江淮丘陵区水稻钾、氮吸收特性与施钾效应研究

江淮地区水稻田间小区施钾效应试验结果表明,施钾能明显提高水稻产量,改善水稻生育性状,在氮磷肥充足时,钾肥的增产效果极其显著。水稻钾吸收量明显以秸秆吸钾量为主,约为籽粒吸钾量的5倍。N来自土壤的数量为120.30 kg hm-2;K2O来自土壤的数量为72.83kg hm-2。NPK全素施钾处理吸钾总量平均高出NP处理48.79%,籽粒和秸秆分别平均增加9.21%和56.8%;说明钾吸收量增加对秸秆产量贡献明显小于对籽粒产量的贡献。除最高施钾量和不施氮处理外,其余处理均出现不同程度钾素亏缺,说明在不施氮肥或氮肥不足的情况下,水稻对肥料钾的吸收量也相应减少。本试验钾肥(K2O)产投比以NPK2处理最高为2.54。综上所述,本地区同等肥力土壤,水稻钾肥推荐用量为120kg hm-2,根据土壤钾素平衡状况,水稻施钾量可适当增加。     

甘肃中部地区砂田西瓜平衡施肥效应及效益研究

在甘肃中部的白银市平川灌区砂田连续3年进行西瓜平衡施肥田间试验研究,结果表明:在本区砂田西瓜采用平衡施肥增产效果明显,且效益显著,在施用一定有机肥基础上,N、P2O5、K2O施用以135kg hm-2、90～135kg hm-2、150 kg hm-2或135:90:150～225的配比较为经济合理,其肥料的产投比达4以上,钾肥合理配施,产投比可达6以上,钾肥净增收益达到5106～5715元hm-2.试验证明,平衡施肥对西瓜的产量和收益比当地习惯施肥增加40%～50%,且可提高作物抗病、抗逆性,改善产品品质,显著提高商品价值.     

钾肥对加工型番茄的肥效研究

田间试验结果表明:在速效K含量150.28mg kg-1的土壤上,番茄N、P、K配合施用比N、P配合施用增产11.56%。番茄产量随K素用量增加而增加,但单位K素增产效果则随K素用量增加而递减。经回归统计分析,K素经济效益最佳施肥量为225kg hm-2时,理论产量为113.53 t hm-2,番茄收入2.84×104元hm-2,肥料成本562.50元hm-2,收益2.78×104元hm-2,增收0.23×104元hm-2。在其它条件基本相同情况下,土壤速效K含量120.40mg kg-1时,每公斤K20增产番茄产品63.87kg;而土壤速效K含量176.26mg kg-1时,每公斤K2O增产番茄产品19.16kg。不同处理间差异显著性经LSR检验达到显著和极显著水平。     

河西走廊制种玉米磷素适宜用量的研究

田间试验结果表明:河西走廊制种玉米NPK配合施用比NK配合施用增产25.30%.玉米产量随P素用量增加而增加,但单位P素增产效果则随P素用量增加而递减.经回归统计分析,P素经济效益最佳施肥量为60.15 kg hm-2时,玉米理论产量为9.75t hm-2,收入2.09×104元hm-2,p肥成本150.00元hm-2,收益2.08×104 元hm-2;在其它条件基本相同情况下,土壤速效P2O5含量5.71mg kg-1的风沙土,每kg P素玉米增产21.17 kg;而土壤速效P2O5含量11.23mg kg-1的灌漠土,每kg P素玉米增产13.50kg.处理间的差异显著性经LSR检验达到显著和极显著水平.     

不同施肥对春玉米源库特征及其关系的影响

采用田间小区试验方法研究了不同氮、磷、钾肥用量对春玉米源、库特征及源库关系的影响.试验设氮、磷、钾肥处理各4个(氮、磷、钾肥用量分别为:N:0、120、240、360kg hm-2;P2O5:0、75、150、225 kg hm-2;K2O:0、120、240、360kghm-2).研究结果表明,当N用量为240kg hm-2、P2O5;用量为150kg hm-2、K2O用量为240kg hm-2时,春玉米的叶绿素含量、叶面积指数、干物质积累量等源特性和穗粒数、百粒重、产量、经济系数等库特性均高于其它处理;表征源库关系的茎鞘物质输出率处于相对较低的水平,粒叶比最低.因此在N、P2O5、K2O用量分别为240kg hm-2、150kg hm-2 240kg hm-2时既可以保持较高的叶源性能,又能促进籽粒库容的增大,能够获得协调的源库关系.     

露地洋葱施肥、土壤养分及产量状况的分析研究

在农户调查和土壤测试相结合的基础上,分析了山东惠民县露地洋葱土壤养分状况、肥料投入及其对产量和养分平衡的影响。结果表明,施用有机肥农户占总调查户的44%,平均由有机肥带入的氮磷钾养分量分别为N 170kg hm-2、P2O5112 kg hm-2、K2O 223 kg hm-2。化肥氮、磷投入量较高,平均分别为N 458 kg hm-2和P2O5399 kg hm-2,是洋葱氮磷吸收量的4.0和6.0倍,化学钾肥不足(K2O 131 kg hm-2),占洋葱钾吸收量的55%。收获时0~30 cm土壤无机氮含量达到88 kg hm-2,O lsen-P(P)和速效钾(K)平均含量分别为25.5和104 mg kg-1。自春季返青前到收获期间,30~60 cm和60~90 cm土壤无机氮含量均有不同程度的提高,土壤氮表观损失量与氮素投入量呈显著直线相关,维持土壤氮素平衡的最大氮素供应量为290 kg hm-2。相关分析表明,无论是氮、钾化肥投入量还是各阶段土壤无机氮、速效钾含量都与洋葱产量无显著相关,而磷肥用量及0~30 cm土壤剖面O lsen-P含量与产量有显著正相关(p<0.05)。     

4种忍冬属(Lonicera)植物花粉的形态比较

田间试验表明:各种施肥配方对夏芝麻产量影响由大到小的顺序依次为NP>K>N>P,高肥力田块,目标产量为1110.0kg hm-2,氮肥经济合理施用量为N106.5 kg hm-2,磷肥经济合理施用量为P2O552.5kg hm-2;中肥力田块,目标产量1011.0kg hm-2,氮肥经济合理施用量为N129.0kg hm-2,磷肥经济合理施用量为P2O5117.0 kg hm-2;低肥力田块,目标产量759.0 kg hm-2,氮肥合理经济施用量为N147.0 kg hm-2,磷肥经济合理施用量为P2O564.5 kg hm-2。氮肥以底追结合和二次追施方式效果最好,比对照增产34~35%。,叶面肥增产幅度为7.7~10.4%,以喷磷酸二氢钾和喷硼效果最好。该项研究取得了显著的经济效益和社会效益。     

皖南红黄壤地区连续施用磷钾肥对油菜产量、养分吸收及土壤肥力的影响

在皖南红黄壤地区利用大田试验研究了连续施用磷钾肥对油菜产量、养分吸收和土壤肥力的影响。结果表明:在施用氮肥的基础上合理配施磷钾肥,促进了油菜的生长发育,提高了油菜植株的养分含量和养分吸收量,从而显著增加了油菜的产量,并且磷肥的增产效应大于钾肥效应,三季油菜平均产量以处理P90K120最高,达到了1968.7 kg hm-2;同时连续施用磷钾肥能够改善土壤养分含量,显著提高了土壤速效钾、速效磷含量,与试验前土壤相比,速效磷增加了14.83~20.2 mg kg-1,速效钾增加了69.51~109.61 mg kg-1。     

氮、磷、钾肥配施对WL-232HQ苜蓿品种鲜草产量及营养成分的影响

2003年在内蒙古西辽河平原灰色草甸土上采用"3414"二次回归最优设计设计试验方案,研究N、P、K肥配施对WL-232HQ紫花苜蓿(Medicago sativa)当年草产量和营养成分的影响,结果表明:施N 27.36kg hm-2,施P2O5 54.71kg hm-2,施K2O 281.33 kg hm-2时可获得鲜草最高产量77976.9kg hm-2.14个处理组合中,初花期以处理4(N2P0K2)和处理12(N2P1K1)粗蛋白的含量高;初花期的粗纤维含量小于25.0%的处理组合是处理8(N2P2K0)和处理10(N2P2K3),均达到国家一级标准[9];初花期粗灰分含量处理1(N0P0K0)和处理9(N2P2K1)较低;并分析了N、P、K肥对WL-232HQ紫花苜蓿营养成分的影响.     

氮磷钾不同配比对饲用稻威优198产量及糙米蛋白含量的影响

采用田间小区试验研究“推荐配比”(N:P2O5:K2O比率为190:90:100 kg hm-2)、“高氮量配比”(N:P2O5:K2O比率为210:90:100 kg hm-2)、“低氮量配比”(N:P2O5:K2O比率为170:90:100 kg hm-2)以及“常规配比”(N:P2O5:K2O比率为216:112.5:202.5 kg hm-2)4种氮、磷、钾配比施肥对饲用稻威优198蔗糖合成酶(SUS)、腺苷二磷酸焦磷酸化酶(AGPase)、硝酸还原酶(NR)、谷氨酰胺合成酶(GS)以及产量和糙米蛋白质的影响。结果表明:“推荐配比”能提高不同生育时期水稻功能叶(旗叶)和粒籽中碳、氮代谢关键酶的活性,这些关键酶活性的变化显著影响水稻产量和糙米全氮以及蛋白氮的含量。统计(P0.05)结果证实“推荐配比”能提高水稻产量达到8200 kg hm-2,与“常规配比”相比产量提高了24.81%;“推荐配比”糙米全氮和蛋白氮含量分别达到22.70 g kg-1和21.98 g kg-1,与“常规配比”相比差异显著,并且其全氮和蛋白氮含量分别提高17.01%,18.38%。     

奶牛产奶量性状相关基因知识图谱的研究与构建

奶牛生产性状中产奶量一直是相关领域专家重点关注的性状之一,产奶量的提高对于经济和民生发展具有重要意义,因此产奶量的相关影响因素成为了研究提高奶产量和奶质量的焦点。针对目前缺少奶牛产奶量-基因知识图谱的问题,以PubMed生物医学文献库为相关来源,利用爬虫技术构建奶牛产奶量性状组学数据的相关文献数据集,通过知识抽取获得与奶牛产奶量相关的大约140个基因影响因素及其他影响因素。利用Neo4j图数据库的方式进行数据存储,构建与奶牛产奶量性状相关的知识图谱,最后形成奶牛产奶量性状数据知识库的可视化平台。     

Usefulness and limits of MODIS GPP for estimating wheat yield

Gross primary productivity (GPP) estimates derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) are converted to wheat yield and compared with observed yield for counties, climate districts and entire states for the 2001 and 2002 growing seasons in Montana and North Dakota. Analyses revealed that progressive levels of spatial aggregation generally improved the relations between estimated and observed wheat yield. However, only state level yield estimates were sufficiently accurate (? 5% deviation from observed yield). The statewide yield results were encouraging because they were derived without the use of retrospective empirical analyses, which constitutes a new opportunity for timely wheat yield estimates for large regions. Additionally, this study identifies six practical limits to estimating wheat yield using MODIS GPP. As a result we describe three suggestions for improving wheat yield estimates for scientists willing to re‐compute MODIS‐derived GPP estimates using regionally specific inputs.     

Processes controlling sediment yield from watersheds as functions of spatial scale

The need for estimates of sediment yield are ubiquitous throughout water resources analyses, modelling, and engineering as sediment is a major pollutant, a transporter of pollutants, and sedimentation rates and amounts determine the performance and life of reservoirs, canals, drainage channels, harbors, and other downstream structures and improvements. Moreover, as a ‘watershed wide’ measure of soil erosion, transport, and deposition, sediment yield reflects the characteristics of a watershed, its history, development, use, and management.The major factors and processes controlling sediment yield from watersheds are described and discussed in the context of spatial scale. Historical sediment yield data from selected watersheds across a range of scales are used to illustrate variations of sediment yield with watershed scale. Generalized relationships between sediment yield and drainage area from the USA and Australia are used to show the statistical variations of sediment yield with watershed area. Area is shown to be an important predictor variable which usually, but not always, is correlated with sediment yield.Experimental data from a small experimental watershed are used in a case study to illustrate processes controlling sediment yield. The case study summarizes and interprets simulation model studies using experimental field data from measurements distributed across a range of scales. Information presented here should help guide the conceptual development of sediment yield models and their mathematical formulation. It should also be useful in design and implementation of spatially distributed verification and validation studies.     

Shakedown analysis of circular plates using a yield criterion of the mean

Structural optimization based on the shakedown theory is a powerful and promising technique. However, due to the nonlinearities of physical materials and the number of variable loads in real structures, it is computationally complex and time-consuming. To simplify the occurring non-linear, non-convex optimization problems, the paper suggests reducing the number of yield conditions. The so-called a yield criterion of the mean (integral yield condition) is analysed and explained in detail, which allows taking into account one yield condition for the entire finite element instead of multiple point-wise conditions. This approach shows promising results in numerical application to the optimization of a circular plate, considering a possibility of employing the yield criteria of the mean or pointwise yield conditions in different areas of the plate in particular. The methods applied are based on the assumptions of perfect plasticity and small deformations.     

Fast prediction and optimization of yield in gallium arsenide large-signal MMICs

A study on the effects of the geometrical and physical parameters of the GaAs MMIC process on the yield of large-signal circuits is presented. Large-signal yield analysis as well as large-signal yield optimization are performed using a large-signal lumped-element MESFET model related to MMIC process parameters, and suitable for implementation in commercial microwave CAD tools. The characterization of all the statistical variables of a large-signal circuit provides a better understanding of the yield behavior. In particular, the sensitivity of large-signal yield to MMIC process parameters is computed and the statistical behavior of each parameter is presented by means of yield sensitivity histograms. © 1998 John Wiley & Sons, Inc. Int J RF and Microwave CAE 8: 68–76, 1998.     

CHA杂种小麦生长发育及产量优势特性形成的研究

以 ＣＨＡ杂种及其亲本为材料，探讨了 ＣＨＡ杂种小麦产量优势形成过程的生长发育特点以及不同组合优势性状及其大小，从不同角度阐述了 ＣＨＡ杂种小麦产量优势形成的原因。     

水稻遥感气象估产数据库设计

详细介绍了水稻、遥惑估产研究中气象估产数据库设计的思路与技巧，以及各类数据库的结构、相互间的关系，并阐述了它们在运行系统中的作用，为各专题分析应用和系统软件开发提供了基础性和结论性的数据和成果。     

Usefulness of spectral reflectance indices as durum wheat yield predictors under contrasting Mediterranean conditions

Early prediction of crop yield can be an important tool for identifying promising genotypes in breeding programmes. To assess whether measurements of canopy reflectance at given stages of development could be used for yield forecasting and to identify the most appropriate indices, locations and growth stages for durum wheat yield assessment, nine field experiments, each including 20 or 25 durum wheat (Triticum turgidum L. var durum) genotypes, were carried out under a wide range of Mediterranean conditions. Canopy reflectance was recorded with a portable field spectroradiometer at several times from booting to physiological maturity, and nine indices were further derived. Grain yield was measured at harvesting. The results indicated that milk-grain stage was the most appropriate developmental stage for yield assessment. However, some indices were also sensitive to yield variations when determined at anthesis or even heading or booting. The capacity of spectral reflectance indices to forecast grain yield increased on locations that allowed genotypes to express their yield potentiality. Reflectance at 550?nm (R550), water index (WI), photochemical reflectance index (PRI), structural independent pigment index (SIPI), normalized difference vegetation index (NDVI) and simple ratio (SR) explained jointly a 95.7% of yield variability when all the experiments were analysed together, 92% being explained by R550. When regression analyses were carried out separately for each experiment, spectral reflectance indices explained from 17.3% to 65.2% of total variation in yield, and the indices that best explained differences in yield were experiment-dependent. Our data suggest that reflectance at 680?nm (R680), WI and SR may be suitable estimators of durum wheat grain yield under Mediterranean conditions, when determined at milk-grain stage.     

CAD for statistical analysis and design of microwave circuits

Statistical circuit design is essentially a method of design for reliability and high yield. For all but the smallest circuits, this is a CAD problem. Within this problem there are three subproblems: design centering, tolerance assignment, and variability reduction. This paper concentrates on design centering. Yield optimization is inherently a difficult problem because yield cannot, in general, be calculated exactly; only estimates of the yield are available. Furthermore, yield gradients are not available when some yield estimation techniques are used. This paper presents a review of useful definitions using parameter space concepts. Yield estimation techniques and some of their properties are also presented. The two distinct yield optimization strategies commercially available today, statistical and deterministic, are each discussed in detail. Examples of each are given.     

Yield estimation and forecasting for winter wheat in Hungary using time series of MODIS data

Wheat is one of the most important crops in Hungary, which represents approximately 20% of the entire agricultural area of the country, and about 40% of cereals. A robust yield method has been improved for estimating and forecasting wheat yield in Hungary in the period of 2003–2015 using normalized difference vegetation index (NDVI) derived from the data of the Moderate Resolution Imaging Spectroradiometer. Estimation was made at the end of June – it is generally the beginning of harvest of winter wheat in Hungary – while the forecasts were performed 1–7 weeks earlier. General yield unified robust reference index (GYURRI) vegetation index was calculated each year using different curve-fitting methods to the NDVI time series. The correlation between GYURRI and country level yield data gave correlation coefficient (r) of 0.985 for the examined 13 years in the case of estimation. Simulating a quasi-operative yield estimation process, 10 years’ (2006–2015) yield data was estimated. The differences between the estimated and actual yield data provided by the Hungarian Central Statistical Office were less than 5%, the average difference was 2.5%. In the case of forecasting, these average differences calculated approximately 2 and 4 weeks before the beginning of harvest season were 4.5% and 6.8%, respectively. We also tested the yield estimation procedure for smaller areas, for the 19 counties (Nomenclature of Territorial Units for Statistics-3 level) of Hungary. We found that, the relationship between GYURRI and the county level yield data had r of 0.894 for the years 2003–2014, and by simulating the quasi-operative forecast for 2015, the resulting 19 county average yield values differed from the actual yield as much as 8.7% in average.