坡面过程、块体移动和土壤侵蚀研究进展

Soil erosion and land degradation are global problems and pose major issues in many countries.Both soil erosion and mass movement are two forms of land degradation and humans play important roles in these geomorphological processes.This paper reviews slope processes associated with mass movement and soil erosion and contributory factors,including physical and human agents.Acting together,these cause diverse geomorphological features.Slope processes are illustrated by reference to case studies from Brazil and UK.The causes and impacts of erosion are discussed,along with appropriate remedial bioengineering methods and the potential of the measures to prevent these types of environmental degradation.Although there are several agents of erosion,water is the most important one.Cultivation can promote soil erosion,due to ploughing and harvesting,which moves soil down slopes.Soil erosion and mass movement data would inform the viability of soil conservation practices.Integrated management of drainage basins offers a promising way forward for effective soil conservation and soil remedial bioengineering in Brazil and UK.     

Integrated analysis of changes in soil microbiota and metabolites following long-term fertilization in a subtropical maize-wheat agroecosystem

Although the application of inorganic fertilizer is a widespread agronomic practice used to boost soil productivity and crop yields, the effects on soil microbiome and the metabolic mechanisms involved in the high-yield response of crops to long-term fertilization remain poorly described. In this study, combined metagenomic and metabolomic analyses were used to explore the mechanism of crop yield response to the 20-year application of nitrogen-phosphorus-potassium fertilizers in a subtropical ag...     

油菜根系固土拉力的原位测定研究

应用锚杆拉力计和自行没计的剪切箱对不同根系密度的油菜根系固土能力在10 cm深度进行了原位测定.结果表明,当施加载荷达到3.5 kN时,生长有油菜的土壤样方1(根系密度为1.11 kg/m3)位移为38.0mm,生长有油菜的土壤样方2(根系密度为0.57 kg/m3)位移为46.0 mm,而裸土样方位移为49.7 mm.土壤样方内根系密度越大,达到土壤样方与土体分离的特征点所需要施加的载荷就越大.土壤样方1的屈服拉力点为3.5 kN,抗拉极限点为4.0 kN;而土壤样方2的屈服拉力点为3.1 kN,抗拉极限点为3.5 kN.该测定方法可以在水土保持上作为评价不同作物(植物)固土能力的有效参考手段.     

香根草根系固土拉力的原位测定

 应用锚杆拉力计和项目组自行设计改进的剪切箱,原位测定了不同深度（10cm,20cm）分蘖期香根草根系固土、单根拉力。结果表明,在给香根草施加载荷初期,根系都会发生弹性形变,荷载与位移都按比例增加,呈现一定的线性关系。当载荷超过根系抗拉极限后,随着拉力的继续增加,根系发生塑性形变,载荷与位移关系逐渐偏离直线,反映出非线性弹性特征,测定的土体样方与土体分离。但与裸土样方相比,在施加同样载荷的情况下,有根样方位移明显要小于无根样方,说明香根草具有一定的固土能力,并且根系入土越深,植物固土能力越强。     

利用农民指标评估中国云南省坡地土壤耕作系统的可持续性研究

Diversity in the biophysical and socio-economic attributes of agricultural systems makes them uniquely niche based. Farmers are expert in local biophysical and socio-economic situations and can contribute in developing pragmatic indicators of agro-environmental development. During evaluation of an agricultural research project in Yunnan, China, local farmers were capable of evaluating the effects of modified technologies on existing cropping systems and discussed their attitudes to the interventions using their own indicators. Farmers’ response can be grouped into seven major aspects: i) effects on income, ii) effects on production resources, iii) effects on crop management, iv) existing local knowledge about the technology, v) availability of inputs, vi) access to information, and vii) socio-economic conditions of farming households. Farmers concluded that environmental conditions in the experimental catchment in comparison to an adjacent untreated catchment were better in terms of soil and water losses, vegetation cover and natural resources, infrastructures and catchment management, use of environmentally-friendly technologies, and crop productivity. Success in soil and water conservation programmes depends on the efforts of the farmers and other local users and their greater involvement helps to identify more pragmatic indicators. Furthermore, it increases ownership of the programme, enhances interactions with the project scientists, increases farmers’ awareness of agro-environmental problems and their possible consequences. These development will enable scientists to develop better targeted interventions and increase the likelihood of adoption of tested technologies by local communities. The use of paired adjacent catchments improved evaluation activities and is proposed as good practice for future catchment improvement programmes.     

玉米根系原位固土力学特性研究*

 通过采用自制的剪切箱和锚杆拉力计对玉米（云瑞8号,Zea mays.L）根系在10cm和20cm两个深度上和空地样方的固土能力进行了原位测定比较。结果表明,施加相同载荷时,两种深度空地样方位移大于有根玉米样方;20cm深度样方位移为4个样方中最小。作物扎根越深,达到剪切分离样方特征点所需的载荷越大。10cm玉米样方屈服拉力点载荷为2.7kN,抗拉极限点载荷为2.9kN;20cm玉米样方屈服拉力点载荷为3.6kN,抗拉极限点载荷为3.61kN;10cm空地样方两点载荷分别为2.3kN和2.5kN;20cm深度空地样方载荷分别为3.1kN和3.4kN。该方法可直接量化测定玉米根系固土能力,为农业水土保持提供了有效研究手段。     

油菜根系固土拉力的原位测定研究*

 应用锚杆拉力计和自行设计的剪切箱对不同根系密度的油菜根系固土能力在10cm深度进行了原位测定。结果表明,当施加载荷达到35kN时,生长有油菜的土壤样方1（根系密度为111kg/m3）位移为380mm,生长有油菜的土壤样方2（根系密度为057kg/m3）位移为460mm,而裸土样方位移为497mm。土壤样方内根系密度越大,达到土壤样方与土体分离的特征点所需要施加的载荷就越大。土壤样方1的屈服拉力点为35kN, 抗拉极限点为40kN;而土壤样方2的屈服拉力点为31kN,抗拉极限点为35kN。该测定方法可以在水土保持上作为评价不同作物（植物）固土能力的有效参考手段。