安徽省石灰岩风化物发育土壤的特性和系统分类

本文研究了安徽省石灰岩风化物的发育的土壤,根据土壤特性,依照《中国土壤系统分类（修订方案）》探讨８个土壤剖面在土壤系统分类中的归属,其中２个剖面为黑色岩性均腐土土类,１个剖面为钙质润湿淋溶土土类,５个剖面为钙质湿润雏形土土类。     

河南开封土壤养分变化特征及其持续利用途径研究

通过 1 984～ 1 998年河南开封不同土壤耕层有机质与氮磷钾养分分析 ,论述了不同农业利用方式和农田管理措施下不同土壤耕层养分的时空变化特征和硝态氮累积特性 .由于“重氮磷 ,轻有机肥 ,忽视钾素补给” ,土壤养分变化的总趋势以下降 ,钾素耗竭性明显 .土壤养分空间变化较为复杂 ,但不同土壤间耕层养分为普通淡色潮湿雏形土 >底锈干润雏形土 >石灰淡色潮湿雏形土 >灌淤旱耕人为土 >简育干润雏形土 >干润砂质新成土 .硝态氮累积表现为由上至下递减或由上至下递增和相对积累于土体某一深度 .最后研究提出了土壤持续利用的有效技术途径 .     

Piping and erodibility of loessic soils in Bergisches Land,Nordrhein‐Westfalen

In soils derived from loess on a range land site in the Rhenish Slate Mountains pipes were found at 120—190 cm depth above denser solifluction material. The pipes were 5—30 cm wide and 15—30 cm high. Various soil physical and chemical properties were determined and checked for their suitability as piping indicators. Silt contents reached 808 g kg^—1 in the piped soil sections where bulk densities were low to medium in comparison with clay rich and denser horizons beneath. Aggregate stabilities indicated by dispersion features, percolation rates, and dispersion ratios were suitable parameters to indicate piping vulnerability. Organic carbon contents tended to be low in the piped horizons, but there was no relationship between base saturation, ESP or EC values, and piping in the investigated soils.     

退化草地暗沃寒冻雏形土CO2释放的日变化和季节动态

采用CI-301PS红外CO     

20年来我国潮土区与黑土区土壤有机质变化的对比研究

对潮土区和黑土区的土壤样品进行采集和分析,结合第二次土壤普查资料,研究潮土区和黑土区土壤有机质的时空变化特征。结果表明潮土区土壤有机质含量呈现提高的趋势,黑土区土壤有机质含量呈现降低的趋势。出现这种变化的结果都与耕作制度,尤其是施肥管理水平等人为因素有密切的关系。     

The impact of erosion on the productivity of a Ferralsol and a Cambisol in Santa Catarina, southern Brazil

Abstract. The impact of soil erosion on soil productivity was estimated for a Rhodic Ferralsol and a Eutric Cambisol in Santa Catarina, southern Brazil. Over equivalent periods, total soil losses were an order of magnitude different (868 and 68 t/ha respectively on the bare soil control), yet the impact on maize yield per tonne of soil lost was far greater at the Cambisol site with less erosion. Similar interesting contrasts between sites were found for the other measures of impact with decline in pH and phosphorus and increase in free aluminium being the most obvious induced soil differences. The results demonstrate the variable nature of erosion impact according to soil type and they highlight the importance of examining a number of measures of impact before pronouncing on the sustainability of any particular agricultural practice.     

Organic C and N storage, and organic C fractions, in adjacent cultivated and forested soils of eastern Canada

As a major attribute of soil quality, organic matter is responsive to agricultural land use practices including tillage. A study was initiated in eastern Canada to characterize changes in the masses of organic C and total N, and organic matter fractions in forested and adjacent cultivated or forage sites. Generally, the cultivated and forage sites had denser soil profiles than the forest sites. Based on an equivalent soil mass, to accommodate differences in soil bulk density, the paired forest and cultivated sites showed that cultivation decreased the mass of organic C (35%) and total N (10%) in the soil profile of the Podzolic soils, but increased organic C (25%) and total N (37%) in the Brunisolic (Cambisol) and Gleysolic soils. For the Podzolic soils, use of forages increased soil stored organic C and N by 55% and 35%, respectively. Organic C fractions were mainly of significance in the A horizon. Soil microbial biomass C was greater in the forested, compared to the cultivated soil, but the proportion of soil organic C as microbial biomass C (1.3% to 1.6%) was similar. The proportion, however, was greater (2.1%) for the forage soil, compared to the corresponding cultivated (1.3%) soil, suggesting that organic C was continuing to increase under the former. The relatively large proportion (19%) of organic C found in the light fraction of forest soils in the A horizon was decreased (up to 70%) by cultivation. In contrast, the proportion of macro-organic C present in the soil sand fraction was not greatly influenced by cultivation. Overall, soils in eastern Canada have a relatively large potential to store organic matter. The study illustrates the importance of soil type and cultivation interactions for maintenance of soil organic matter storage, and the positive influence of forages in this regard in agroecosystems.     

草毡寒冻雏形土有机质补给、分解及大气CO2通量交换

调查草毡寒冻雏形土生物量及土壤有机质,利用涡度相关技术观测该区域作用层与大气CO₂通量。结果表明:地下90%生物量集中于0~10cm的表土层,年总净初级生产量约935.0g/m²;土壤有机质含量在6.401~7.060%之间;净CO₂通量呈明显的日变化和季节变 化规律;5月中 旬到9月底为CO₂的净吸收(780gCO₂/m²),其中以7月最高,净吸收量明显高于非生长季的,10月到翌年5月初CO₂的净排放量(383gCO₂/m²);全年固定碳高达397g/m²。     

青藏高原正常有机土与草毡寒冻雏形土地温观测的比较研究

在海拔高度相同、距离相近的纤维正常有机土与草毡寒冻雏形土地区，虽然区域气候一致，但二者地温具有显著的分布差异。从不同类型土壤４０～８０ｃｍ层次地温分布特征来看，草毡寒冻雏形土区域地温年平均３．０℃，变化剧烈，年较差大，０℃等值线可延伸至很深处。纤维正常有机土地温年平均１．４℃，变化较为平稳，０℃等值线只延至８０～９０ｃｍ左右。二类型地区地温随深度变化也有很大的不一致性。