吉林西部草地次生盐碱化与改良治理

本文探讨了松嫩平原草地次生盐碱化的发生原因、形成过程和治理途径。认为人类过度利用造成植被退化是草地次生盐碱化的主要原因。羊草作为羊草草地植物群落优势种,其数量指际(重要值,Important Value, Ⅳ)作为草地植被退化指标,与土壤电导率(EC)和碱化度(ESP)的函数关系分别为:;Ⅳ=50.07·0.69~(EC)((?)=—0.8499和Ⅳ=64.02·0.97~(ESP)(r=—0.7501)。表明随着土壤盐碱化程度的提高,羊草在群落中的优势度(Ⅳ)呈鱼指数形式下降。并提出了“避重就轻、先易后难、以防为主、用改结合”的治理原则和“以生物改良方法为主的治理途径”。对建立草地畜牧业优化生态模式具有一定的参考价值。     

齐齐哈尔市草原盐碱化成因及综合防治措施探析

通过自然、人为、生物诸因素，探讨了齐齐哈尔市草原盐碱化的成因，并提出了综合防治措施。     

不同改良措施对晋北盐碱土盐碱障碍和青贮玉米氮素吸收的调控

2019-2020年,本研究以晋北大同盆地的中度盐碱地为研究对象,分析不施肥(CK)、常规施肥下添加生物质炭和CaSO4(L)、常规施肥下添加生物质炭和CaSO4及种植2,3,4行(LC1,LC2,LC3)绿肥等5个处理对土壤pH、土壤盐分含量、钠吸附比(Sodium adsorption ratio,SAR)以及作物...     

THE ECOLOGICAL DISASTERS IN NINGXIA AND THE COUNTERMEASURES

<正> Ningxia lies in the midland of China, along the upper and middle of the Yellow River.The south of the region belongs to the Loess Plateau and the north of it is Part of theMongolian plateau. The main feature of the climate in the whole region is dry or half dry.The ecological enviroment is in a very delicate state and human activities have made itworse. The severe consequences are widely-spread various types of ecological disasters. All     

LAND UTILIZATION COUNTERMEASURES AND CURRENT SITUATION OF HETAO IRRIGATION REGION IN INNER MONGOLIA

<正> Hetao irrigation region is situated in the western part of Inner Mongolia. It stands bythe Yin·Shan mountain in the north, leans against the Yellow River in the south, nears theeastern side of Ulanbuhe Desert in the west and borders on Baotou in the east. It is 280kilometers in length from east to west. and 45-90 kilometers in width from north to south.     

Digital soil mapping to enable classification of the salt-affected soils in desert agro-ecological zones

Digital soil mapping is critical when quantifying the relationship between soil types and their associated bio-physical environments. Digital mapping of regional soils affected by salt is essential when monitoring the dynamics of soil salts and planning land development and reclamatation schemes. In this paper, an easy method for digitally mapping salt-affected soils is proposed. This method allows the construction of the quantitative lower categories of soil classification based on Chinese Soil Taxonomy by using a geostatistical method and GIS technology. The data and maps used in this study were collected during a soil survey of salt-affected desert agro-ecological zones in Karamay, Xinjiang Autonomous Region, China. The survey covers an area of 525 km² and includes 205 soil profiles. In addition, a classification and indicator system for the salt-affected soil in the region was established and 30 salt-affected soil types were identified. Three key soil classification indicators, viz. soil texture, texture stratification combination and total soil salinity, were selected to enable low-category soil classification. Furthermore, the information regarding climate, vegetation and topographic and geomorphologic features of the region was integrated into the analysis. A GIS-based regional digital soil classification map was then generated for three layers (0-30 cm, 30-60 cm, and 60-100 cm) after the observed soil salt distribution map and soil texture stratification maps were overlaid. This map would be used to draw up the strategies of the salt-affected soils improvement in desert. While compared with the conventional approaches, this new digital soil mapping method has the advantages of being prompt, quantitative, more objective, simpler and easier to update.     

辉河保护区温性草甸草原植被群落结构和碳储量对盐碱化的响应

为阐明草地盐碱化过程中草地植物群落结构及碳储量的变化,以辉河保护区内的天然草地、草地-盐碱地过渡带和盐碱地为研究对象,采用野外调查采样结合室内分析的方法进行测试研究。结果表明随着草地盐碱化加剧,植被群落结构组成趋于简单化;植被碳储量和生态系统碳储量均逐渐下降,表层土壤有机碳储量表现为过渡带>盐碱地>天然草地。植被碳储量的变化主要与地上植被类型、植被生长特性和土壤理化性质有关;表层土壤有机碳储量的变化主要是地上植被和土壤水分与不同盐碱化草地相互响应的结果,其中,pH会显著影响表层土壤有机碳储量(P<0.05);生态系统碳储量的变化受到植被更迭和土壤pH的影响。因此,温性草甸草原植被群落结构和碳储量均会受到草地盐碱化的影响。     

基于光谱分类的土壤盐分含量预测

基于相似土壤组分和光谱特征,利用土壤光谱反射率数据和曲线特征来进行土壤光谱分类,同时充分挖掘有效信息是光谱分析的重要应用方向之一。借助模糊k-均值聚类方法将土壤光谱数据分成四个类别(分类前先将原始光谱进行范围归一化处理),比较分析了不同类型土壤在光谱分类前后的高光谱特征,然后利用Kennard-Stone法将各类别样本划分为建模集和预测集,将预处理后的建模集光谱数据作为输入量,采用偏最小二乘回归法(PLSR)方法建立全局和各自类别的盐分预测模型。结果表明:光谱分类建模较按土壤系统分类建模和全局建模的精度有明显提高,其预测模型总体的预测决定系数RP2、预测均方根误差RMSEP、相对分析误差RPD和RPIQ(样本观测值三四分位数Q3与一四分位数Q1之差与RMSEP的比值)四个指标分别从0.664、1.219、1.733和1.461提高至0.818、1.132、2.356和2.422,其中RPD提高幅度达23.13%,四个类别所建模型RPD均大于2.0,可以对土壤含盐量进行较为精确的定量研究。研究结果为利用大样本光谱数据建立大尺度区域的盐分等土壤属性预测模型提供一种新的思路和方法。     

有机物料改良盐碱土的效果研究

采用盆栽试验方法 ,研究了在盐碱土中分别施入不同比例草炭和风化煤的改良效果及对作物的增产效果。结果表明 :草炭和风化煤增加了土壤速效养分 ,降低了土壤的 pH值、ESP、Na+/K+、Na+/Ca2 +和Na+/Mg2 +,增强了土壤的团聚性 ,改善了盐碱土的养分供应状况 ,增加了作物的产量。各处理中以施入 4%草炭的增产效果较好。     

劣质水灌溉条件下砂壤土盐碱化研究

天津市水资源短缺,污水排放量大、回用率低,污灌年限长,土壤盐碱化复杂多样、程度高,采用室内模拟的方法,研究利用典型劣质水灌溉砂壤土后,土壤中盐分的迁移变化。结果得出,劣质水灌溉后土壤的pH值低于清灌,全盐量、SAR、ESP稍高于清灌。在小麦根系活动层,清水灌溉后,砂壤土由中度碱化土减轻为非盐碱土和轻度碱化土;劣质水灌溉后,土壤由中度碱化土减轻为轻度碱化土和中度碱化土。