不同增稠剂对农药可分散油悬浮剂稳定性的影响

为明确不同增稠剂对以矿物油为分散介质的油悬浮体系稳定性的影响,以12.5%丙炔·吡嘧(丙炔噁草酮·吡嘧磺隆)可分散油悬浮剂为对象,通过流变学和多重光散射方法,研究了有机膨润土、有机高分子和气相二氧化硅3类增稠剂单独使用及有机膨润土和其他两类增稠剂分别搭配使用对可分散油悬浮剂物理稳定性的影响。结果表明:所有样品的流动特性指数(n)均小于1,为假塑性流体,具有触变性。除有机膨润土和高分子增稠剂Atlox Rheostrux100组合使用时体系更符合Casson方程外,其余样品均更符合Herschel-Bulkley方程。单独使用时,有机膨润土对保证体系稳定的效果相对较好;Atlox Rheostrux 100和Atlox Rheostrux200两种高分子增稠剂的效果差别较大,其中Atlox Rheostrux 100效果更好,这可能是由分子结构差异造成;两种气相二氧化硅类增稠剂由于不能有效形成氢键,效果较差。将有机膨润土和有机高分子增稠剂组合使用时,体系的稳定性有所提升,其中有机膨润土869和Atlox Rheostrux 100组合使用效果更好,体系具有较高的黏度,且具有良好的触变性,物理稳定性优异;有机膨润土869和疏水气相二氧化硅R974组合使用时则效果没有明显的提升。研究表明,流变学和多重光散射两种方法均能较好地表征可分散油悬浮剂的物理稳定性;新型高分子增稠剂和有机膨润土具有协同作用,将二者合理组合添加能大幅提升可分散油悬浮剂的稳定性。     

不同间作绿肥替代化肥模式对木薯性状和产量的影响

通过探讨秸秆还田与化肥减施下间作绿肥对木薯产量性状的影响,着力解决连作木薯土壤肥力提高与改良相关技术的协调增效。于2019-2020年,以木薯品种“南美1号”为供试材料,设置8个处理,调查每个小区的木薯茎径、叶绿素（SPAD）、块根直径、块根长、单株茎秆鲜重、单株块根鲜重、株高、单片叶重、单株块根数以及小区产量等农艺性状。结果表明,处理5（木薯秆还田+化肥减量12.5%+12.5%营养元素当量黑豆绿肥还田）的木薯产量最高,并得到拟合方程。绿肥秸秆还田以及间作绿肥从整体上改良了土壤肥力,并通过显著影响木薯块根、单片叶重以及单株块根数而影响最终产量。     

Biochar and Conservation Agriculture Nexus: Synergy and Research Gaps for Enhanced Sustainable Productivity in Degraded Soils—Review

Degrading soil quality and productivity are major global challenges exacerbated by climate change and management practices. The dwindling global economy calls for other cost-effective approaches to address these challenges. This study reviewed a number of literatures on degraded soils, conservation agriculture (CA), and biochar soil amendment. The aim is to establish a base for more appropriate policy decisions and support for research on CA and biochar soil amendment nexus, which will enable the design of profitable and sustainable farming systems. Studies have highlighted the positive effects of CA practice, yet the adoption is low and some shortfalls have been reported. Likewise in the application of biochar as soil amendment, positive soil transformations have been recorded and some lapses. It is therefore imperative to explore the possibility of merging the two practices to see if the effects are complimentary, additive, or opposing in which case the positive values could be lost.     

煤矿区土壤有机碳含量的高光谱预测模型

可见—近红外光谱已被证明是一种快速、及时、有效的土壤有机碳含量预测工具。利用Field Spec4对济宁鲍店矿区的104个土壤样品进行光谱测量,采用Savitzky-Golay卷积平滑(SG)、多元散射校正(MSC)及数学变换等多种方式组合对光谱预处理,并运用偏最小二乘回归分析建立土壤有机碳含量预测模型,进而探讨煤矿区土壤有机碳含量的高精度预测方法。结果表明:(1)不同的光谱预处理方法对建模结果影响差异较大,建模结果以SG加MSC预处理再结合光谱反射率的一阶微分变换最优,建模R~2=0.86,RMSE=2.0g/kg,验证R~2=0.78,RMSE=1.81g/kg,RPD=2.69。(2)倒数和倒数的对数与土壤有机碳含量的相关性曲线接近重合,与反射率曲线成反比,但是建模效果远低于反射率;光谱反射率的一阶微分能明显提高500~600nm波段相关性。(3)光谱反射率随土壤有机碳的含量减少而增大,当有机碳含量较低时,其波谱的近红外波段反射率响应能力也随之降低,反射率直接建模难度加大。     

苏打型草甸碱土团聚体特征对长期有机培肥措施的响应

松嫩平原西部苏打草甸碱土具有碱性强、结构性差的特点。本研究以长期定位试验为基础,开展长期施用有机肥措施下苏打型草甸碱土团聚体特征的研究。根据有机肥施用年限,设置4个处理,分别为:施用有机肥5a(S5)、9a(S9)、12a(S12),以不施用有机肥作为对照(CK),每个处理重复3次,重点研究土壤水稳性团聚体分布特征、平均重量直径、几何平均直径、分形维数。结果表明:苏打草甸碱土经过有机培肥处理,大团聚体数量增加,小团聚体数量减少,有机培肥9a处理大团聚体含量(35.20%)最高;各有机培肥处理水稳性团聚体平均重量直径(27.54~54.22 mm)、几何平均直径(0.13~0.17 mm)均优于对照(13.48mm、0.08mm),分形维数(2.86~2.88)均小于对照(2.95),有机培肥9a处理土壤结构稳定性(平均重量直径54.22 mm、几何平均直径0.17 mm、分形维数2.86)最好;经回归分析,水稳性大团聚体含量与平均重量直径、几何平均直径呈正相关,与分形维数呈负相关。综合结果来看,有机培肥处理均促进了表层土壤大团聚体的形成,并提高了其结构稳定性,而有机培肥9a处理效果最好。     

Influence of organic amendments on dissipation kinetics of two different pesticides in soil: a case study

A study was undertaken to investigate the remedial effect of some soil amendments (farmyard manure (FYM), press mud compost (PMC), cereal straw (CS) at 5 t ha^?1 and fresh cow dung slurry (FCD) @ 0.5 t ha^?1) on dissipation kinetics of imidacloprid and sulfosulfuron under laboratory conditions. Incorporation of CS or FCD was found to be most effective in degrading both the pesticides at faster rates. Dissipation of both the pesticides could be well accounted by two component (1 + 1) first order kinetics. The computed values of parameters revealed that use of organic amendments increased the dissipated fraction of imidacloprid and sulfosulfuron. Incorporation of CS or FCD in soil maintained relatively higher dissipation rate constants for both faster and slower dissipation processes of pesticides in comparison to control. Hence, eco-friendly practices of CS or FCD incorporation as soil amendment in soil can play a vital role in preventing soil and water pollution.     

Plant protection means used in organic farming throughout the European Union

Following the obligatory implementation of integrated pest management in the European Union (EU), the plant protection means suitable for application in organic agriculture attracted the attention of quite a wide group of potential users. In spite of the common rules of organic production, as well as the uniform principles of placing plant protection products on the market, the availability of products that can be legally used in organic crop protection differs significantly among the Member States. There is a uniform list of 10 basic substances that can be used in the protection of organic crops throughout the entire EU. Twelve Member States have official registers of plant protection products for use in organic agriculture, and the total number of qualified products per country varies from 11 in Lithuania to 576 in Italy. Some products that improve plant vigour or resistance and may be of use in protection of organic crops are placed on the market as biostimulants. They fall under the law that governs fertilisers and the systems of their registration vary widely among the Member States. In addition, there exist a number of products that have been legally introduced onto the markets of some Member States without registration as a consequence of a loophole in the law. The use of unregistered products in organic agriculture raises some doubts, but currently it seems that there is no legal basis on which to explicitly prohibit the practice. © 2017 Society of Chemical Industry     

吸附到白浆土中铝的解吸行为研究

为探讨发生铝污染的白浆土中金属铝的解吸特性,采用平衡振荡法,研究铝在白浆土中的解吸行为及不同因素的影响。结果表明:在720min后,白浆土中的铝解吸基本达到平衡;25℃下,土壤有机质含量为42.2g/kg,铝在白浆土中的解吸量仅为吸附量的1.5%;用Langmuir方程可很好地拟合白浆土中铝解吸等温曲线(r=0.985 9**),说明表面均匀单层解吸占主导;热力学参数ΔG0,ΔH0,ΔS0,表明铝的解吸是自发、吸热和熵增加的过程。土壤有机质由42.2g/kg降至27.8g/kg时,白浆土中铝的最大解吸量由25.87mg/kg升至66.11mg/kg,且导致解吸滞后现象的加剧。pH降至3时,铝的解吸量升至226.4mg/kg,是pH在5~7时的8倍以上。随着解吸液中NaCl和Na_2SO_4浓度的增加,铝的解吸量增加。总之,吸附到白浆土中的铝解吸能力较弱,但pH和有机质含量降低,无机盐含量升高,铝的解吸量大幅增加,污染风险急剧上升。     

伊犁绢蒿种子黏液提取工艺及对畜禽粪便污水的净化效果

伊犁绢蒿种子遇水能分泌黏液，黏液物质具有良好的保水性、成膜性、增稠性和分散性，可作为新的天然絮凝剂应用于污水处理中。该文就影响黏液提取率的3个因素提取时间、液料比、提取温度进行探讨，同时用所提取的种子黏液对牛、猪粪便污水进行处理。响应面法结果表明，绢蒿种子黏液在该试验条件下的最高提取率为16.76%，提取条件为：提取时间3 h、液料比60∶1、提取温度64 ℃；畜禽粪便废水处理试验表明，牛粪便废水处理在黏液投加量为50 mg/L时，絮凝率为28%和COD去除率为32.7%；pH值等于6时，絮凝率为46%，COD去除率为44.6%。明矾的联合使用对絮凝有显著的效果，絮凝率和COD去除率最大分别为72.3%和61.3%。猪粪便处理过程中，在黏液投加量为20 mg/L时，絮凝率为30.9%，COD去除率为32.7%，在pH值为7时，絮凝率为29.3%，COD去除率为50%，明矾的联合使用下，絮凝率和COD去除率最大分别为62.6%和68.3%，达到了预想的处理效果。研究可为伊犁绢蒿种质资源在畜禽粪便污水处理方面的开发应用提供参考。     

3D格子Boltzmann传质模型模拟生物膜降解有机污水

以膜生物法有机污水处理为研究背景,将3D格子Boltzmann传质模型与多孔介质四参数随机生成法耦合,获得生物膜多孔介质详细的孔隙分布,进而对反应器内生化降解反应过程进行模拟计算。研究分析了生物膜孔隙率及孔隙分布对流动传质及生化反应性能的影响,并与试验结果比较证明了模型的可行性。结果表明:各方向生长概率p1-14=0.005,随着生物膜孔隙率增大,反应器内底物降解效率先增大后减小,且在孔隙率ε=0.5时达到最大,50.97%;孔隙率ε=0.5时,改变各方向生长概率重构获得5种不同结构生物膜,其降解效率随之改变,生物膜为结构1(p_(3-4)=0.01,p_(1,2,5-14)=0.005)时,底物降解效率最高,52.54%。因此,3D格子Boltzmann传质模型可用于膜生物反应器内的流动传质及生化反应过程的模拟,研究结果将对反应器的优化具有一定的指导作用。