三峡库区容器快速育苗成型带果定植技术及其效益研究

三峡库区是我国柑橘种植优势区域。近年来因品种更新带来的柑橘生产成本增加成为三峡库区柑橘发展的突出问题。容器快速育苗成型带果定植技术通过集约化管理降低生产成本,通过缩短童期加快新品种更新并迅速投产,实现定植当年即可结果,第二年逐步丰产,为三峡库区柑橘产业健康可持续发展提供有益的实用技术借鉴。     

三峡库区柑橘无疫容器苗繁育技术

摘要：秭归县柑橘良种繁育中心以国家现代柑橘产业技术体系三峡库区脐橙综合试验站为技术支撑,主要从事柑橘良种引进、选育、试验示范和良种繁育等工作。年产柑橘容器育苗180万株,年对外销售容器苗100余万株。本文从育苗场地建设、营养土配制、播种移栽、无疫苗嫁接管理及病虫害防治等方面,论述了柑橘生产无疫苗木的技术要点,对各柑橘产区苗木生产、引种等具有很好的指导和借鉴意义。     

不同容器规格、基质配比对酸柚苗生长发育的影响

为了研究不同规格容器、基质配比对酸柚苗生长发育的影响,本试验通过4种不同材质规格的容器和2种基质配比处理,研究分析其对1年生酸柚苗生物量的影响。结果表明,随着容器规格的增大,酸柚苗苗高、地径和生物量等指标均出现显著提高的趋势,这说明大规格的容器对酸柚苗的生长发育具有促进作用,4种规格容器对苗木的生长发育影响依次为A4>A3>A2≥A1;2种不同配比基质中B2基质黄泥土含量相对较高,其生物量也相应高于B1,其互作对容器育苗的生长发育无显著性影响。综合考虑不同容器的使用效果和成本等因素,筛选出综合成本低,管理操作方便,对苗木生长良好的容器,本试验初步筛选容器A4×育苗基质配比B2组合的容器育苗方式。     

孟家岗林场发展容器育苗提高造林成活率

容器育苗,其特点是种苗质量好、节省种子、抗逆性强、不受季节性限制,繁殖快速,繁殖量大,成本低等.用容器袋苗木造林是带营养基栽植,所以能很好地保护苗木根系,防止根系受损伤,防止苗木缺水,能有效地保证和提高造林成活率.孟家岗林场通过近几年的工作实践,对用容器育苗技术进行了归纳,总结了该项技术的操作要领,以及在当前林业发展的新形势下,该项技术的诸多优点,值得大力推广和应用.     

嘉陵地区柑橘果园生产成本分析

通过调查嘉陵区不同柑橘果园的生产日志,分析了该区柑橘果园生产成本构成及其比例。在调查的三个柑橘园中,肥料成本占比最高,占总成本的31.40%~46.18%,其中肥料成本中59.30%~89.70%来自复合肥;施肥、除草、喷施杀虫杀菌剂在三个果园中用工成本占比较高;农药、果袋、水电等其他成本分别占总成本的11.21%~21.12%、8.72%~16.25%。为今后该地区果园成本管理提供依据。     

生活污泥堆肥在柑桔容器育苗上的运用

为培育出优良的柑桔幼苗,通过对生活污泥堆肥在柑桔容器育苗基质配方试验的分析,结果表明：柑桔容器育苗基质配比为谷壳：河沙：污泥堆肥=1:1:（2~3）时,柑桔幼苗长势明显优于对照组。污泥堆肥具备替换泥炭资源的潜力,并能够节省肥料,同时也为生活污泥处置困难的问题提供了思路。     

蚕种场桑园营养土方格育苗一步成园技术探讨

本文对种场桑园营养土方格育苗一步成园技术作了详细介绍,并与传统桑园轮换方法进行比较,其结果是营养土方格育苗一步成园,每667m^2可节约人工16．25％、成本12．92％,所栽苗木长势和抗逆性都明显优于传统桑园轮换方法所栽的苗木。     

基质和沙土不同配比对蒙古莸容器苗生长的影响

蒙古莸为马鞭草科莸属的一种旱生灌木,具有药用、观赏、提取芳香油等较高的经济价值,抗性强,可用于水土保持和园林绿化。容器育苗作为当前广泛应用的苗木生产技术,采用容器育苗对于加快蒙古莸繁育应用具有重要意义,本试验利用基质和沙土作为原料,研究基质和沙土不同配比对蒙古莸容器苗生长的影响,以期筛选出较为经济、适用的基质配比。结果表明,基质和沙土不同的配比对蒙古莸的苗高度、地径和生物量的生长产生一定的影响。随着沙土比例的增加,蒙古莸高度、地径和生物量随之降低。但处理1、处理2、处理3间的高度与生物量生长间不存在显著差异,处理1与处理3间地径间有显著地差异,由此可知处理2和处理3为较理想的沙土与基质配比比例。     

丛枝菌根真菌在不同基质下对枳砧容器苗生长

为促进AM真菌在柑桔砧木容器苗生产中的高效应用,本研究以枳砧为供试植物,选取腐叶土、麦糠和菌渣为主要栽培基质,以摩西球囊霉（Glomus mosseae）、地表球囊霉(Glomus versiforme)、地球囊霉(Glomus geosporum)和透光球囊霉（Glomus diaphanum）为供试菌种,采用容器育苗方法,研究了7种丛枝菌根真菌及其组合处理在三种基质下对枳砧木容器苗生长及其氮、磷吸收的影响,以筛选出适合枳砧木苗生长的菌根种类及基质组合。试验结果表明自然接种的侵染率不超过40%,而人工接种的侵染率可高达80%;混合接种的侵染率显著高于单一接种;枳砧木苗以地表球囊霉（GV）接种和腐叶土或麦糠组合侵染率为最高,侵染率分别为80.7%和78.7%;以GV接种和麦糠组合促生效果最为显著,其菌根依赖性达到342.4%,生物量比对照高出278%;该组合促进植株氮素吸收效果也最为显著,其吸氮总量比对照高482%,而以GV接种和腐叶土组合促进枳砧苗磷素吸收效果最为显著,其吸磷总量比对照高466%。适合枳砧容器苗生长的最佳AM真菌和基质组合是GV和麦糠。     

肇庆、云浮市砂糖橘主产区柑橘黄龙病发病率调查研究

对肇庆、云浮市部分砂糖橘果园的柑橘黄龙病进行调查和荧光定量PCR检测,探究该区域柑橘黄龙病的发生和危害情况。结果表明：通过荧光定量PCR检测,所调查的35个果园中,检测出柑橘黄龙病的果园有21个,占60%;受试果园的树龄以6-10年最多,占到了果园总数的60%;柑橘苗木的来源混乱,有网室的无病毒容器苗木为0;采集的14份苗圃样本中,检测出柑橘黄龙病的苗圃有6个,阳性率达42%;果农对柑橘黄龙病认知有限,57%的果农不懂得如何判断黄龙病;果农对柑橘黄龙病的防控措施差。     

Analysis of factors to predict piglet body weight at the end of the nursery phase

In pig (Sus Scrofa) production, within-batch variation in bw gain of piglets during the nursery period (up to 10 wk of age) can be high and is of high economic importance. Homogeneity of BW within batches of animals is important as it influences the efficiency of use of the grower and finisher facilities, and provides an extra value for the fattening farms. In the current study, factors for a light BW at the end of the nursery period of pigs were determined by analyzing datasets from 3 different swine research centers in the Netherlands and France. The entire dataset contained information on 77,868 individual piglets born between 2005 and 2010. Body weight was determined at different time points over the pre- and post-weaning phase, and sex, season of birth, litter information (litter size at day of birth and after cross-fostering, number of piglets born alive per litter, number of total born littermates, sow parity number), cross-fostered animals (yes or no), and pen group size over the post-weaning period were recorded. A risk factor analysis approach was used to analyze the datasets to determine factors that predict piglet bw at the end of the nursery period. Body weight at the end of the nursery period corrected for age was mainly determined by season (P < 0.001), birth weight (BiW, P < 0.001), weaning weight (WW, P < 0.001), and BW at 6 wk of age (P < 0.001). These variables were consistent among datasets and explained approximately 70% of the overall variation in BW at the end of the nursery period. Litter information did not significantly (P > 0.05) contribute to explaining the BW at the end of the nursery period. To discard the possibility of intrauterine growth retarded piglets (IUGR) being the reason for the influence of BiW as an explanatory factor in the regression model, a further analysis was performed on the effect of this category of piglets on the results of the regression analysis. Overall, it was concluded that the bw of piglets at the end of the nursery phase is mainly determined by season, sex, birth, WW, and BW at 6 wk of age. Piglets with a BiW greater than the mean biw minus 2.5 times the sd have the potential to compensate during the subsequent phases of growth.     

Associations between genetics, farm characteristics and clinical disease in field outbreaks of porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory syndrome (PRRS) is a disease of domestic swine characterized by exceptionally high clinical variability. This study addresses the question of whether clinical variability in PRRS results from (a) genetic variation among viral isolates and/or (b) variation in management practices among farms on which isolates are found. Genetic data (open reading frame 5 gene sequences) and data on farm characteristics and associated clinical disease signs were collected for 62 PRRS virus (PRRSV) field isolates, representing 52 farms. Clinical disease signs were interrelated — confirming that a true reproductive syndrome exists (involving abortions, infertility in sows, deaths of sows and preweaning mortality).

Pairs of farms experiencing deaths in their sow populations also tended to share viral isolates which were more similar to one another than expected by chance alone. This implies that sow death (one of the more-severe manifestations of PRRS) is under genetic influence. Large herd size was a significant risk factor for the death of sows and for respiratory disease in nursery pigs. All-in–all-out management practices in the nursery were protective against reproductive signs in the sow herd. All-in–all-out management practices in the finishing stages of production were protective against respiratory disease in nursery pigs — but were paradoxically associated with an increased risk of infertility in sows. These results suggest that farm-management practices can also influence which PRRS clinical signs are manifested during an outbreak. In general, signs associated with PRRS appear to result from a combination of genetic factors and herd-management characteristics. The relative contributions of these two influences differ depending on the specific clinical sign in question.     

草炭对野古草容器苗生长和萌芽的影响

野古草(Arundinella hirta(Thunb.)Tanaka)是近年新开发的多年生草本园林植物,需要培育合格的容器苗以满足园林绿化施工的要求。于是,在2008年2月-2009年5月研究草炭与园土不同配比的基质对野古草容器苗生长和越冬萌芽的影响。结果表明:在野古草容器苗培育的不同阶段(15 cm营养钵和30 cm营养钵)对基质的要求不同,在5 cm营养钵培育时期,可以采用草炭含量33%~100%的基质,在30 cm营养钵培育时期,适宜采用草炭含量50%~67%的基质;应用WinRHIZO根系扫描系统分析不同基质中野古草的根系,根系的总长度、总表面积和总体积随着基质中草炭含量的增加而增加;园土中添加草炭改善了基质的理化性质,含水量、田间持水量、总孔隙度增加,容重降低,从而促进野古草容器苗根系的生长发育,植株株高、冠幅、分蘖数、花序数、生物量等均增加;基质中草炭含量和覆盖处理影响种苗的越冬萌芽;纯草炭作为基质延迟萌芽。覆盖处理提高了基质的含水量、温度等,使容器苗的越冬萌芽率达到100%。     

不同基质对枳容器苗生长的影响

为了筛选适宜枳砧木繁育的基质,研究了本土、椰糠、草炭、有机肥的23种配比组合对枳容器苗生长的影响。结果表明,基质处理S15（本土：椰糠：草炭：有机肥=7：2：0：1）能提高枳苗木的茎粗、株高和地下部分干重,分别比CK高出67.40%、86.79%和82.05%;基质处理S7提高了植株根总长、根表面积和根体积,分别比CK高出51.30%、31.58%和31.35%;基质处理S11提高了地上部分鲜重和地上部分干重,别比CK高出309.95%和207.14%;基质处理S14提高了枳苗木地下部分鲜重,比CK高出了82.05。综合考虑成本、效益,筛选出S15（本土：椰糠：草炭：有机肥=7：2：0：1）处理为枳苗繁育的最适基质配方。     

放牧家畜养分消化率的测定

放牧家畜养分消化率反映牧草供给量和营养品质、家畜的健康状况以及生产性能等，是草原管理的关键指标之一。放牧家畜养分消化率的测定方法主要有直接测定和间接估测两种，直接法包括全收粪法、指示剂法、近红外光谱法（NIRS）等，间接法主要有体内或体外发酵法、牧草品质和气候等预测法。全收粪法是较精确的测定方法，然而耗时、费力，对家畜放牧行为有较大影响，难以体现牧场饲草供给的空间异质性；指示剂法根据不溶物的回收比例估测养分消化率，对家畜放牧行为干扰较小，指示剂不易收集，也不适于野性较高的放牧动物；NIRS法效率高、劳动强度低、成本小、不影响家畜，能够大尺度地估测放牧家畜的养分消化率，需要大量的实测数据完善预测模型；气候估测法快捷、省时，精确性较差，适于大时空尺度。放牧家畜的养分消化率与家畜、草地、放牧方法、温度、降水等生物因子，环境因子和社会因子密切相关，与遥感、无人机（UAV）和人工智能等结合，可以准确、快速地测定放牧家畜养分消化率，为草地生态修复与健康管理提供支撑。     

蛋壳品质营养调控的研究进展

蛋壳不仅可以作为对鸡蛋内容物的支撑、免受外力的侵害,还能保护鸡蛋内部成分免遭微生物的侵袭。蛋鸡生产中常出现蛋壳破损等问题,据统计,全世界由蛋壳质量而导致的损失达6%~10%,我国每年因此也造成5亿多元的损失。因此,提高蛋壳质量是蛋鸡行业亟须解决的重要问题之一。近年来,学者从营养调控方面已开展了大量研究,本文从蛋壳的组成、形成过程、有关因子和调控实践等方面着手,简述国内外在改善蛋壳品质方面的研究进展。     

抗生素工业化生产中一级种子罐染菌原因及解决方法

抗生素工业化生产中,菌种往往需要扩大繁殖到一定的数量后再进入发酵罐.在一级种子制备过程中,引起染菌的因素很多,极大地影响了抗生素生产的产量和质量.解决一级种子罐染菌的方法,除制定科学的岗位SOP并不断提高操作者的技能外,更重要的是要加强工艺管理,树立以预防为主的思想,根据微生物特性,强化环境清洁,加强设备清洁、维修,操作时实行定人、定操作.     

育苗基质和播种方法对蕨菜孢子繁殖的影响

试验采用不同播种方法,比较不同育苗基质对蕨菜孢子萌发和原叶体发育情况的影响。结果表明:70%草炭土+30%细河沙作为育苗基质,蕨菜孢子成苗率较高,为54.3%;喷播法播种效果较好,播种均匀度和成苗数较高。     

The potential contribution of separation technologies to the management of livestock manure

Separation processes have a distinct role in the management of livestock slurries, but it is important to recognise their limitations. Such technology can direct certain manure components into a small volume of a concentrated stream which is useful for the production of organic products in subsequent processes. Equipment generally falls into systems based either on mechanical screening (which can produce a fibrous and seemingly dry product), filtration processes (producing a cake), or sedimentation leading to a sludge product. Although physical separation can remove up to 80% of the total solids content from livestock manures, this will only include a relatively small part of the soluble nutrient and of the reactive organic matter; this is particularly so where separation is based on screens. The complete removal of all suspended matter (total clarification) of an effluent is theoretically possible by settling — a decanter centrifuge will accelerate the process. This can remove most of the phosphorous, especially if coupled with chemical pre-treatment to raise the pH. However, the clarified stream still retains a significant polluting potential in terms of the residual nitrogen content (as ammonia) and potassium. Only membrane separation can greatly reduce the potassium concentration, but such technology is rarely suitable for the farm situation.