水稻植质钵育乳苗栽植机的研制

针对水稻植质钵育乳苗栽植的技术要求,研制出水稻植质钵育乳苗栽植机。以国产延吉六行插秧机为对象,分别对栽植机纵向进给机构、横向进给机构、分秧支撑切割装置、钵苗分秧定位装置和栽植后残屑处理进行了台架试验、组装后整机模拟试验,并连续多年进行了生产性试验,达到了水稻钵育乳苗栽植技术要求,其中：伤秧率1.8%;勾秧率2.0%;漏插率3.2%;均匀度合格率94.6%。为改装其他类型的插秧机提供了参考的技术参数。     

玉米钵苗顶出式有序分秧机构的设计与试验

玉米钵苗移栽可以延长作物生育期,大幅度提高粮食单产和品质。为了解决国际移栽装备结构复杂、成本高、效率低,仅适用于经济作物的问题,该文提出了一种结构简单、成本低、效率高的全自动玉米钵苗移栽机核心工作部件——顶出式有序分秧机构。采用连续输送的纵向送秧方式,设计了并排均布按顺序逐次顶出的分秧形式,分别完成同一排秧苗连续有序的快速顶出。提出了机构相关部件的结构设计参数及设计依据,同时利用渐开线反转法设计了关键部件杠杆的轮廓曲线。完成了该机构的虚拟样机运动学与动力学仿真分析与验证。利用顶出式有序分秧机构进行了玉米钵苗的顶出翻转试验,得出当土钵质量为10 g、秧苗高度为160 mm时钵苗转体高度符合机构设计与栽植要求。利用自制的顶出式有序分秧机构试验台,结合高速摄像技术完成了机构顶出均匀性台架性能试验,验证了该机构性能的合理性;对所研制的试验物理样机进行了田间试验,获得了90.4%的移栽成功率,满足旱地栽植标准,也为开发相关作物的顶出式钵苗移栽机奠定了研究基础。     

水稻钵苗空气整根气吸式有序移栽机的研究

采用空气整根育秧技术对水稻钵苗进行育秧试验，提出了水稻钵苗空气整根育秧、气吸取苗和投苗的有序移栽方案。试验结果表明，采用空气整根培育钵苗，根系遍布整个钵腔，生物学特性优于常规钵育秧，且移栽时钵体不易破碎和倒伏。采用空气整根钵盘，以较小的吸力，钵苗就可从钵腔底部取出，实现不伤苗和根的钵苗有序移栽。对气吸式水稻钵苗有序移栽机的总体方案设计、横纵向移箱装置、投苗装置进行了分析和研究，研制了样机。试验结果表明，由步进电机驱动齿轮齿条机构控制横纵向送秧箱，驱动曲柄摆杆机构控制吸气活门，由电磁铁控制导苗管投苗活门的单     

机械式空气整根钵苗移栽器的研究

空气整根钵苗全自动移栽机的核心部件是移栽器。采用机械方式完成全自动移栽机的送秧和投苗，简化了现有全自动钵苗移栽机的电动或气动送秧和投苗装置，降低了成本。移栽器的性能试验表明，所研制的移栽器性能良好，适应国内市场需要。     

机械式空气整根钵苗移栽器的研究

空气整根钵苗全自动移栽机的核心部件是移栽器。采用机械方式完成全自动移栽机的送秧和投苗，简化了现有全自动钵苗移栽机的电动或气动送秧和投苗装置，降低了成本。移栽器的性能试验表明，所研制的移栽器性能良好，适应国内市场需要。     

华南双季稻区水稻不同机械化栽植方式对比试验与评价

为探索不同机械化栽植方式对华南双季稻区的适应性及其影响机理,2011-2014年连续4 a在广东省肇庆市和江门市,以钵体苗人工手插为对照,安排了钵体毯状苗机插、毯状苗机插和毯状苗窄行机插3种机械化栽植方式的对比试验。应用主效可加互作可乘(additive main effects and multiplicative interaction,AMMI)模型对影响水稻产量的栽植方式、环境和二者的互作进行了分析,进而对不同栽植方式的适应性进行了评价。结果表明:不同栽植方式水稻产量的单因素方差分析显示,3种机械化栽植方式对常规稻都具有良好的适应性,可替代人工手插大面积推广使用;而杂交稻各次试验中3种机插秧栽植方式的产量都低于人工手插,杂交稻机插秧问题还需进一步研究。AMMI分析中,栽植方式平方和、环境平方和及二者的互作平方和分别占处理平方和的6.39%、85.29%和8.31%,都达到了极显著差异水平(P0.01);AMMI模型的交互效应主成分(interaction principal component analysis,IPCA)前2个达到显著水平,两项累计解释了互作平方和的92.99%;残差均方根(root mean square,RMS)的值为49.34 kg/hm2,占总均值的0.71%,表明AMMI2模型对试验的数据结构进行了很好的拟合。适应性评价显示,人工手插的平均产量最高,与环境存在较大正互作,是目前杂交稻种植中最好的栽植方式,但稳定性欠佳;毯状苗机插的平均产量最低,与环境的互作最小,是一种稳定性较好的栽植方式;钵体毯状苗机插的稳定性不及毯状苗机插,但平均产量高于毯状苗机插,与毯状苗机插相比平均增产约-2%~6%;毯状苗窄行机插的稳定性不及钵体毯状苗机插,但平均产量与钵体毯状苗机插相差不大,在杂交晚稻种植中常常高于钵体毯状苗机插。研究结论对推进华南双季稻区种植机械化的发展具有重要参考价值。     

油菜移栽机分苗装置分苗过程与钵苗钵体完整性分析

针对部分分苗装置适应性差、钵体易破损及结构复杂的问题,提出一种输送带式钵苗分苗装置,构建了分苗过程中送苗与分苗阶段的运动学模型,开展了不同挤压方式下的钵体完整性试验,分析得出了输送平稳、钵体完整的条件。结果表明:钵苗在特定基质成份及含水率前提下钵体上边缘最小屈服力为6.8 N,钵体上边缘及侧面受重复挤压力时均有较好的恢复性。钵苗送苗阶段输送平稳性与摩擦系数关系较大,完整性与钵苗自身的屈服力和挤压力有关;钵体在分苗阶段满足完整性前提下,夹持力越大,夹持高度越低,钵苗稳定性越好。分苗合页的动摩擦系数μ1≤0.3375,输送带的动摩擦系数μ2满足0.5μ1μ2≤0.3375,钵苗抗挤压破损力大于1.99 N时,油菜钵苗在送苗阶段可平稳输送且保持完整。该研究为油菜钵苗移栽机结构改进提供了参考。     

半自动压缩基质型西瓜钵苗移栽机设计与试验

针对目前使用压缩基质培育的钵苗无法使用现有移栽机械完成栽植工作的问题,模仿人工先打穴后放苗的移栽方式,设计了一种半自动压缩基质型钵苗移栽机,包含有间歇式打穴装置、持苗栽植装置和钵苗输送装置。通过单因素试验测得2组不同含水率的西瓜钵苗的钵体侧面与滑道的摩擦系数分别为0.755、0.634,并分析了2组钵体抗压载荷与压缩量之间的关系。根据西瓜种植农艺要求及西瓜钵苗外形尺寸,确定了打穴器及钵苗夹持机构的结构尺寸。按照已知运动规律对摆动机构进行优化设计,阐述了持苗栽植装置的工作过程,使用解析法对其进行了运动分析。试验结果表明,拖拉机保持2.1~2.6 km/h的速度前进时,该机作业的平均株距为98.6 cm,株距合格率为90.62%;倒伏率为21.9%,能够基本满足西瓜钵苗移栽的要求。该研究为半自动压缩基质型西瓜钵苗移栽机的设计提供了参考。     

水稻水田栽培史及旱田钵苗机械化移栽新发展研究概述

概述了水稻人工插秧、人工抛秧、机械抛秧、机械毯状苗插秧和机械钵体苗插秧等水田栽培发展史,提出了水稻旱田钵苗机械化移栽新的栽培方式,论证了水稻旱田钵苗机械化移栽的可行性和必要性,公布了水稻旱田钵苗机械化移栽初步研究结果,为水稻产业机械化发展,提供新的栽培方法。     

夹茎式番茄钵苗取苗机构设计与试验

为避免取苗机构在夹取钵苗过程中对钵体与根系造成损伤，该研究针对夹茎取苗方式，提出一种基于二阶椭圆齿轮行星轮系以及凸轮摆杆机构的夹茎式番茄钵苗取苗机构。依据二阶椭圆齿轮传动特性与机构工作原理，建立机构运动学理论模型，并对凸轮轮廓曲线进行设计，结合番茄钵苗取苗作业要求及机构特点，基于MATLAB软件开发机构分析软件对机构参数进行优化，并进一步分析优化后取苗轨迹与凸轮各工作段的对应位置关系，建立了夹茎式取苗机构虚拟样机模型，利用ADAMS软件对取苗机构运动过程进行仿真分析，验证机构参数优化结果及零部件结构设计的准确性与合理性。试制取苗机构物理样机开展高速摄影试验，通过对比分析实际工作轨迹与理论分析及仿真轨迹的一致性，验证了取苗机构设计的正确性。搭建自动取苗试验台进行取苗试验。试验结果表明，取苗机构工作性能可靠、稳定，取苗频率为80株/min时，取苗成功率为92%，投苗成功率为94.2%，伤苗率为2.9%。研究结果可为番茄钵苗全自动移栽机自动取苗机构的研发提供参考。     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.     

细菌、真菌及植物氮营养信号研究进展

氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外（生长介质中）氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。     

Aircraft operations near concentrations of birds in Antarctica: The development of practical guidelines

Aircraft operations have the potential to disturb and to impact negatively on bird life. A gradient of increasing behavioural response is evident in birds when exposed to increasing aircraft stimulus. The most major disturbance is likely to lead to impacts on the health, breeding performance and survival of individual birds, and perhaps bird colonies. A process of revision to policies on aircraft operations contained in management plans for a number of specially protected areas in Antarctica by the United Kingdom, accompanied by consultations made within the scientific community through the Scientific Committee on Antarctic Research (SCAR) and with operational interests through the Council of Managers of National Antarctic Programmes (COMNAP) resulted in new guidelines being adopted by the Antarctic Treaty Consultative Parties in June 2004. The principal recommendations of the guidelines are that bird colonies should not be overflown below 2000 ft (∼610 m) above ground level and landings within 1/2 nautical mile (∼930 m) of bird colonies should be avoided wherever possible. These guidelines are less stringent and less specific than those that were recommended by the SCAR specialist group on birds, and represent a compromise to accommodate operational needs. While the adoption of clear and consistent guidelines for the operation of aircraft in Antarctica is welcome in that this provides practical advice that is likely to reduce incidences of close aircraft/bird encounters, there remains insufficient knowledge of the interactions between aircraft and birds in Antarctica, and the consequent impacts on individual birds and on bird populations. It is important, therefore, that the guidelines adopted are considered interim, and should be kept under scrutiny with revisions made as new and improved research results appear.     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.