Soil Potassium Indices and Clay‐Sized Particles affecting Banana‐Wilt Expression Caused by Soil Fungus in Banana Plantation Development on Transported Volcanic Soils

Abstract

Relations among the expression of banana disease symptoms caused by the soil fungus Fusarium oxysporum f. sp. cubense, soil potassium (K)–sodium (Na) properties [soluble K‐Na ratios (SK/SS), potential buffering capacity for K (KBC), potassium adsorption ratio (KAR)], and clay‐sized particles were evaluated in Sorribas plots from the Canary Islands. Soils were sampled in areas of Sorribas where banana plants show positive or negative wilting symptoms characteristic of Panama disease. The Bartoli method was used for soil dispersion (Na resin). This method was able to show a clear separation between diseased and disease‐free areas by the amount of clay‐sized particles. Results also show that the greatest SK/SS ratios and clay‐sized particles in soils from diseased areas could explain the increase of water‐stable aggregate mass in these soils and the release of available iron (Fe) to soil solution in diseased areas, at least in Sorribas cultivated soils under the arid climate conditions of the Canary Islands.     

乡村园林景观规划存在的问题及设计要求

总结了传统乡土园林的主要特点及景观范畴,分析了存在的问题,并提出设计要求,以期为乡村园林景观规划提供参考。     

作物青枯病研究进展

茄科雷尔氏菌侵染引起的青枯病是世界性、毁灭性的作物细菌病害，该病害是典型的土传病害。茄科雷尔氏菌属薄壁菌门β- 变形菌纲雷尔氏菌属，为革兰氏阴性、好氧棒状杆菌，可侵染50 多科200 余种植物。该病原菌在无寄主植物存在时可在土壤、水体中存活5 年以上，一旦有合适的寄主植物，即可通过寄主植物的根部侵染维管束系统，引起寄主植物整株性、不可逆的萎蔫枯死。茄科雷尔氏菌是一个复合种，具有明显的生理分化与遗传多样性，已发现有5 个生理小种、5 个生化变种、4 个演化型和57 个序列变种。作物青枯病在广东省多种作物上发生十分严重，是广东省重要的植物细菌病害之一。目前，至少发现有35 种植物受到茄科雷尔氏菌的侵染与为害，其中桑、桉树、甘薯、沙姜、南瓜、空心菜、菊花、向日葵、广藿香、胜红蓟和人参果等作物青枯病被首次发现与报道，每年均造成巨大的经济损失。对国内外茄科雷尔氏菌及青枯病主要研究进展进行综述，并总结了本团队近20 年来在青枯病研究方面取得的主要成效。     

林火对长白山自然保护区风灾区土壤性质的影响

以2012年长白山国家级自然保护区西坡风灾区森林火灾为研究背景，采用常规土壤分析方法研究了不同火烧强度下土壤理化性质的变化情况．结果表明：火烧后土壤容重和土壤含水率随火烧强度的增强显著下降；0～6cm土壤pH，土壤有机质，土壤全C、全N、速效P、速效K质量分数经轻度和中度火烧后均呈显著增加趋势；在火烧强度因子的控制下，对各养分质量分数进行的偏相关分析显示，除土壤pH外，其他各养分间存在显著的相关性．     

盐碱地的园林绿化工程改造

与从事盐碱地元绿化工程改造的同行朋友进行沟通与交流,不断提升盐碱地园林绿化工程改造水平,助推我国园林绿化工程建设实现更好更快地发展。     

痣鳞鳃金龟的生物学特性与防治

痣鳞鳃金龟二年发生一代 ,此虫在砂质土壤的林地密度大 ,为害严重。造林时在每株根际施 5g 3 %呋喃丹颗粒剂 ,可有效地控制此虫的危害并兼治其它地下害虫和造林初期的食叶害虫。     

高羊茅品种试验研究

１９９６年本所试验园进行了高羊茅品种特性对比试验，经过对供试草种的密度，均匀性，色泽，抗性等进行测定分析。结果表明；供试的６个品种，只要养护水平能跟上，在合肥地区均能保持四季常青。     

库鄯输油管道自动化系统

介绍了库鄯输油管道的ＳＣＡＤＡ系统的配置以及该系统所彩和的ＯＡＳＹＳ５．２系统软件的结构，特点与应用，ＯＡＳＹＳ５．２５系统具有良好的界面，能很好地与其它软件兼容。应用该系统可实现全线的启停高度自动化，在自动化管理方面达到了世界管道的先进水平。     

玉米田杂草马唐的生长特性研究

在田间和室内条件下研究了马唐的生长特性。结果表明 ,马唐种子具有短期休眠 ,其出苗的适宜土壤深度为 0 .5～ 4 .0cm ;随着密度的增加和出苗时间的推迟 ,马唐的单株生长量逐渐下降。     

Using the VS‐Fast methodology for soil degradation assessment: a case study from Senegal

Soil degradation threatens sustainable food production and accelerates global warming. Poorer countries, whose agricultural sectors are highly dependent on their natural resource bases, are hit particularly hard by declining soil productivity. Calls for soil‐quality monitoring are therefore, justified and this could inform decision‐makers on the preparation of appropriate interventions. However, the provision of monitoring methodologies is not an easy task. Soil degradation affects several soil characteristics that at larger scales cannot be evaluated with models or remote‐sensing techniques. Therefore, this study focuses on investigating the use of field‐based soil assessment methodologies to differentiate degrees of soil degradation. Specifically, we test the Visual Soil Field Assessment Tool (VS‐Fast) for detecting and monitoring soil degradation using a cross‐section of 71 sites in Senegal, the soil quality of which were classed by local experts. We found low correlation between VS‐Fast classes and expert assessments. By using an ordered logit model to quantify class boundaries, we show that experts categorized areas as ‘degraded’ for a wider range and higher VS‐Fast scores than the corresponding VS‐Fast class. Yet, from general linear models and analysis of variance procedures we found that areas classed by experts as ‘degraded’ had statistically significant lower VS‐Fast scores compared to those that were judged as ‘normal’ and ‘good’, while differences of the VS‐Fast scores between the latter two were negligible. It is remarkable that the visual assessment, the cheaper component of the VS‐Fast score, performs better in differentiating degradation status than its measured counterpart. The results support the need to investigate the applicability of other VSA methodologies that only use field observations and tactile methods.