基于工作过程的南疆高职院校园艺技术专业农业应用化学教学改革探析

分析了从南疆职业院校园艺技术专业农业应用化学教学中存在的问题,以提高该课程教学要求及园艺技术人才专业人才培养规格为目标,提出了对接教学领域与职业技能、职业素养,改革教学内容、课程体系、优化教学的方法和手段,为提高园艺技术专业服务育人本质,培养更多更好服务地方经济社会发展的高素质、高技能的园艺技术专业人才奠定重要的基础。     

Soil quality assessments in integrated crop–livestock–forest systems: A review

Integrated crop–livestock–forest is a promising strategy to improve soil quality. It comprises four different integrated farming systems: crop–livestock, crop–forest, forest–livestock and crop–livestock–forest. This work systematically reviewed studies about integrated crop–livestock–forest systems and soil quality. A total of 92 papers were retrieved from the Web of Science—Clarivate Analytics platform, and the following information was analysed: publication year, institution, region of the studied site, type of integrated system, soil type, tillage system, maximum soil depth and the soil quality indicators assessed. Most studies were published in the second half of the 2010s. Brazil is a prominent focus of research about soil quality and integrated crop–livestock–forest systems, with significant contribution from its central and southern regions. The Embrapa was the main publishing institution, present in over one‐third of the studies. Crop–livestock was the most common integrated system, Ferralsols was the most common soil group, and most of the studied soils were clayey. No tillage was the main tillage system. Most studies focused on the topsoil, assessing physical and/or chemical soil quality indicators. More emphasis on biological indicators of soil quality is required, as well as assessments integrating biological, physical and chemical indicators of soil quality. Future works should compare different integrated systems, including assessments deeper in the soil profile, especially in systems with the forest component, and also in sandy and silty soils. Soil quality indicators that have been rarely used should be further tested. Novel indicators should be added to better understand the promotion of soil quality by integrated crop–livestock–forest systems.     

A comparison of the effects of carbon dioxide and medical air for abdominal insufflation on respiratory parameters in xylazine-sedated sheep undergoing laparoscopic artificial insemination

AIMS: To determine if abdominal insufflation with medical air will improve oxygenation and ventilation parameters when compared to insufflation with CO₂ in xylazine-sedated sheep undergoing laparoscopic artificial insemination (AI).

METHODS: Forty-seven sheep underwent oestrus synchronisation and were fasted for 24 hours prior to laparoscopic AI. Each animal was randomised to receive either CO₂ or medical air for abdominal insufflation. An auricular arterial catheter was placed and utilised for serial blood sampling. Respiratory rates (RR) and arterial blood samples were collected at baseline, after xylazine (0.1?mg/kg I/V) sedation, 2 minutes after Trendelenburg positioning, 5 minutes after abdominal insufflation, and 10 minutes after being returned to a standing position. Blood samples were collected in heparinised syringes, stored on ice, and analysed for arterial pH, partial pressure of arterial O₂ (PaO₂), and CO₂ (PaCO₂). The number of ewes conceiving to AI was also determined.

RESULTS: Repeated measures ANOVA demonstrated temporal effects on RR, PaO₂, PaCO₂ and arterial pH during the laparoscopic AI procedure (p<0.001), but no difference between insufflation groups (p>0.01). No sheep experienced hypercapnia (PaCO₂>50?mmHg) or acidaemia (pH<7.35). Hypoxaemia (PaO₂<70?mmHg) was diagnosed during the procedure in 14/22 (64%) ewes in the CO₂ group compared with 8/23 (35%) ewes in the medical air group (p=0.053). Overall, 15/20 (75%) ewes in the CO₂ group conceived to AI compared with 16/22 (72.7%) in the medical air group (p=0.867).

CONCLUSIONS AND CLINICAL RELEVANCE: There were no statistical or clinical differences in RR, PaO₂, PaCO₂, pH, or conception to AI when comparing the effects of CO₂ and medical air as abdominal insufflation gases. None of the sheep experienced hypercapnia or acidaemic, yet 42% (19/45) of sheep developed clinical hypoxaemia, with a higher percentage of ewes in the CO₂ group developing hypoxaemia than in the medical air group. Based on the overall analysis, medical air could be utilised as a comparable alternative for abdominal insufflation during laparoscopic AI procedures.     

Seasonal Losses of Surface Litter in Northern Great Plains Mixed-Grass Prairies

Surface litter protects rangeland soils against wind and water erosion and provides food and nesting materials for wildlife and insects. However, the ability of grassland systems to provide these services depends on the little studied topic of seasonal surface litter decomposition. Seasonal and annual surface litter decomposition rates were determined between 2014 and 2015 in central and western South Dakota at three mixed-grass prairie locations. Residue bags containing surface litter were placed in the field in late fall (1 November) of 2014 and removed after the winter (1 April), spring (1 July), and summer + fall seasons (1 November) of 2015. The litter was analyzed for total C, total N, acid detergent fiber (ADF), and acid detergent lignin (ADL). Average winter temperatures ranged from −5^oC to −15^oC, while summer temperatures ranged from 10^oC to 35^oC. Litter decomposition was lowest during the winter (0.57−0.86 g [kg × day]⁻¹) and greatest during the summer + fall (2.12−2.69 g [kg × day]⁻¹). Over the entire season, 40.8−62% of the surface litter decomposed. Winter litter decomposition was positively correlated with air temperature (r = 0.62, P < 0.01) and snow depth (r = 0.61, P < 0.01), and negatively correlated with C/N ratio (r = −0.65, P < 0.01), ADF (r = −0.35, P < 0.05), and ADL (r = −0.25, P < 0.05) concentrations. These findings indicate that winter decomposition cannot be ignored and that winter surface litter decomposition increases with snow depth.     

兵团农机产业化的若干思考

农机产业化是社会分工细化、生产专业化深化的必然产物，其实质是传统农业转变为现代产业的过程。日前，兵团农机产业化进程中存在着一些问题。为此，结合兵团实际，提出了推进农机产业化发展的基本思路。     

金华市农业机械化投入机制初探

农业机械化是农业现代化的基础，是现代化的先决条件，发展农业机械化迫切需要加大投入。为此，分析了金华市现阶段农机化投入的现状及存在的问题；提出了通过建立政府、集体、信贷、农户、外资等“多位一体”的投入机制，加大农机化投入，促进农机化事业健康发展的思路。     

农机服务合作社运作模式初探

通过后塍农机服务合作社的运作实践和成功经验，总结了农机服务合作社运作的自身特点，提出其发展模式的几点探索意见。     

城镇化水平计算方法比较分析

城镇化是社会经济发展的必然趋势，与小城镇人口、经济实力、社会发展和环境保护等方面密切相关。城镇化判别指标归纳起来分两大类：一类是单一指标法或称主要指标法；另一类是多项指标法、复合指标法或称综合指标法。在常用的、单一指标法的城镇化水平计算方法中，城镇人口比重指标法和带眷系数法两种方法能够比较准确地反映小城镇的城镇化水平，尤其以城镇人口比重指标法计算结果最符合实际。     

活性炭吸附痕量银的研究

在静态、动态吸附条件下，分别选用果壳类净水用活性炭和煤质净水用活性炭对胶片工业废水中的痕量银的吸附行为进行了研究．结果表明，废水中的银浓度可降至＜５０ｐｐｂ，活性炭对银的吸附量达到３～５ｍｇ／ｇ．微孔发达的活性炭更适于吸附废水中的痕量银．随着银液浓度的升高，银液量增大，活性炭吸附能力增加．银液的最佳吸附ｐＨ值是５．