Drying half of the root-zone from mid fruit growth to maturity in ‘Hass’ avocado (Persea americana Mill.) trees for one season reduced fruit production in two years

We tested the effect of extended drying of half the root system on fruit yield and fruit Ca concentration, an indirect measure of fruit quality, in avocado (Persea americana Mill. cv Hass). In a field experiment on a sandy soil, withholding irrigation and plastic sheeting was used to dry the root-zone beneath the whole canopy (DD) or half the canopy (WD), compared with well-watered trees (WW). The irrigation water contained added nutrients and was slightly saline. Yield, shoot growth, leaf conductance, leaf and fruit water status and mineral concentrations of leaves and fruit were studied. The responses of treated trees were assessed in the following season during which normal irrigation practices were restored. With respect to yield, the WD treatment behaved the same as the DD treatment. It reduced yield by more than half and proportionately more than the reduction in water supply thus reducing irrigation efficiency. Re-watering did not restore yield of WD or DD-trees in the next season. The WD and DD treatments had no effect on the concentration of Ca in the fruit mesocarp and so are unlikely to affect fruit quality. The main impact of reduced water supply on the trees was fruit abscission and this was linked to dry soil around the roots rather than the water status of the leaves or fruits. We conclude that extended drying of half of the root-zone in one season reduced irrigation efficiency for two seasons by promoting the abscission of developing fruit to the same extent as occurred when the whole root system was exposed to extended drying.     

不同新能源类型密集烤房烘烤效果研究

通过烘烤试验对比,从烤房建造成本、运行参数、烘烤能耗用工、烤房控温精度、烤后烟叶外观质量、化学成分、经济效益等方面探索内置式生物质烤房、密闭式热泵烤房、光伏一体化烤房的烘烤效果,旨在为曲靖烟区筛选最适宜的烤房类型以及为烟草行业的绿色可持续发展提供理论依据。结果表明,密闭式热泵烤房烘烤能耗用工成本较低,控温精度、烤后烟叶质量、经济效益较好,是目前最适宜曲靖烟区的烤房类型；光伏一体化烤房建造成本高昂,且烘烤效果表现一般,目前推广难度较大,但可作为未来烤房的发展方向；内置式生物质烤房入门门槛较低,可在生物质颗粒供方市场成熟和电力配套设施不齐全的烟区加以应用。     

喹草酮与莠去津复配防除杂草效果及对高粱的安全性

为明确对羟基丙酮酸双氧化酶抑制剂类新型除草剂喹草酮应用于高粱田的可行性，于2018-2019年在温室和田间测定喹草酮与莠去津复配的除草效果及对高粱的安全性。温室试验结果表明，喹草酮与莠去津复配对狗尾草Setaria viridis和苘麻Abutilon theophrasti均有很好的防除效果，两者按有效成分用量比1：4~1：7配比对狗尾草的GR₅₀在134.40~168.92 g （a.i.）/hm²之间，明显好于喹草酮和莠去津单独施用时的GR₅₀，分别为150.53g （a.i.）/hm²和589.30g （a.i.）/hm²；两者复配对狗尾草的共毒系数在234.80~311.03之间，远大于120.00，显示出明显的增效作用；对苘麻的共毒系数在140.16~168.38之间，也表现出增效作用；对马唐Digitaria sanguinalis也有较好的防除效果；喹草酮与莠去津按有效成分用量比1：5复配的制剂在最高用量3 600g （a.i.）/hm²处理下，3个高粱品种生长均正常，且对高粱和杂草之间的选择性指数远大于6.59，对高粱的安全性高。田间试验结果表明，喹草酮与莠去津复配应用于高粱田对高粱安全，且对田间杂草野稷Panicum ruderale、虎尾草Rabdosia eriocalys、稗Echinochloa crus-galli、反枝苋Amaranthus retroflexus和藜Chenopodium album等均有极好的防除效果，2018-2019年对高粱田杂草的总株防效分别为94.2%和92.8%，鲜重防效分别为95.6%和94.2%，明显高于药剂对照50%异甲·莠去津悬浮剂土壤处理和37%二氯·莠去津悬浮剂茎叶处理的防除效果。表明喹草酮与莠去津复配应用于高粱田防除杂草效果良好。     

基于世界遗产监测经验的全球重要农业文化遗产监测体系构建

为了保护具有全球重要性的传统农业系统,联合国粮农组织于2002年发起全球重要农业文化遗产(GIAHS)保护倡议。经过十几年的发展,中国目前拥有的GIAHS数量最多,但也面临着GIAHS科学保护与有效管理的艰巨任务。作为遗产管理的重要内容,监测对提升遗产管理水平具有重要作用。科学有效的遗产监测不仅可以实现遗产自身的保护及其价值的维护,而且可以实现遗产地的可持续发展。然而,我国的GIAHS监测工作刚刚起步,尚未建立一套科学完善的GIAHS监测体系,也缺乏相关理论研究作为支撑。为此,本文在充分借鉴世界遗产监测经验与实践的基础上,对GIAHS监测概念与内涵、监测范围与内容、数据收集与管理等关键问题进行了详细阐述,并提出由三级监测网络、动态监测系统和两级巡视制度构成的GIAHS监测体系。动态监测系统是GIAHS监测体系的核心组成,包括监测范围、监测内容、监测方法、数据管理的多个方面。三级监测网络和两级巡视制度是GIAHS监测体系的基础保障,不仅有助于形成主动监测与监督巡视相结合的监测巡视机制,而且将监测数据汇交与评估意见反馈形成闭合回路,从而提高GIAHS保护与管理工作的科学性与系统性。研究结果不仅有助于丰富GIAHS监测理论,进一步推动中国的GIAHS监测工作,也能为国际GIAHS监测提供中国经验。     

洪水管理研究进展

介绍了洪水管理理念在国际上的萌芽和发展过程,详细分析了洪水管理在我国的发展历程,指出国内外洪水管理研究的不同之处,并对洪水管理研究在我国的未来发展进行了展望。     

森林公园景观开发价值评价

论述了森林公园景观开发中存在的问题及森林公园人工景观林存在的安全隐患；阐明了对策及建议，倡导提高森林公园人工景观林的可进入性和亲和力。     

农业灌溉节水潜力及回归水利用研究进展

目前,对农业灌溉节水潜力尚未形成一个统一、公认的概念,相应的评价和计算体系也没有很好地建立起来.对农业灌溉节水潜力方面的研究成果进行了全面的回顾总结,提出了存在的问题和以后研究的重点.指出不同尺度回归水重复利用的量化是合理计算真实节水潜力的关键.最后,对回归水重复利用研究计算方法进行了归纳总结,提出了考虑回归水重复利用率的灌溉节水潜力评价思路.     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

建筑造型给人的视觉印象

从建筑造型的体型美和立体美、静态美和动态美到外饰美和朴素美几方面论述了建筑造型在环境创造中给人带来的视觉印象的影响是很大的,为当代建筑设计创作提供参考。     

基于Web的陕北白绒山羊辅助育种管理系统的设计与实现

针对陕北白绒山羊多性状选择育种研究处于起步阶段的现状,以动物模型BLUP法为核心的多性状复合育种技术体系为依托,在Windows XP平台下利用ASP技术和SQL Server 2000数据库开发了一套基于Web的陕北白绒山羊辅助育种管理系统-ABMS。该系统能实时地管理分布在不同地域种羊场的生产性能测定信息,并能方便地导入和导出选择性状的育种数据。ABMS在陕北白绒山羊种羊场实际应用中体现了技术先进、易于操作、网络化管理等特点,其推广和应用对实现种羊场育种工作和生产管理的自动化,具有极大的促进作用。