Analysis of a Long-term Experiment with Repeated-measurement Models

Long‐term experiments are a classical case of repeated measurements. Traits are measured on the same experimental unit over many years so that correlations arise between the observations made on the same plot in consecutive years. This paper describes the analysis of a three‐crop‐rotation long‐term experiment. We analysed the yields of the crops and the organic carbon content in the topsoil over 30 consecutive years. Several variance–covariance approaches are discussed and the trait‐specific best fit is interpreted. Mixed models are used to describe the structure of the experiment. Both yields and soil organic carbon show a more or less pronounced variance heterogeneity. Especially for yields, the heterogeneity of cycles and years is dominant. The consideration of correlations results in a better model fit in all cases.     

黑龙江省水稻生产现状与前景展望

黑龙江省是中国最北部一年一季高寒稻区,得天独厚的有利自然资源极适于发展水稻生产。由于历史原因,1955~1983年面积一直徘徊在13.7万~24.55万hm2,单产2535.0~4482.0kg/hm2,在中国属面积少、单产不高、变幅较大的低产稻区。1984年推广旱育稀植后,栽培技术发生重大变革与发展,但单产仍然较低,1985~1994年10a间平均只有4744.77kg/hm2。为此,1995~1998年针对黑龙江省生产现状开展了“水稻大面积高产综合技术研究与示范”,3a攻关研究结果,每年平均面积39.93万hm2,占同期全省平均面积135.62万hm2的29.4%,获平均7893.0kg/hm2,较试验前五年全省平均5748.57 kg/hm2,增产37.3%,比同期全省平均增产32.9%,为黑龙江省进一步大面积增产树立了榜样和增强了信心。研究还针对当前生产现状,论述了今后发展黑龙江省水稻生产前景及其实现高产与之相关的有效途径。     

A Predictive Method of Index on Power Consumption in a Resident Unit

In this paper, a series of data on power consumption and the numbers of household appliance in a resident unit of a district, were analyzed by regression technique. A curve of the index on power consumption of a resident unit in a district has been gained. This curve was tested by another series of data obtained at the same time.     

样品制备对转基因抗虫棉外源Bt蛋白定量检测的影响

采用ELISA(Enzyme-linked immunosorbent assay)方法,以转Bt基因抗虫棉品种中棉所45(ZGK 9822)和鄂抗虫棉1号(GK 19)为研究材料,对叶片的不同组织、同一样品不同的冻存时间和同一样品不同研磨程度的Bt蛋白进行定量检测。结果表明:叶片不同组织Bt蛋白表达量差异较小,叶脉Bt蛋白表达量略高于叶肉和叶柄的Bt蛋白表达量;转基因抗虫棉单位鲜物质质量Bt蛋白含量和单位可溶性总蛋白Bt蛋白含量随着冻存时间的延长而降低,鄂抗虫棉1号单位鲜物质质量Bt蛋白含量冻存90 d样品与冻存30 d、60 d样品差异显著,单位可溶性总蛋白Bt蛋白含量无显著差异;不同研磨程度对转基因抗虫棉单位鲜物质质量Bt蛋白含量和单位可溶性总蛋白Bt蛋白含量都存在影响,其中差异最大的为鄂抗虫棉1号,200目试样比50目试样单位鲜物质质量Bt蛋白含量上升了56%,单位可溶性总蛋白Bt蛋白含量上升了38%。     

东北三省粮食生产区域变化及影响因素分析

为了研究东北三省粮食生产区域变化及其影响因素,通过克里金空间插值法分析了1995年和2010年东北三省粮食单产和总产的空间格局及其变化情况,并对粮食单产区域差异的影响因素进行多元回归分析。结果表明：东北三省的粮食单产及总产都表现为由中部高值区向四周不断减少的格局,2010年与1995年相比粮食单产的高值中心由中部向西北部移动,粮食总产高值区域范围变大。从粮食单产的区域差异因素分析结果来看,在粮食单产降低区域,受灾比例升高、有效灌溉比例下降及单位面积农业劳动力升高是引起粮食单产降低的主要原因;在粮食单产升高区域,受灾比例下降、单位面积化肥使用量增加及单位面积农业劳动力降低等都对粮食增产有积极作用。     

Computation of heat unit accumulations in maize for practical application

Summary Every year maize breeders are facing the problem of trying to synchronize flowering of strains, hybrids and varieties to be crossed. Sowing in stages of one of the partners is the method most applied. In general this method gives good results, but there are years, such as 1954, when synchronization according to this method does not produce the results desired. The author discusses the possibilities to use heat unit accumulations for the synchronization of flowering of strains, hybrids or varieties to be crossed mutually.Sowing time trials over a number of years, conducted by the C.I.L.O. and the S.V.P. procured the data for the computations of the heat unit accumulations. Computations are made for threshold values of 0, 5, 7 and 10°C. It appeared that not all treatments have a similar threshold value, but that there are no great differences. In general they are approaching temperatures of 7 to 10°C.On assuming too low a threshold value the heat unit accumulations will appear to be too high, because temperatures are included which do not influence the development. This effect will be more prominent when more of these temperatures occur, for instance in a cold year or a year when sowing has taken place at an earlier date. In consequence the total of the heat unit accumulations can be seen to decrease, according as it is computed in a warm year or for a later sowing date. Conversely the heat unit accumulations will appear to be too low when a high temperature is assumed.If the precise threshold value is accounted for, the heat unit accumulation is equal, apart from the year or date of sowing.In 1955 a complete synchronization of the flowering of W 85 x W 15 and W 9 x WD was obtained by sowing them with such an interval as was indicated by the difference in the heat unit accumulations sowing-flowering in 1954. The computation of these heat unit accumulations was carried out on the basis of both air- and soil temperatures. It appeared that the air-temperatures alone are sufficient, provided sowing is done on the same type of soil as the previous year.A more accurate heat unit accumulation can be computed from the addition of the heat unit accumulation sowing-emergence (soil temperatures) and emergence-flowering (air temperatures).     

The application of TDR in laboratory column experiments

An automated TDR system was used together with an automated tensiometer system in laboratory column experiments for the measurement of unsaturated hydraulic properties of soils. The laboratory experiments were a stationary flux (sprinkling infiltrometer) carried out with different fluxes, and a transient (evaporation) method. Simultaneous measurements of water content and pressure head give the water retention characteristic and enable the application of the instantaneous profile analysis for calculating the hydraulic conductivity. This direct analysis is compared with the traditional analysis methods normally used for the laboratory experiments. The application of automated measurement techniques and the use of TDR increases the speed of the measurements, generates more data points and requires less assumptions in the data analysis. Moreover, TDR measurements give insight in the flow process, including effects of hysteresis and heterogeneity within a sample. Performing the sprinkling infiltrometer and evaporation experiments on the same sample enables the determination of the unsaturated hydraulic conductivity at pressure heads ranging from −0.01 m to −6 m.     

Spatial variability of root zone soil water status and of fertilizer N uptake by forage crops

Spatial variability of a field soil was studied using a neutron probe to measure soil water status of the plant root zone, and isotopically labelled fertilizers to evaluate fertilizer nitrogen uptake. The work was carried out long three 96 m transects with 63 plots each, the first being bare soil, the second planted to rye grass and the third planted to alfalfa.Autocorrelation and crosscorrelation analysis were used to evaluate spatial dependence of the measurements. Field variability in soil water content measurements was found to be space dependent over a distance of 6 m and this implied that size of sampling domain for water content measurements could be 12 m for the experimental field. The spatial variability measured in atmospheric nitrogen fixation of alfalfa showed rather close resemblance to the spatial variability observed in water content measurements and was related to spatial variability of available soil nitrogen. The main assumption made when the ¹⁵N methodology is used is that the ratio of percentage N derived from fertilizer over percentage N derived from soil is the same for the non-fixing reference crop and the fixing crop. Based on measurements made on ryegrass which was used as a reference crop to assess the nitrogen fixation potential of alfalfa, it was found that under these particular field conditions this ratio was space dependent with a zone of influence of 6 m, suggesting that the maximum distance between rye grass plots and its counterpart alfalfa plots could only be 6 m.The results are discussed in the context of improvement of field experimental designs.     

用微卫星DNA标记分析苎麻品种的亲缘关系

用3种微卫星标记分别分析了20个苎麻品种的DNA。每种标记方法都能在苎麻品种间产生多态性的谱带。ISSR每个检测单位产生的DNA条带最多,平均每个引物对扩增出8个DNA条带;其次是RAMP。虽然SSR每个检测单位产生的条带数最少,但其扩增图谱中,87.0%的条带是多态性条带,高于ISSR和RAMP。ISSR和RAMP扩增图谱中多态带的频率分别     

组合播种方式对小麦群体及产量形成的影响

为了提高玉米秸秆还田后小麦播种质量,为广大麦玉轮作区小麦生产提供技术支撑,通过采用将不同小麦播种方式进行组合的研究方法,对小麦群体发育及产量结构进行分析。结果表明：在播量相同情况下,“撒播+宽幅播”的组合播种方式可以显著降低田间缺苗断垄单元的分布,提高田间群体生物量积累。通过试验研究得出：在适宜播量条件下,“撒播+宽幅播”的组合播种播量比例以1:2为宜。‘舜麦1718’在播量为135.0 kg/hm²时,播量比例为1:2的“撒播+宽幅播”的组合播种方式,产量显著高于传统条播、宽幅播及撒播等单一播种方式。     

Two Types Modules for the Boiler Attached to 330 MW Unit

Boiler is an important facility in power plant , the safety and economy of unit is affected by it. Studying the dynamic of boiler can improve the knowledge about boiler , which is important for. Features of MMS are introduced based on MMS simulation setting, and the real time capable module and non real time capable module are compared from principle. Real time capable dynamic model of boiler and non real time capable dynamic model of boiler of 330 MW unit are established . The experimental results show that the dynamic process of two type model accords with the mechanism of the object , at the same time, the validity of real time capable module is discussed .     

Nitrogen status and biomass determination of oilseed rape by laser-induced chlorophyll fluorescence

Site-uniform nitrogen fertilization can lead to local over- or under-supply of nitrogen on heterogeneous sites. Suitable sensor solutions are needed to perform on-the-fly measurements of the local N-requirement. Sensor systems already in use to this end in agricultural practice are based on light reflectance measurements.By contrast, a measurement principle based on laser-induced two-wavelength chlorophyll fluorescence (LICF) presents some major advantages given that the measurement signals originate only from plant material. The LICF measurement principle measures the chlorophyll fluorescence induced by red laser light at 630 nm at wavelengths of 690 nm and 730 nm. The ratio of the two wavelengths correlates strongly with aboveground N content, with statistical analysis of measurement data providing biomass information. Thus, both N content and biomass can be determined simultaneously using this technology.This work tested the accuracy of this measurement principle in determining N content and biomass of oilseed rape in field trials. LICF measurements were compared to reflectance-based measurements, both of which were referenced against conventionally determined values for N content and biomass dry weight.Our results show that the N status and aerial biomass dry weight determination by LICF measurements are possible with the same accuracy as with the conventional determination. Furthermore, it could be shown that the LICF measurement allows for the determination of biomass independent of the N content. The good performance of LICF-based protocols in determining local N content and biomass supports their potential utility in site-specific fertilizer application.     

转型期作物生产发展的机遇与挑战

中国作物生产正处于由传统手工劳动为主的小规模生产向机械化、集约化、信息化程度高的适度规模化生产过渡的转型期。在此期间, 作物生产发展的重要目标是实现单位耕地生产率与人均劳动生产率的同步提高。近年来, 中国作物生产能力的稳步提高、生产方式的重大转变以及工业经济的迅速发展为转型期作物生产发展创造了新的机遇, 但同时也带来了新的挑战, 涉及多熟制作物生育期缩短、大田生产用种量增加和杂种优势利用价值下降等方面。针对上述挑战, 笔者从发展密植高光效栽培、提高杂交作物种子质量以及加强育种与栽培协同攻关等方面展望了转型期作物生产的研究方向。     

平房仓横向通风技术在玉米储藏上的应用研究

为了研究平房仓横向通风技术在玉米储藏上的应用效果,明确玉米储藏过程横向通风工艺及其参数,利用高大平房仓中设计安装的横向通风设施,以及在储藏玉米粮堆中预埋的插入式毕托管,对高大平房仓横向通风系统进行实仓测试。全面开展了玉米储藏过程中横向通风工艺应用研究,测试了在横向通风系统通风时,风速、风量、系统各部分阻力和粮堆压力分布。研究发现,在储藏玉米的高大平房仓中应用横向通风系统时,粮堆单位粮层阻力较小,在实用单位通风量时,横向通风系统总阻力不大于1200Pa;同时横向通风还具有风量分配均匀、粮堆通风均匀性良好的特点。该研究为玉米在配备横向通风系统的高大平房仓储藏提供了技术支持。     

湿养条件下红萍产量与能耗的关系研究

【研究目的】通过不同人工光源能耗下湿养红萍的产量试验,明确红萍湿养产量与人工光源能耗之间的关系。【方法】在自行研制的红萍湿养栽培装置上,利用T4荧光灯设置3个不同的光强范围,并在相同湿养空间下设计5个不同的光源配置方案进行红萍湿养的产量比较试验。【结果】单位湿养面积下,红萍表面光照强度在6000-7000Lux时产量最高,单位能耗日产鲜萍量也最高,过低（3000-4000Lux）和过高的光强（9000-10000Lux）都会影响红萍产量和单位能耗日产鲜萍量的提高;红萍湿养的产量与扎入湿养介质根的数量和长度呈显著正相关;同一湿养空间下,降低层间距,减少荧光灯使用数量,可以提高能耗转化产量的效率。【结论】相同湿养空间下,保持红萍表面光照强度在6000-7000Lux,通过适当增加层数或者降低层间距来调整人工光源配置以达到降低能耗的目的,可以实现以较低能耗获得较高产量的效果。     

湖南水稻干旱评估方法研究

为了探讨双季早稻、双季晚稻、一季稻干旱影响定量评估方法,统计各熟制水稻各生育期综合气象干旱指数、水分亏缺指数与水稻受旱率、成灾率、单位面积粮食减产量的相关,分析各熟制水稻干旱影响敏感期;基于相关系数,定量计算综合气象干旱指数、水分亏缺指数组合成综合评估指标所占的权重,组建各熟制水稻旱情综合评估指标;基于各熟制水稻旱情综合评估指标,结合抗旱能力,通过多元回归建立各熟制水稻受旱率、成灾率、单位粮食减产量评估模型。结果表明：（1）湖南季节性干旱特征明显,对于双季晚稻,各生育期干旱出现频率基本接近,干旱影响期为返青分蘖期和幼穗形成期;双季早稻、一季稻各生育期干旱出现频率差异较大,以水稻生长后期干旱出现频率高,而水稻干旱影响敏感期也在水稻生长后期。（2）双季早稻干旱灾害评估模型历史同级拟合率平均为77.6%,级差一级以下的拟合率为91.1%;双季晚稻同级拟合率为70.9%,级差一级以下的拟合率为83.0%;一季稻同级拟合率为61.8%,级差一级以下的拟合率为84.5%。基于降水、需水、可供水等因子建立水稻干旱灾害评估模型,物理意义清楚,准确率较高,可为水稻干旱影响定量评估提供技术支持。     

Photosynthetic and respiratory response of potato leaves of different ages during and after an episode of high temperature

Little is known about net photosynthetic rates (Pn) of potato during and after the end of a high-temperature episode. We investigated Pn of potato leaves exposed to a high-temperature episode. Plants were grown in the greenhouse at 22°C. Shortly after tuber initiation, plants were transferred to 30°C for 9 days and then returned to 22°C. High temperatures reduced Pn of older leaves but not of the youngest leaves. Effects were transitory; Pn of leaf 7 initially fell, but then increased to be higher than the control plants. High temperature increased respiration per unit area during the night and morning relative to the control plants. Leaves that emerged during the 30°C episode had higher Pn than the control plants when returned to 22°C. Results emphasise that it is not possible to use single-leaf measurements to infer effects on photosynthesis throughout the canopy. Similarly, the diurnal variation in effects on respiration means that Pn measurements made only at midday are inadequate. Finally, the dynamic response of Pn to the high temperature and the persistent effects after the end of the episode mean that the impact of high-temperature episodes cannot be extrapolated from experiments using constant temperature treatments.     

Stärke- und Amylosesynthese in Samen von Mark- und Futtererbsen

Changes of clay soils under organic and conventional farming
Chemical, mineralogical and soil-physical measurements were performed on clay soils, which were cultivated under conventional and organical production system for the last 14 years. Soils in the organic system [TNL soils] were loosened from 10–35 cm and organic residues and manure were incorporated into the 0–10 cm layer by a rotowator. Soils in the conventional system [TKL soils] were plowed to a depth of 22 cm. Humus and nitrogen reserve and the amount of mobile phosphate in the top soils of the TNL soils were higher than in those of the TKL soils. The exchangeable potassium in the top soil was higher in TKL soils than in TNL soils, whereas the organic system (TNL) showed a more equal distribution within top and subsoil. This observation was confirmed by measurements of the mobile potassium (ARo-values).
The contents of 2:1 layer silicates with expanded layers was lower in the top soil of TKL soils than in TNL soils. This can be explained by the reduced application of liquid manure (Gülle) and the missing application of potassium fertilizer on TNL soils. The layer charge of the expanded minerals ranged from -0.80 to -0.68 for the vermiculites, and from -0.45 to -0.35 for the smectites, per formula unit respectively.
No influence on the percentage of the fine and mid pores was found. The amount of slow draining large pores (Ø 50-10 μm) was higher in TNL soils than in TKL soils, only in a neighbouring pasture soil the proportion of these pore exceeded those of TNL soils. Measurements of pore continuity did not show such a clear difference between TKL and TNL soils, but was higher for TNL soils.     

优质蛋白玉米产量和品质性状配合力、杂种优势及相关分析

以3个优质蛋白玉米自交系（♀）和5个优质蛋白玉米自交系（♂）为试验材料,按照NCⅡ遗传交配设计组配成15个杂交组合,对其主要性状的配合力、杂种优势及其间相关进行分析。结果表明：①同一性状不同材料间,同一材料不同性状间其配合力效应表现复杂,存在不同效应大小和正负作用方向的差异,父本A粒深、容重的一般配合力均较高;母本2赖氨酸含量的一般配合力较高;组合3×C容重的特殊配合力较高。②小区产量与粒深、穗粗呈极显著正相关;赖氨酸含量与粗脂肪含量呈极显著正相关,与粗蛋白含量呈显著正相关。③赖氨酸含量、粗蛋白含量以超低亲杂种优势为主;粗淀粉含量以超中亲优势为主;粗脂肪含量以超高亲优势为主。     

数据缺失下基于单位线的流量模拟应用

[目的]针对降雨径流模拟过程中的数据缺失现状,[方法]基于不同雨型的数据缺失特征构建不同的数据缺失模式,采用不同的插值方法构建单位线,探讨不同缺失模式下的单位线推广应用。[结果][结论]结果表明,采用不同插补方法构建得到单位线的末端拟合效果较好,对峰值的插补效果不佳。不同雨型插补后的峰值位置存在偏离现象,基于峰值偏离现象和单位线倍加原理得到单位线峰值后在进行插补得到单位线的拟合效果较好,为无资料地区的降雨径流模拟和农业非点源评估模拟提供了新的理论思考,具有较好的推广意义。