农田残膜机械回收膜土分离模型的建立与仿真试验

为明确农田残膜机械回收过程中膜土分离机理，基于土壤接触理论及土壤黏附力学，建立残膜与土壤颗粒的接触模型和残膜与土壤颗粒间黏结合力变化的数学模型。利用EDEM软件，进行0.01、0.02、0.03 mm厚度残膜与黏附土壤剥离剪切仿真试验。拟合结果表明，0.01、0.02、0.03 mm残膜厚度下，膜土分离剪切力与剥离剪切位移均呈三次方关系，决定系数分别为0.805 9、0.872 2、0.878 4；对台架验证试验结果进行拟合，决定系数分别0.793 2、0.854 8、0.869 0，相对误差最大值为13.77%。     

生物多样性与地形及土壤因素对坡面产流产沙的耦合影响

生物多样性关系到生态系统的功能,而坡度和土壤因素是影响坡面产流产沙的重要因子。本研究基于黄土丘陵区生物多样性,并引入坡度、降雨前土壤含水量和土壤容重,探究其与坡面产流产沙总量的耦合关系。通过野外人工降雨试验,记录草本、灌木和乔木群落下的产流时间和产流产沙总量,并开展土壤植被调查。结果表明,与草本和乔木群落相比,灌木群落在延长产流开始时间和降低产沙总量上表现更优;植被群落功能离散度指数(FDiv)对产沙总量影响最大,Simpson指数(D)对产流总量影响最大,坡度仍然是不可忽视的第二重要影响因素;产流总量与坡度、土壤容重、D和功能丰富度指数(FRic)的回归关系优于产流总量分别与其的回归关系;产沙总量与坡度和FDiv指数的回归关系优于产沙总量分别与其的回归关系。植被保护与坡度改善将是该区水土保持规划工作的重点。     

黑土长缓坡地形与横垄对土壤有机碳空间分异的交互作用

横坡垄作对坡耕地土壤有机碳（soil organic carbon,SOC）流失有一定的阻控作用,但黑土区特有长而缓的地形与横垄对坡耕地SOC空间分异会产生交互作用,而这种交互作用引发的SOC流失风险没引起足够的重视。该研究以典型黑土区黑龙江省黑河市北安分局红星农场为研究区域,2022年在横坡垄作与顺坡水线方向上共布设25个采样点,采用地理探测器模型、单因素方差分析（one-way ANOVA）和Pearson相关性分析,探讨土壤有机碳的空间分异及其交互作用。结果表明,横坡垄作方向上垄沟土壤有机碳含量从坡顶到水线呈现逐渐增大的变化趋势;在垄台从坡顶到水线呈现先增大后减小的变化趋势。顺坡水线方向,土壤有机碳含量在垄沟呈现从上坡到下坡增大的变化趋势;在垄台呈现先增大后减小的变化趋势。由于断垄产生水线,顺坡土壤有机碳含量上坡与下坡仍有显著差异（P＜0.05）。Pearson相关性分析表明, 有机碳与可蚀性K因子呈显著负相关（垄沟和垄台相关系数分别为–0.228和–0.238,P＜0.05）,与碳循环相关的β-葡萄糖苷酶和微生物生物量碳在垄沟呈极显著正相关（相关系数为0.398和0.676,P<0.01）。地理探测器分析表明,顺坡水线对土壤有机碳空间分异的影响最大,其对垄沟和垄台SOC的解释力分别达到61%和52%以上;顺坡水线与其他因子的交互作用共同增强了对土壤有机碳的解释力,尤其是顺坡水线与高程的交互作用最为明显。黑土区坡耕地土壤有机碳空间分异主要受顺坡水线与高程的交互作用,横坡垄作虽然能够拦截径流,但由于长缓坡地形影响产生的断垄会加剧土壤侵蚀诱发的有机碳流失。因此,黑土坡耕地治理需要同时考虑横垄与地形的共同影响,从而实现防蚀的优化效果。     

Effects of Different Substrates on Fermentation Parameters

Fermenting different raw materials (corn, soybean meal and cottonseed meal) with three kinds of strains (Lactobacillus, yeast and Bacillus subtilis) were employed to optimize the fermentation parameter with sensory evaluation, pH and amount of probiotics retention.The results showed that the time to reach stable pH of materials with different substrates was different.Cottonseed meal had the longest time to reach stable pH followed by soybean meal, while corn had the shortest time under the condition of same water content.Different substrates had no effect on initial pH of corn, soybean meal and cottonseed meal.The count of the probiotics was also influenced by different substrates.When pH reached steady state, corn had the largest number of the probiotics followed by soybean meal and cottonseed meal.The color and smell of three materials after fermented had distinctive features.But cottonseed meal had the highest viscosity followed by soybean meal and corn.Because of shorter time and more microorganisms, corn was better than soybean meal and cottonseed meal to be fermenting medium.     

香根草防治公路边坡水土流失试验研究

香根草在公路边坡上试验种植后生长情况良好，其发达的根系能有效治理公路边坡的水土流失．是生物工程治理公路边坡的一种较好植物，有推广发展的价值。     

水土流失地区的相思栽培技术

通过在新会市罗坑一带的严重水土流失地段营造相思的试验结果表明，造林后１年其郁闭度一般可达０．８～０．９，有效地覆盖光秃的林地，达到了控制水土流失的目的。文中针对水土流失地区的特点，提出了一整套在严重水土流失地上营造相思林的技术措施。     

毛竹残次林分改造技术研究

本文对失管多年的毛竹残次林分采用封山育竹、劈草、锄草、深翻垦复和补栽毛竹等一系列营林措施，3年恢复毛竹成林，毛竹林面积从16．47hm2扩大到19．27hm2，立竹密度从555株／hm2提高到2295株／hm2,立竹平均胸径从7．2cm提高到9．9cm，3年后就能采伐利用，取得了显著的经济、生态效益。     

Towards a Pan‐European Assessment of Land Susceptibility to Wind Erosion

Understanding spatial and temporal patterns in land susceptibility to wind erosion is essential to design effective management strategies to control land degradation. The knowledge about the land surface susceptible to wind erosion in European contexts shows significant gaps. The lack of researches, particularly at the landscape to regional scales, prevents national and European institutions from taking actions aimed at an effective mitigating of land degradation. This study provides a preliminary pan‐European assessment that delineates the spatial patterns of land susceptibility to wind erosion and lays the groundwork for future modelling activities. An Index of Land Susceptibility to Wind Erosion (ILSWE) was created by combining spatiotemporal variations of the most influential wind erosion factors (i.e. climatic erosivity, soil erodibility, vegetation cover and landscape roughness). The sensitivity of each input factor was ranked according to fuzzy logic techniques. State‐of‐the‐art findings within the literature on soil erodibility and land susceptibility were used to evaluate the outcomes of the proposed modelling activity. Results show that the approach is suitable for integrating wind erosion information and environmental factors. Within the 34 European countries under investigation, moderate and high levels of land susceptibility to wind erosion were predicted, ranging from 25·8 to 13·0 M ha, respectively (corresponding to 5·3 and 2·9% of total area). New insights into the geography of wind erosion susceptibility in Europe were obtained and provide a solid basis for further investigations into the spatial variability and susceptibility of land to wind erosion across Europe. © 2014 The Authors. Land Degradation and Development published by John Wiley & Sons, Ltd.