还林为主。     

土壤系统分类中土壤水热状况的确定方法及应用研究——以山西省为例

土壤温度和水分状况作为表征土壤特性的重要参数,在土壤系统分类中是某些分类单元划分的重要依据。而现有的土壤水热状况估算方法存在数据不易获取、计算过程复杂等问题,在野外土壤调查及土壤系统分类工作中的适用性不强。本文提出一个基于气象数据的土壤水热状况快速估算方法,并结合山西省实地调查的75个剖面数据,对其在土壤系统分类中的应用进行探讨,以期为区域野外土壤调查及土壤系统分类工作提供借鉴和参考。结果表明:1基于气象数据的土壤温度估算方法在山西地区具有较好的适用性,其估算结果能代替土壤温度实测值来研究该区域的土壤温度状况;2基于气象数据的土壤水分状况估算结果仅适用于不受地下水影响的地带性土壤水分状况的确定,而对于受地下水影响的区域需根据土壤所处的实际水分环境状况进行分析和判定;3土壤水热状况在中国土壤系统分类中的分选性强,在野外土壤调查及土壤系统分类时,应特别注意区域土壤水热状况的差别。     

四川省土壤水分状况空间分布特征

土壤水分状况(SMR)是确定土壤分类单元的重要依据,也是土壤资源可持续利用的保证。基于1951—1980年四川省160个气象站的地面气候资料,利用FAO-56 Penman-Monteith公式和FAO-PPP-17 Penman修正公式计算各个站点年/月潜在蒸散量和干燥度(IA),采用地统计学原理与普通Kriging法对年/月IA进行空间插值,依据《中国土壤系统分类检索(第三版)》中有关SMR的规定,对四川省可能的SMR空间分布特征进行分析。结果表明:四川省SMR区域差异明显,整体呈现\"东湿西干\"的空间分布特征;以\"湿润\"和\"半干润\"为主,湿润主要分布于四川盆地,\"半干润\"主要分布在川西南山地及川西北高山高原地区;\"常湿润\"分布在宜宾部分区域,川西北德荣南部为\"干旱\"。本研究为四川省土壤系统分类与土壤资源的可持续利用提供了科学依据。     

The use of inverse modelling and dipwell data in the calibration and evaluation of a soil water simulation model

The soil water regime is a key component of the current UK land evaluation systems. However, direct quantification requires many years of measurements which are not available for large parts of the country. One method for extending existing data is through the use of soil water simulation models. A physically based, one-dimensional soil water simulation model (SOIL) was calibrated against relatively easily obtained dipwell, soil water retention and saturated hydraulic conductivity data for eight relatively level sites in Scotland with limited potential for lateral flow. However, the calibration was only possible through the use of an inverse modelling procedure to select a matric potential which gave a ‘best-fit' to the appearance of saturated conditions in the dipwells. The calibrated model was subsequently able to accurately predict the fluctuations in the perched watertable to within one depth class in five soil profiles and only slightly greater than one depth class in the remainder. The technique offers the potential to extrapolate from a limited period of measured soil watertable data. However, care is needed as there were additional errors associated with the restrictions imposed by the model, by the input data and due to the nature of the calibration data.     

山西省天龙山弃耕地的根系呼吸及其影响因素

用去除根系法对山西省天龙山自然保护区弃耕地的根系呼吸进行了为期2a的研究。结果表明,弃耕地的根系呼吸速率具有明显的季节变化,与土壤温度的变化趋势相一致,夏季高冬春季低。2007和2008年3—12月的根系呼吸总量(以C计)分别为329.5和392.5g/m2。土壤温度是影响根系呼吸速率的主导因子,可以解释根系呼吸速率季节变化的79%~88%,土壤水分对根系呼吸的影响较小。包括土壤温度和土壤水分两个变量的双因素模型可以解释根系呼吸季节变化的81%~89%;根系呼吸占土壤总呼吸的比例具有明显的季节变化,为24%~54%;2007和2008年3—12月根系呼吸比例的平均值分别为24.9%和30.9%。     

四川盆地沙溪庙组地层(J2s)岩石发育土壤的系统分类研究

地理发生分类的紫色土在中国土壤系统分类中的归属一直受到高度关注,以四川盆地分布最为广泛的侏罗系沙溪庙组地层岩石发育的土壤为研究对象,在对19个典型剖面的成土条件、剖面形态特征和土壤理化性质分析的基础上,根据《中国土壤系统分类检索(第三版)》,确定了供试土壤的诊断层和诊断特性及其在中国土壤系统分类中的高级类别。结果表明,供试土壤归属于3个土纲、3个亚纲、7个土类和12个亚类;色卡确定的颜色上满足“紫色砂、页岩岩性特征”的剖面仅7个;但若在原颜色定义上增加“或色调为2.5YR~5YR,干态明度为4~6,干态彩度为3~4”条件,则有11个剖面的色卡定色符合“紫色砂、页岩岩性特征”,3个剖面的仪器定色符合该特征。     

不同养分和水分模式对水稻土化学和微生物学质量参数的影响

A field experiment was conducted from 1999 to 2002 to compare and evaluate the effects of nutrient and water regimes on paddy soil quality by investigating soil chemical and microbiological parameters. Four nutrient regimes, a control, chemical fertilizers only (CF), chemical fertilizers with swine manure (SM), and chemical fertilizers with wheat straw (WS), and two soil moisture regimes, continuous waterlogging (CWL) and alternate wetting and drying (AWD), were investigated. With SM and WS total organic carbon and total nitrogen in the paddy soil were significantly higher (P < 0.05) than those with CF. A similar effect for organic amendments was observed in the soil light fraction organic C (LFOC), water-soluble carbohydrates (WSC), and water-soluble organic C (WSOC). CWL, in particular when swine manure was incorporated into the paddy soil, markedly decreased soil redox potential (Eh) and increased total active reducing substances (ARS). Meanwhile, as compared to CF, SM and WS significantly (P < 0.05) increased soil microbial biomass C (MBC) and mineralizable carbon, with differences in AWD being higher than CWL. In addition, SM and WS treatments significantly (P < 0.05) improved rice above-ground biomass and grain yield, with AWD being greater than CWL. Thus, for ecologically sustainable agricultural management of paddy soils, long-term waterlogging should be avoided when organic manure was incorporated into paddy soil.     

Impact of profile water status on nitrogen use pattern of dry land barley under varying nitrogen levels

A field trial was carried out during 1993–94 and 1994–95 winter seasons on Udic Ustochrept to evaluate the performance of dryland barley under varying profile moisture status and nitrogen levels. Three levels of initial moisture status of the root zone profile were: wet (100% field capacity), moderately wet (50% field capacity) and dry (rainfed) as the main treatment. The sub treatments were 0, 40, 60 and 80 kg N ha^?1. During 15 to 60 days after sowing (DAS) availability of soil nitrogen and its uptake by the crop attained the highest values under wet regime. However, at 105 and 130 DAS dry moisture regime resulted in maximum values of both available soil nitrogen and plant nitrogen contents. In the same tune biomass production attained the higher values under wet regime as compared to the dry regime during 15 to 60 DAS and the trend was reverse at 105 DAS. Grain yield attained the highest value under dry regime followed by wet and moderately wet regimes. Irrespective of the profile moisture status both productivity and nitrogen use efficiency enhanced with the increase in nitrogen doses from 0 to 80 kg ha^?1. Role of nitrogen was more pronounced under wet regime.     

不同施肥制度对黄泥田土壤酶活性及养分的影响

对连续施肥23年的黄泥田土壤酶及土壤养分因子进行了分析,探讨长期不同施肥条件对土壤酶活性及土壤肥力的影响.结果表明,与对照相比,不同施肥制度(化肥、化肥+牛粪、化肥+秸秆回田)下土壤有机质增幅达19.5%～47.1%,氮素增幅达20.6%～47.9%,磷素增幅达36.7%～499.0%,钾素增幅达55.8%～80.0%.施肥提高了土壤脲酶、过氧化氢酶、转化酶和磷酸酶的活性,其中有机无机肥配施增幅达10.3%～28.6%.土壤有机质和养分含量与部分酶活性存在极显著或显著的相关性.表明黄泥田土壤酶活性与土壤肥力密切相关,可作为评价土壤肥力性状的生物学指标.     

Relationships among soil p test values for soils of differing pedogenesis

Abstract

Surface samples of 78 soils from the continental U.S. and Puerto Rico were obtained from the U.S. Soil Conservation Service National Soil Survey Laboratory. Phosphorus was extracted by the Bray PI (0.03N NH₄F in 0.025N HCl), Mehlich No. 1 (0.05N HCl in 0.025N H₂SO₄), and Olsen bicarbonate (0.5N NaHCO₃) tests. Soil chemical, physical, and taxonomic data were obtained from the National Soil Survey Laboratory. On the basis of soil taxonomy and weathering, soils were divided into calcareous, slightly weathered, and highly weathered groups. Linear regression analysis was used to compare obtained soil P test values. Coefficients of determination (r²) ranged from 0.30 to 0.89. The lower coefficients were obtained between Mehlich No.l and Olsen bicarbonate tests, as these extractants were developed for differing soil types. Using independent data sets, the regression equations provided accurate estimates of soil test P by one method from another.     

鄂中丘陵区土壤硒分布特征及资源量研究

目的土壤硒资源的利用和开发越来越受到人们重视,探明富硒土壤的分布状况,系统掌握土壤硒资源数量分布特征则是合理开发和利用土壤硒资源的前提条件。方法本研究以鄂中丘陵区湖北省钟祥市为研究区,以1∶5万土地质量地球化学调查评价工作为基础,用多目标区域地球化学调查规范中的双层网格化采样模式,采集分析2479件表层土壤样、60件深层土壤样、148件有效态元素土壤样,分析土壤硒含量分布特征及其与土壤类型关系,并用硒含量－土层深度直线关系式估算土壤硒资源量。结果研究区内深层土壤的硒含量普遍小于表层土壤硒含量;土壤硒赋存形态以惰性态为主,惰性态占73.05%,中等利用态占17.69%,交换态占8.31%,易利用态仅占1.40%;区内表层（0 ~ 0.2 m）和深层（1.2 ~ 1.8 m）土壤硒资源量分别为29.22 t和168.44 t;储硒量最大的两类土壤是潮土和水稻土。结论研究区土壤硒资源量较丰富,深层硒资源量大于表层;土壤中含硒物质主要来自于成土母质和生物化学活动的积累;土壤硒含量与有机质含量呈正相关,为此可通过加大秸秆还田力度、增施农家肥等措施提高土壤有机质含量,继而增加土壤硒资源数量。本研究结果可为湖北省土壤硒资源开发利用和富硒产业高质量发展提供理论依据。     

长期不同施肥条件下土壤微生物量及 土壤酶活性的季节变化特征

研究长期不同施肥条件下褐潮土微生物量碳（SMBC）、微生物量氮（SMBN）和土壤酶活性随季节的变化特征。结果表明,长期施肥条件下土壤SMBC、SMBN含量及土壤酶活性均表现出一定的季节变化。SMBC、SMBN含量在各施肥处理中的顺序为:化肥与猪厩肥配施处理（NPKM）化肥配施玉米秸秆处理（NPKS）单施化肥处理（NPK）不施肥处理（CK）,各处理之间差异显著(P0.05);施肥还显著提高了土壤脲酶、转化酶、碱性磷酸酶活性,有机无机配施的高于单施化肥的。除过氧化氢酶活性随季节变化显著下降外,SMBC、SMBN、酶活性的值一般在夏季（6月到8月）较高。通过双因素单变量方差分析表明,不同施肥制度与季节变化对SMBC、SMBN与酶活性的影响分别达极显著水平（P0.01）,不同施肥制度的SMBC、SMBN与酶活性的季节波动有极显著不同（P0.01）。     

不同土地利用方式下冻融期黑土水热过程观测研究

冻融是我国季节性冻土区重要的自然环境特征,冻融过程中土壤水热变化影响着生态系统的功能。本文利用长期定位试验,监测对比分析了东北典型黑土冻融过程中,传统耕作、草地和裸地3种土地利用方式下黑土水热动态变化规律。结果表明:观测期内,月尺度和日尺度上土壤温度、液态含水量和电导率变化趋势基本一致。不同冻融阶段,土壤温度表现为解冻期>始冻期>完全冻结期,土壤液态含水量表现为始冻期≈解冻期>完全冻结期,土壤电导率表现为始冻期>解冻期>完全冻结期。对于不同土地利用方式,土壤温度在各冻融阶段均表现为裸地>草地>传统耕作。在始冻期,土壤液态含水量和电导率均表现为裸地>传统耕作>草地。在完全冻结期,土壤液态含水量表现为传统耕作>裸地>草地,土壤电导率表现为裸地>传统耕作>草地。在解冻期,土壤液态含水量表现为草地>传统耕作>裸地,土壤电导率表现为传统耕作>草地>裸地。     

河南中西部典型褐土在系统分类中的归属

选取位于河南中西部褐土土类的7个典型单个土体作为研究对象,通过土壤剖面形态特征和理化性质的分析,确定了它们在中国土壤系统分类中的位置.按照《中国土壤系统分类(第三版)》诊断标准,供试剖面中诊断出包括黏化层、钙积层、雏形层、氧化还原特征、温性土壤温度状况、半干润土壤水分状况等诊断层和诊断特性,7个剖面中,4个划归淋溶土纲...     

商洛山区主要药用植物土地利用配置初步研究

根据区域土地资源合理利用及生态治理的要求,在调查分析商洛山区基本地貌类型、土地资源现状、特点及水土流失情况和水土保持状况的基础上,对商洛山区重点发展的12种中药材的生境特性、药用部位、土壤要求及其土地利用配置作了初步研究。