基肥与密度互作对水稻产量构成因素及产量的影响     

任淑娟  柴楠  焉山 《北方水稻》2019,49(3):23-26

采用随机区组法,以三江6号和绥粳18号为试验材料,研究基肥与密度互作对产量构成及产量的影响。结果表明:两个品种基肥与密度处理间在穗数、穗粒数、结实率、千粒重及产量上均存在互作关系,A3B3(20 kg/667 m^2基肥,30cm×12 cm)组合有利于水稻产量的提高,A1B1(12 kg/667 m^2基肥,30 cm×16 cm)组合不利于水稻产量的提高。  相似文献   

基于大数据的化学基础与分析技术在线课程建设     

黄秀锦  谭佩毅 《农业科技与装备》2019,(2):90-92

从大数据的视角,以高职食品类专业化学基础与分析技术在线课程建设为切入点,在教学内容、教学模式、考核评价等方面进行改革实践与探索,为建设化学基础与分析技术在线课程打下基础,对同类在线课程建设具有借鉴作用。  相似文献   

Does the “high sugar” trait of perennial ryegrass cultivars express under temperate climate conditions?     

M. Jordana Rivero  Oscar A. Balocchi  Cristian J. Moscoso  Juan Agustín Siebald  Fabin Lukas Neumann  Don Meyer  Michael R. F. Lee 《Grass and Forage Science》2019,74(3):496-508

The objective was to evaluate water‐soluble carbohydrate (WSC) and crude protein (CP) concentration of perennial ryegrass (PRG) cultivars with different genetic potential for producing WSC under two contrasting agronomic managements in temperate climate (southern Chile). A 4 × 2 factorial design was randomly allocated to 24 plots (31 m² each, three blocks): four PRG cultivars (diploid standard cultivar, “2nSt”; tetraploid standard cultivar, “4nSt”; diploid high sugar cultivar developed in New Zealand, “2nHSNZ”; and tetraploid high sugar cultivar developed in Europe, “4nHSEU”) and two agronomic managements (“favourable,” defoliations at three leaves per tiller and nitrogen (N) fertilization rate of 83.3 kg N ha^?1 year^?1; “unfavourable,” defoliations at two leaves per tiller and N fertilization rate of 250 kg N ha^?1 year^?1). Herbage samples were collected in early spring, spring, summer and autumn. Concentration of WSC did not differ among cultivars in spring and summer, averaging 194 and 251 g/kg DM, respectively. The cultivar 4nHSEU had the greatest WSC concentration in early spring and autumn (187 and 266 g/kg DM, respectively) and the greatest CP concentration across samplings (average 230 g/kg DM). Favourable management improved WSC concentrations in early spring and summer and decreased CP in spring, summer and autumn. Annual DM yield did not vary with cultivar or management, averaging 8.43 t/ha. Within a 12‐month study at one site in a temperate environment in southern Chile, PRG cultivars have not shown a consistent expression of the “high sugar” trait, where a genetic × environment interaction might be operating.  相似文献   

水稻高产高效的根-冠互作机制研究进展   总被引：2，自引：1，他引：1  

陶荣荣  蔡晗  朱庆权  周益雷  王康平  余超  侯丹平  刘海浪  张耗 《中国农学通报》2018,34(5):1-4

为了全面认识水稻高产与水分养分高效利用的过程及其生物学机理,塑造高产高效的冠层和根系,本文归纳了高产高效水稻的根系形态和生理特征,总结了高产高效水稻的群体质量、物质生产特征及叶片光合特性,并分析了高产高效水稻根-冠互作的方式和指标。针对水稻水肥利用率低的问题,本文提出了通过协调根-冠互作机制来协同实现水稻的高产高效,并对水稻高产高效的根-冠互作机制研究进行了展望。  相似文献   

水氮互作对冬小麦光合生理特性和产量的影响   总被引：7，自引：3，他引：4  

王磊  董树亭  刘鹏  张吉旺  赵斌 《水土保持学报》2018,32(3):301-308

针对黄淮海地区农业生产中存在的水资源供应短缺,肥料利用率低等问题,设计试验研究水氮互作对冬小麦光合生理特性和产量的影响,为黄淮海地区高效利用水氮资源提供理论依据。2015-2017年以石麦15(SM15)为材料,利用水肥渗漏研究池,设计2个供水量水平(500,250 mm);2个施氮量水平(90,180kg/hm~2);2个氮肥类型(无机肥尿素,有机肥牛粪)。结果表明:2年试验内冬小麦旗叶光合生理特性变化规律相似,各处理的冬小麦旗叶光合速率,蒸腾速率,单叶水分利用效率在生育期内均呈现先上升后下降的趋势。水氮互作对小麦旗叶光合速率影响显著,W1(供水量500mm)处理的旗叶光合速率明显高于W2(供水量250mm)处理,施氮肥180kg/hm~2处理的旗叶光合速率明显高于施氮肥90kg/hm~2的处理,与施用无机肥相比,施用有机肥可保证冬小麦生育后期维持较高的旗叶光合速率。2年试验干物质积累量最多、产量最高的处理为W1M1(供水量500mm,施有机氮肥180kg/hm~2)。综合冬小麦光合生理特性,籽粒产量,本试验条件下有机肥增产效果优于无机肥,冬小麦生育期供水量500mm,施有机氮肥180kg/hm~2时冬小麦旗叶光合生理特性较优,获得较高产量。  相似文献   

Effects of fragmentation on the seed predation and dispersal by rodents differ among species with different seed size          下载免费PDF全文

Qiong CHEN  Kyle W. TOMLINSON  Lin CAO  Bo WANG 《Integrative zoology》2017,12(6):468-476

Fragmentation influences the population dynamics and community composition of vertebrate animals. Fragmentation effects on rodent species in forests may, in turn, affect seed predation and dispersal of many plant species. Previous studies have usually addressed this question by monitoring a single species, and their results are contradictory. Very few studies have discussed the fragmentation effect on rodent–seed interaction among tree species with different seed sizes, which can significantly influence rodent foraging preference and seed fate. Given that fruiting periods for many coexisting plant species overlap, the changing foraging preference of rodents may substantially alter plant communities. In this study, we monitored the dispersal and predation by rodents of 9600 seeds, belonging to 4 Fagaceae species with great variation in seed size, in both the edge and interior areas of 12 tropical forest fragments ranging in area from 6.3 to 13872.9 ha in Southwest China. The results showed that forest fragmentation altered the seed fates of all the species, but the intensity and even the direction of fragmentation effect differed between species with large versus small seeds. For the seeds harvested, fragment size showed negative effects in forest interiors but positive effects at edges for the 2 large‐seeded species, but showed little effect for the 2 small‐seeded species. For the seeds removed, negative effects of fragment size only existed among the small‐seeded species. The different fragmentation effect on seed dispersal and predation among plant species may, in turn, translate into the composition differences of the regeneration of the whole fragmented forest.  相似文献   

Pathogenic nature of Syncephalastrum in Atta sexdens rubropilosa fungus gardens          下载免费PDF全文

Mariana O Barcoto  Felipe Pedrosa  Odair C Bueno  Andre Rodrigues 《Pest management science》2017,73(5):999-1009

  相似文献   

An experimental study on the influences of wind erosion on water erosion   总被引：1，自引：0，他引：1  

Huimin YANG 《干旱区科学》2017,9(4):580-590

In semi-arid regions, complex erosion resulted from a combination of wind and water actions has led to a massive soil loss and a comprehensive understanding of its mechanism is the first step toward prevention of the erosion. However, the mutual influences between wind erosion and water erosion have not been fully understood. This research used a wind tunnel and two rainfall simulators and simulated two rounds of alternations between wind erosion and water erosion(i.e., 1~(st) wind erosion–1~(st) water erosion and 2~(nd) wind erosion–2~(nd) water erosion) on three slopes(5°, 10°, and 15°) with six wind speeds(0, 9, 11, 13, 15, and 20 m/s) and five rainfall intensities(0, 30, 45, 60, and 75 mm/h). The objective was to analyze the influences of wind erosion on succeeding water erosion. Results showed that the effects of wind erosion on water erosion were not the same in the two rounds of tests. In the 1~(st) round of tests, wind erosion first restrained and then intensified water erosion mostly because the blocking effect of wind-sculpted micro-topography on surface flow was weakened with the increase in slope. In the 2~(nd) round of tests, wind erosion intensified water erosion on beds with no rills at gentle slopes and low rainfall intensities or with large-size rills at steep slopes and high rainfall intensities. Wind erosion restrained water erosion on beds with small rills at moderate slopes and moderate rainfall intensities. The effects were mainly related to the fine grain layer, rills and slope of the original bed in the 2~(nd) round of tests. The findings can deepen our understanding of complex erosion resulted from a combination of wind and water actions and provide scientific references to regional soil and water conservation.  相似文献   

椭圆柱绕流摆动流固耦合的数值模拟     

李涛  王玉川  亢阳  赵聪聪  宋晓倩 《排灌机械工程学报》2018,36(4):307-312

为了分析不同影响因素对椭圆柱绕流摆动规律的影响,采用计算流体动力学——刚体动力学耦合模型进行椭圆柱绕固定轴摆动的双向流固耦合数值模拟.通过求解二维非定常不可压缩黏性流体N-S方程和SST k-ω湍流模型控制方程,研究不同长短轴比(0.6, 0.8, 1.0),不同偏心距离比(0, 0.2, 0.4, 0.6, 0.8)和不同雷诺数(3 900, 5 000, 10 000)的椭圆柱绕流的流动特征,分析了不同工况下椭圆柱绕流的运动和流动规律.结果表明,椭圆柱的摆动角度θ随着长短轴比和雷诺数的增大而增大,随着偏心距离比的增大先增大后减小;椭圆柱的摆动频率和雷诺数呈良好的线性递增关系,但长短轴比和偏心距离比对椭圆柱的摆动频率影响不明显.分析了椭圆柱绕流的尾流演变以及瞬时压力系数的变化,揭示了椭圆柱绕流摆动的机理,为利用椭圆柱开发海洋海流能和低水头水能资源提供了依据.  相似文献   

Iron and manganese effect on soil chemical properties,yield components,and nutritional status of soybean     

A. Moreira  L. A. C. Moraes  G. S. Aquino 《Communications in Soil Science and Plant Analysis》2018,49(15):1844-1854

In plants, iron (Fe) and manganese (Mn) have many functions, as the transport and electron transference during photosynthesis, and their deficiencies affect the chlorophyll formation, plant growth and grain yield (GY). We carried out two experiments under greenhouse conditions with the aim of determining the influence of Fe and Mn on nutritional status, physiological components, soil chemical properties and yield components of soybean plants. In both experiments, five Fe and Mn rates were used. The GY, shoot dry weight yield (SDWY), the number of grain per pot (NGP), photosynthesis rate (A) and chlorophyll content were influenced by Fe rates, while GY, SDWY, root length and A were influenced by Mn rates. Iron and Mn concentrations in leaves and grains increased with rates of Fe and nutrients. The Mehlich 1 and DTPA-TEA extractants were efficient to determine the Fe and Mn available in the soil.  相似文献