中国日光温室结构优化研究现状及发展趋势

日光温室是中国设施农业的重要组成部分。日光温室的结构设计不仅影响内部环境因子和生产效益,而且对温室建造、生产成本及其结构稳定性和耐用性有直接影响。综述了地域和气候约束条件下日光温室主要结构优化设计的研究现状,如跨度、脊高、采光屋面角、采光屋面形状、墙体结构和后屋面结构等,为不同地区日光温室建造提供参考信息。同时,探讨了其计算机辅助结构分析研究状况,并分析了今后的发展趋势和待研究的问题。     

双屋面日光温室的结构设计和温光性能分析

为了提高日光温室保温蓄热能力和土地利用率,在普通日光温室基础上进行结构优化,建成了双屋面日光温室,并对其温光性能及土地利用率进行比较。结果表明：阳屋面日光温室在冬季最冷的1月份保温性能和蓄热性能明显优于普通日光温室,为喜温果菜的越冬安全生产提供了设施保障。双屋面日光温室的土地利用率提高到85%以上。阳屋面日光温室主要用于蔬菜越冬和春提前生产,阴屋面日光温室适于早春叶菜类和茄果类越夏连秋生产。     

教你设计日光温室

日光温室建筑设计中包括场地的选择、场地的布局以及温室各部位的尺寸、选材等。日光温室各部位的尺寸即是日光温室建筑设计参数,主要包括温室方位、温室跨度、高度、前后屋面角度、墙体和后屋面厚度、后屋面水平投影、防寒沟尺寸和温室长度等。在确定日光温室建筑参数时应     

内蒙古日光温室大风灾害风险区划研究

大风灾害是影响内蒙古设施农业生产的主要气象灾害之一,为给内蒙古设施农业规划布局提供科学依据,结合实地设施农业大风灾害调查数据,以地面大风观测资料和温室风载荷指标为基础,计算日光温室大风致灾指标,进行大风灾害预警等级划分,并通过构建设施农业风灾评估模型,研究内蒙古不同地区日光温室的抗风能力。从日光温室大风灾害综合风险指数来看,中、高风险地区主要集中在中西部地区,沿山地区风灾风险总体较高,尤其是阴山北麓地区,春、秋季灾害风险较高。原因是该地区主要成产季大风天气较多,危险性指数较高,同时阴山北麓地区海拔较高、人口密度较大,敏感性和暴露度较高,成为影响设施农业生产的主要风灾因子,因此,阴山北麓区在发展日光温室时要尽量避免大风天气的影响,东南部燕山丘陵地区风灾风险较低,考虑风灾的影响,该地区最适宜日光温室发展。本研究可为内蒙古设施农业风灾风险预警服务及风灾防御措施的制定提供技术支撑。     

新疆节能日光温室结构优化与应用研究 春小麦新品种博春1号及其栽培技术推广 新疆棉花高产栽培理论与技术研究

完成单位:石河子大学农学院 地 址:新疆石河子市 邮 编:832003 该课题主要完成了以下关键技术: (1)首次提出了新疆节能日光温室发展中的区划. (2)确定了高纬度寒冷地区节能日光温室结构参数. (3)在节能日光温室结构参数的确定中在国内又提出了一种新的、科学的、更合理的保温比概念,其具体概念是:温室内所有的受光面(包括地面、后墙、后屋面)及太阳辐射在其上的分布状况与散热面的比.其表达式为:保温比＝(温室内的土地面积×日照百分率×折减系数+内后墙面积×日照分布百分率+内后屋面面积×日照分布百分率)/透明屋面面积.保温比越大,温室的保温性能越好.     

日光温室蓝莓栽培技术要点

正蓝莓作为保健果品,市场需求量逐年增加,为满足市场需求,蓝莓保护地栽培应运而生。日光温室蓝莓栽培可提早上市两个月以上,不仅能延长蓝莓鲜果供应期,还能获得较高产量和更高的经济效益。笔者通过对多年保护地蓝莓栽培实践经验进行总结,形成日光温室蓝莓栽培技术要点,以供同行在生产过程中参考。一、温室建造1.温室类型蓝莓日光温室栽培,一般采用无立柱半拱形日光温室。前屋面为拱圆形,脊高3.5~4.2米,南北跨度10~11米,     

辽宁省日光温室雪荷载分布

为了计算出近年辽宁省日光温室这种特殊几何屋面建筑所受的基本雪压及雪荷载分布情况,利用辽宁省30年冬季降水数据,使用矩法、耿贝尔参数估计方法对极值I型分布函数的参数进行估计,比较参数优良性指标,进而计算30年一遇最大降雪量及基本雪压,结合辽宁省日光温室结构特点,确定日光温室积雪分布系数,最终得出辽宁省各地区日光温室雪荷载分布。结果表明：辽宁省30年重复期实际基本雪压与建筑规范中基本雪压标准值差距较大;辽宁省日光温室雪荷载范围为0.28~0.79 kN/m2。其中,以鞍山、岫岩、本溪、沈阳等中部地区雪荷载最大,由此向东西南北4个方向雪荷载逐渐减小。     

辽西优型标准化日光温室规划与建造技术

正日光温室是北方地区实现蔬菜越冬生产的基本设施,设计和建造一个优型的日光温室,是保护地内作物生产能够获得高产、优质、高效的基础和前提。因此,根据辽西地区实际,详细总结了辽西优型标准化日光温室的规划与建设技术,以供参考。优型日光温室规划与建造标准一是具有良好的采光屋面,能最大限度地透过自然光照;二是具有优良的保温和蓄热构造,能够在温室密闭的条件下,最大限度地减少温室散热;三是温室的长、宽、矢高和后墙高、前坡屋面和后坡屋面等规格尺寸及温室规     

山东ⅠⅡ Ⅲ Ⅳ Ⅴ型日光温室（冬暖大棚）建造技术规范

本标准规定了山东Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ型日光温室(冬暖大棚)建造的结构参数依据、结构参数、选址与场地规划，日光温室墙体、后屋面、骨架、覆盖物及建造、安装的操作技术。     

关于日光温室建造与无公害蔬菜生产技术标准化研究 ——国家“十五”科技攻关“东部沿海地区无公害蔬菜生产关键技术研究与示范”课题组

一、前言 辽南创建的日光温室及黄瓜栽培技术引入山东后，由于研究工作滞后，日光温室结构不合理的问题逐渐显现出来。在实施“山东新型日光温室蔬菜系统技术工程研究与开发”项目的过程中（1995-2000），项目组虽研究设计了山东Ⅰ、Ⅱ、Ⅲ、Ⅳ型日光温室及其结构参数。     

Assessment of runner bean (Phaseolus coccineus L.) germplasm for tolerance to low temperature during early seedling growth

The runner bean requires moderately high temperatures for optimum germination and growth. Low temperature at sowing delays both germination and plant emergence, and can reduce establishment of beans planted early in the growing season. The objective of this work was to identify potential runner bean germplasm with tolerance to low temperature and to assess the role of this germplasm for production and breeding. Seeds of 33 runner bean accessions were germinated in a climate-controlled chamber at optimal (17°C-day/15°C-night) and at sub-optimal (14°C-day/8°C-night) temperature. The low temperature tolerance was evaluated on the basis of germination, earliness, ability to grow and vigor. Differences in agronomical characters were significant at low temperatures for germination, earliness, ability to grow and early vigor except for emergence score. The commercial cultivars Painted Lady Bi-color, Scarlet Emperor, the Rwanda cultivar NI-15c, and the Spanish cultivars PHA-0013, PHA-0133, PHA-0311, PHA-0664, and PHA-1025 had the best performance under cold conditions.     

Greenhouse climate control affects postharvest tomato quality

In this study, important quality properties such as firmness, sugar and acid levels were measured and analysed in tomatoes harvested from three greenhouses during a five month period and stored at 16 °C for over 20 days. Tomatoes were harvested from three identical, neighbouring, greenhouses which were either conventionally ventilated (open greenhouse) or mechanically cooled (semi-closed greenhouses). Sugar and acids levels were hardly affected by greenhouse type. Compared to the open greenhouse, semi-closed greenhouses produced heavier and less mature (firmer) fruit at the commercial harvesting stage based on colour. Fruit maturity differences could be linked to the vertical temperature gradient and to CO₂ levels in the different greenhouses. This indicates that CO₂ levels and temperature affect the synchronisation between colour and firmness maturity at harvest. The acceptance period, i.e., the time period both tomato colour and firmness are considered acceptable by consumers, will likely be positively affected when growers switch from conventionally ventilated to semi-closed production systems. Additional to greenhouse effects also effects of the harvest month were observed. The sugar to acid ratio was highest and glucose to fructose ratio was lowest in July, the month with the highest irradiance, irrespective of greenhouse type. The estimated value for the maximum firmness (F_max) varied from 17.9 N in August to 31.2 N in June. This monthly variation in F_max explains an important part of the variation found in the postharvest behaviour of tomatoes. Interestingly, the monthly variation in F_max showed the same trend as found for the monthly initial sugar levels. It might be hypothesised that the monthly variation in glucose and fructose levels causes variation in that part of firmness that is generated by cell turgor. The monthly variation in F_max, sugar and acid levels could not be linked to climate conditions and remains to be elucidated.     

Influence of Soil Temperature on Seedling Emergence and Early Growth of Peanut Cultivars in Field Conditions

Peanut or groundnut (Arachis hypogaea L.) sown in early spring often has poor seed germination and seedling development. The influence of soil temperature on seedling emergence and early growth of six peanut cultivars (Florida MDR98, Southern Runner, Georgia Green, SunOleic 97R, Florunner and C‐99R) was studied in natural field soil profiles in temperature‐gradient greenhouses. We evaluated the influence of a range of soil temperatures by sowing at eight dates between January 2001 and May 2002 in Gainesville, Florida. On each sowing date, two additional temperature treatments (ambient and ambient +4.5 °C air temperature) were evaluated by sowing on either end of each greenhouse and applying differential heating. In total, 16 different soil temperature treatments were evaluated. Each treatment was replicated four times in four different greenhouses. Mean soil temperature from sowing to final emergence in different treatments ranged from 15 to 32 °C. Sowing date, temperature treatment and cultivar had significant effect on seedling emergence and development (V₂ stage). For all cultivars, the lowest germination was observed at the earliest sowing date (coolest soil temperature). Among cultivars, Florida MDR98 was the most sensitive to reduced (cool) temperature with the lowest germination and smallest seedling size at 21 days after sowing, followed by Southern Runner. Georgia Green was the most cold‐tolerant with the highest germination, followed by SunOleic 97R. There were no significant differences among cultivars for base temperature, which averaged 11.7 and 9.8 °C for rate of emergence and rate of development to V₂ stage respectively. These results imply that cultivar choice and/or genetic improvement of peanut for cold tolerance during emergence and seedling development in regions where cooler soil temperatures persist and/or regions where early sowing is desirable.     

Heritability of frost-seeded red clover establishment

In the colder parts of the United States (north of 32° N latitude and east of 92° W longitude), in late winter after disappearance of snow cover, red clover (Trifolium pratense) is often broadcast seeded into forage legume-depleted grass pastures to increase pasture forage quality. This method of establishment is referred to as frost seeding. However, in an estimated 30–40% of frost seeded pastures in Wisconsin, USA the legumes fail to establish. In this study 40 red clover halfsib families from one breeding population and ten check populations were evaluated for spring frost-seeded establishment in three environments. Seedling establishment counts and plant heights were measured 3 months after frost-seeded planting. One of the three environments experienced a stand establishment failure. Narrow sense heritability estimates on a halfsib family basis for stand counts and heights were 0.07 and 0.63, respectively. Seedling counts were greatly affected by environment with micro-environmental effects contributing to low heritability. Additive by environment genetic variance was large, again leading to low seedling count heritabilities. These results, based on one population, suggest that it may be difficult to select for increased frost-seeded seedling establishment and that many test environments are needed to achieve genetic gains for this trait. In comparison, seedling height was very heritable with relatively small additive by environment genetic variances. The genetic correlation between seedling count and height using frost-seeded establishment was r _A = 0.42.     

海南岛野生香蕉居群分布与居群内植物组成

野生香蕉有生长势和抗寒能力等优良特性,是香蕉遗传改良的重要种质来源。如何更好地利用和保护野生香蕉的遗传多样性,是目前急需研究解决的问题。本文调查研究了海南省野生香蕉的居群分布与居群内植物组成。海南岛野生香蕉（Musa itinerans）主要分布在北纬18°45′~19°19′,东经109°22′~109°56′之间, 年均降水量1800mm等值线以内的中部山区及其东部的丘陵地带,根据地形地貌、气候特征、植被类型和空间距离等因素,划分为黎母岭、阜龙乡、南高岭、鹦哥岭、百花岭、阿佗岭、大本山和吊罗山等八个分布区域。根据野生香蕉生物学特性的调查,认为海南岛这种大面积分布的野生香蕉为阿宽蕉（Musa itinerans）,基因型为AB型。阜龙乡野生香蕉居群内主要植物28种,其中乔本植物4种、灌木植物5种、草本植物8种、藤本植物4种和蕨类植物7种,野生香蕉为明显的单优群落,但也存在植物间的共生性和生长的竞争性。人工压力和生态胁迫是造成野生香蕉遗传资源流失的主要因素,周围自然环境的恶化,也破坏了野生香蕉居群内各动植物的协同进化,建议从维护原生境来保护野生香蕉种质资源,并建立完善的保护体系和野外监测体系。     

保留玉米油中甾醇的脱色工艺方法的研究

通过对脱色时间、脱色温度、脱色白土用量3个因素进行正交试验,确定最大限度保留植物甾醇的玉米油的最佳脱色工艺为:脱色时间温度为95℃,脱色时间为25 min,白土用量为3%,此时甾醇含量为768×10~(-6),与碱炼油甾醇含量1 152×10~(-6)相比,甾醇损失率为33.3%,此时脱色油的色泽为Y25 R2.5。     

坡度对云南红壤径流中磷素浓度的影响研究

水体富营养化的发生与农田土壤中磷的淋失有密切的关系。采用模拟降雨试验研究了土壤坡度对地表径流和亚地表径流中磷素浓度的影响。结果表明：在0°—10°范围内,地表径流中总磷、水溶性磷和颗粒态磷浓度和亚地表径流中水溶性磷浓度都随土壤坡度的增加而增加。亚地表径流中总磷和颗粒态磷在坡度为15°时均有一定程度的下降,其下降机理将做下一步分析研究。     

Recurrent Selection in Pearl Millet for Improving Stand Establishment at High Temperature

Inadequate stand establishment can be a major constraint to high grain and fodder yields of pearl millet (Pennisetum glaucum [L.] R. Br.) in the semi-arid tropics. In this study, two laboratory screening procedures designed to improve components of stand establishment were evaluated. In the first procedure the ability of seedlings to emerge from the soil at 45 °C was tested and in the second procedure the ability of seeds to germinate at 45°C was measured. Two cycles of recurrent selection were conducted with each procedure in the Higrop and Senpop pearl millet gene pools. The resultant populations were evaluated to measure the efficacy of the screening procedures. Selection for increased emergence was effective in the Cc of Higrop. When emergence percentage was averaged across Higrop and Senpop, recurrent selection increased emergence percentage by 7.4 % per cycle. In future, the size of the emergence screening units and number of seeds screened per progeny tested should be increased. The germination selection procedure was ineffective.     

一次南支小槽引发的贵州南部暴雨天气过程的预报偏差分析

为了准确分析和精细化预报贵州暴雨的落区情况,基于NCEP 2.5°×2.5°的FNL资料和常规天气图以及数值预报等资料,对2015年6月13日发生在贵州南部及东南部的一次大范围较强暴雨过程的成因和预报偏差进行分析。结果表明:高空低涡冷槽、南支小槽、低空急流建立是此次暴雨过程的直接影响系统;假相当位温锋区的位置对强降水出现的时次和位置有一定的指示作用,并且暴雨区上空低层负涡度、高层正涡度形成抽吸结构,涡度移动的方向与天气系统的移动方向比较一致。副热带高压的缓慢加强西进是阻挡降水东移的关键,近地层西北偏北路径冷空气的补充为暴雨天气提供了触发条件,而垂直速度则为强对流天气预报中提供了很好的指示作用。EC模式对贵州暴雨预报时次和量级效果较好,但对降雨落区存在偏差。     

毛乌素沙地城镇绿化可利用的野生观赏植物资源

扼要介绍了毛乌素沙地的地理位置与气候特点,对沙区可用于城镇绿化的主要野生观赏植物进行了比较详细地论述,并提出了可行性利用与保护措施。毛乌素沙地位于北纬37°30'~39°30',东径107°20'~111°30',面积4.22万km2,海拔1000~1600 m,包括内蒙古伊克昭盟的南部、陕西榆林市北部和宁夏东北部,涉及14个县（旗）的150多个乡镇。经野外调查统计,毛乌素沙地野生观赏植物种类丰富,共有83科、170属、499种（含变种）。引种试验表明,一些野生观赏植物或形态各异,迎霜傲雪;或花色艳丽,五彩缤纷,令人赏心悦目,具有较高观赏价值。尤其是耐寒、耐旱、耐瘠薄,抗风沙,适宜在毛乌素沙区推广种植,绿化美化沙区城市环境,创造具有沙区地方特色的园林景观。