Soil Solarization: Effects on Soil Microbiological Parameters

Soil solarization, obtained by covering soil with plastic films, is a useful practice able to reduce soil pathogen populations. Light plastic films (LPFs) are nowadays widely used especially in open and greenhouse vegetable crop cultivations in Southern Italy, as they are able to raise soil temperature more than 20°C above air temperature. The solarization treatment with LPFs is characterized by a low cost and low environmental impact.

The wide use of these technique causes a concern about the side effect of solarization on soil microbial populations, which are affected the same as plant pathogens by soil heating. As scientific literature pays scant attention to the effect of soil heating on soil microbial parameters, this paper studied the effects of solarization on soil microbial biomass, soil respiration, and soil enzymatic activity in the presence of organic amendments and the soil fumigant dazomet.

Solarization appears to be an effective practice able to control nematodes, even though it may cause serious stress on the soil microbial biomass. In addition, it was demonstrated that the organic amendments exert a protective role keeping soil microbial biomass and enzymatic activities protected from the detrimental effect of heating.     

Germination of <Emphasis Type="Italic">Juniperus procera</Emphasis> seeds in response to stratification and smoke treatments,and detection of insect-damaged seeds with VIS + NIR spectroscopy

Seeds of Juniperus procera collected from five provenances across its geographic range in Ethiopia were subjected to cold-moist stratification at 5°C or 10°C for 6–12 weeks. The effect of aqueous smoke solution in overcoming the light requirement for germination, and the potential of visible (VIS) and near infrared reflectance (NIR) spectroscopy for sorting sound and insect-damaged seeds were also investigated. Highly significant differences in germination were detected among provenances (P < 0.0001) and stratification periods (P < 0.0001), but not between temperature regimes (P=0.111). Seeds from the south and southeast distribution ranges had higher percentage germination after 6 weeks of stratification than seeds collected from north, northwest and central ranges of distribution. The smoke treatment did not affect germination regardless of whether the seeds were exposed to light. Exposure to light increased germination capacity three fold. Sound and damaged seeds were distinguished with 90% accuracy using VIS + NIR spectroscopy. It can be concluded that dormancy in juniper seeds varies with provenances, and cold stratification for 6 weeks alleviates dormancy in some seed lots. Tentatively, smoke treatment seems ineffective in overcoming photo-dormancy in juniper seeds. VIS + NIR spectroscopy has demonstrated a great potential for sorting damaged seeds, thereby upgrading seed lot purity.     

辽宁西部地区光热水资源变化对农业生产的影响

利用辽西地区1960-2009年的气象资料,应用常规数理统计方法,重点分析了近50a来在全球变暖背景下辽宁西部地区光热水资源的变化趋势,以及对当地农业生产的影响。结果表明:近50a来,辽宁西部光照资源下降幅度较大,年日照时数趋势减少406h;年平均气温和年≥0℃积温呈现明显的升高趋势,年平均气温趋势升高1.7℃,年≥0℃活动积温增加307℃.d;降水呈现出减少趋势,年降水量趋势减少62mm,在年代际尺度上波动显著。对于光照资源丰富的辽西地区来说,日照时数减少还未表现出不利影响;而气温升高、降水减少使该地区气候呈现暖干化趋势,这将对辽西农业的发展产生巨大影响。本文通过对光温水资源变化趋势的研究,旨在提高气候变暖对农业生产影响的认识,增强应对气候变化的能力,为农业结构调整提供依据。     

蓝孔雀人工繁殖控光实验

从2002年11月开始进行控光实验，共进行了3年。每次实验将蓝孔雀分成控光组和对照组，每组18只次，采用40lax白炽灯进行控光。实验结果为：控光组蓝孔雀每年平均产卵数量为424枚，对照组每年平均产卵数量为289枚，平均增加产卵数为135枚，平均增产率为46．8％，控光组平均每年受精比率为67．1％，对照组平均每年受精比率为67．4％；控光组孔雀卵的年均孵化率为89．3％，对照组孔雀卵的年均孵化率为90．2％。实验结果表明：控光使蓝孔雀的繁殖期明显提前，产卵数量明显上升；控光对蓝孔雀的受精率和孵化率影响差异不显著。     

Effects of 2, 4-Dichlorophenoxy Acetic Acid and Light on Growth of Gerbera (Gerbera jamesonii cv.Daxueju) Callus

This study was conducted to determine effects of 2,4-dichlorophenoxy acetic acid (2,4-D) and light on growth of gerbera (Gerbera jamesonii cv.Daxueju) callus.Callus was induced from both petiole and leaf explants of gerbera on Murashige and Skoog medium supplemented with 3％ sucrose and various concentrations of 2,4-D and placed under light and dark.Callus induction percentage,callus size and callus fresh and dry weights were efficiently higher when using petiole as explant.MS medium supplemented with 1.5 mg/L 2,4-D showed the highest callus induction percentage of 96.70％.Callus induced under light had larger weight mass.It was indicated that 1.5 mg/L 2,4-D and light could promote growth of gerbera callus from petiole explant.     

气候条件对曲靖烟区烤烟生产影响综述

气候资源是烤烟生产中自然资源的重要组成部分,适宜的气候条件是烟叶优质适产及形成特色烟叶最重要的基础因素之一。直接影响烤烟产量和质量的主要气候因素有光照、温度和降水三个因子。本文针对影响曲靖地区烤烟产量和质量的光、温、水气象条件进行综述,以期在栽培管理上趋利避害,更好的达到"适产优质"的目的。     

核盘菌一些生理性状的观察

用８科１５种作物秸秆培养核盘菌所产生的菌核数量和消耗比差异很大，不同秸秆产生的菌核萌发情况也不尽相同。此外，菜瓜上产生的菌核在５～３０℃范围内均可萌发，萌发适宜温度为 ５～１５℃ ，以 １０℃ 最为适宜；菌核萌发产生子囊盘与光照强度关系密切，３００ ｌｘ时不产生子囊盘，５００ ｌｘ时菌核萌发后 １０ ｄ产生子囊盘率为 ５８． ８％，７６０ ｌｘ时菌核萌发后 ７ｄ产生子囊盘率为１００％。     

穿龙薯蓣光合蒸腾特性

采用LI－6400便携式光合作用测定系统，测定了穿龙薯蓣与光有关的各项生理生态指标，讨论了光对穿龙薯蓣生长发育的作用及影响。结果表明，穿龙薯蓣对不同光照条件的适应性较强。     

水稻二化螟性诱测报与防治技术研究

为了研究二化螟诱剂的诱蛾能力与测报效果,进行二化螟性诱剂与灯光诱捕的测报对比试验.结果表明:二化螟性诱剂具有较强的诱蛾能力,其诱娥量高于灯光诱捕的诱蛾量,且受环境影响较小,诱测结果能够反映出二化螟当年发生的实际情况;二化螟性诱剂防治示范试验表明,性诱剂对二化螟有较好防治效果,可作为绿色防控的有效手段之一.     

带状套作复光后不同大豆品种干物质积累模型与特征分析

为了研究套作下高产类型大豆复光后的干物质积累特征,本研究共采用14个高、中、低产量水平的大豆为材料,比较了不同大豆产量类型品种与玉米套作,复光后的干物质积累特征差异。结果表明:1)高产类型大豆复光后干物质积累量为32.99 g·plant?1,较中、低产类型分别高26.82%和91.51%(两年均值)。2)不同产量类型大豆复光后干物质积累速率均呈先增加后下降的趋势,复光后最大干物质积累速率和平均干物质积累速率呈高产类型中产类型低产类型,高产类型大豆最大干物重积累速率的时间大致在复光后41~42 d,中低产类型则在复光后33~37 d;高产类型大豆复光后干物质渐增期天数、积累速率和干物质积累量以及快增期和缓增期的积累速率和积累量均显著高于中、低产类型。3)产量与最大干物质积累速率、最大干物质积累速率时间、平均干物质积累速率、渐增期的持续时间及干物质增量、快增期平均积累速率及干物质增量、缓增期平均积累速率及干物质增量呈显著正相关。本研究表明,套作下高产类型大豆复光后较强的干物质积累优势主要表现在复光后渐增期,而复光后渐增期较强的干物质积累能力主要在于其较长的渐增期持续天数。