基于15N 示踪的酿酒葡萄氮素营养需求分析          下载免费PDF全文

蒋婷婷  闫鹏科  于茹  马婷慧  王锐 《中国土壤与肥料》2022,(8):165-171

植物在不同时间对氮素营养的需求迥异,为掌握宁夏贺兰山东麓酿酒葡萄氮素分布特征和营养需求规律,以7 年生“赤霞珠”为研究对象,每株施氮255.10 g(15N- 硫酸铵10 g+ 普通硫酸铵245.10 g)。利用15N 同位素示踪技术,在施氮后35、70、105、140 和160 d 采集土壤和酿酒葡萄根、茎(茎分为主干、一级分枝、二级分枝)、叶、果,对其15N 丰度和全氮量进行测定分析。计算不同时间各器官肥料中吸收分配到的15N量对该器官全氮量的贡献率(Ndff)、分配率、氮肥利用率、残留率以及损失率。结果表明:根、主干、一级分枝、二级分枝、叶和果的干物质量均在施氮后70 ～ 105 d 明显增加,施氮后105 d 的干物质量较施氮后70d 分别增加了95.19%、4.23%、6.51%、58.58%、30.00% 和219.84%。在施氮后70 ～ 105 d,根、主干、一级分枝、二级分枝、叶和果的Ndff 值明显上升,施氮后105 d 的Ndff 值较施氮后70 d 分别增加了6.38、5.89、5.87、7.25、4.34 和7.01 个百分点。根的15N 分配率在施氮后35 d 高于其他施氮时期,为1.46%。主干、一级分枝和二级分枝的15N 分配率均在施氮后160 d 高于其他施氮时期。根、主干、一级分枝、二级分枝、叶和果的15N 分配率在施氮后70 ～ 105 d 均明显增加,施氮后105 d 的15N 分配率较施氮后70 d 分别增加了5.26、0.52、0.24、2.55、3.70 和3.21 个百分点。综上所述,酿酒葡萄在施氮后70 ～ 105 d 为氮素吸收峰值期,在此期间应注重氮肥的施入。整个施氮时期酿酒葡萄的氮肥利用率为38.97%,氮肥残留率为17.77%,氮肥损失率为43.25%。  相似文献   

基于热重法的生物质工业分析及其发热量测定   总被引：3，自引：3，他引：0  

王茹  田宜水  赵立欣  姚宗路  孟海波  侯书林 《农业工程学报》2014,30(5):169-177

为了比较不同种类生物质的燃烧特性,丰富热重分析技术的应用方向,该文采用热重分析技术对农业剩余物、林业剩余物和工业加工废渣的代表性生物质进行了空气气氛下不同升温速率的燃烧特性试验研究。研究表明:3种类型生物质的燃烧过程均包括4个主要阶段:水分蒸发阶段、挥发分析出及燃烧阶段、固定碳燃烧阶段、燃尽阶段。该文提出1种确定样品工业分析值的方法,即热分析曲线法,并推荐应用20℃/min升温速率下的热分析曲线图来计算确定。同时还提出1种差热分析法,用以计算生物质样品发热量,分析发现,农业秸秆类剩余物适用于20℃/min的升温速率,木屑和甜高粱渣适用于5、10℃/min的升温速率。该文提出的计算工业分析值的热分析曲线法与计算发热量的差热分析法,为热重分析技术研究生物质的燃烧特性提供了新的应用方向,但2种新方法的建立,以及他们的有效性和适用性,仍需要大量试验数据的验证和进一步的试验研究。  相似文献   

Characterization of DMI,QoI and SDHI fungicides sensitivity of Ramularia collo-cygni isolates in Argentina     

Erreguerena  Ignacio Antonio  Havis  Neil David  Heick  Thies Marten  Gorniak  Kalina  Quiroz  Facundo  Carmona  Marcelo Anibal 《植物病害和植物保护杂志》2022,129(6):1343-1353

Journal of Plant Diseases and Protection - Ramularia leaf spot (RLS) caused by the fungus Ramularia collo-cygni (Rcc) has become a threat to barley production in Argentina. All barley varieties are...  相似文献   

The transfer of heavy metals to barley plants from soils amended with sewage sludge with different heavy metal burdens     

José Martín Soriano-Disla  Ignacio Gómez  José Navarro-Pedreño  Manuel M. Jordán 《Journal of Soils and Sediments》2014,14(4):687-696

Purpose

Our main aim objective was to evaluate the transfer of Cd, Cr, Cu, Ni, Pb and Zn to barley (Hordeum vulgare) grown in various soils previously amended with two sewage sludges containing different concentrations of heavy metals. This allowed us to examine the transfer of heavv metals to barley roots and shoots and the occurrence of restriction mechanisms as function of soil type and for different heavy metal concentration scenarios.

Material and methods

A greenhouse experiment was performed to evaluate the transfer of heavy metals to barley grown in 36 agricultural soils from different parts of Spain previously amended with a single dose (equivalent to 50 t dry weight ha^?1) of two sewage sludges with contrasting levels of heavy metals (common and spiked sludge: CS and SS).

Results and discussion

In soils amended with CS, heavy metals were transferred to roots in the order (mean values of the bio-concentration ratio in roots, BCF_Roots, in brackets): Cu (2.4)?~?Ni (2.3)?>?Cd (2.1)?>?Zn (1.8)?>?Cr (0.7)?~?Pb (0.6); similar values were found for the soils amended with SS. The mean values of the soil-to-shoot ratio were: Cd (0.44)?~?Zn (0.39)?~?Cu (0.39)?>?Cr (0.20)?>?Ni (0.09)?>?Pb (0.01) for CS-amended soils; Zn (0.24)?>?Cu (0.15)?~?Cd (0.14)?>?Ni (0.05)?~?Cr (0.03)?>?Pb (0.006) for SS-amended soils. Heavy metals were transferred from roots to shoots in the following order (mean values of the ratio concentration of heavy metals in shoots to roots in brackets): Cr (0.33)?>?Zn (0.24)?~?Cd (0.22)?>?Cu (0.19)?>?Ni (0.04)?>?Pb (0.02) for CS-amended soils; Zn (0.14)?>?Cd (0.09)?~?Cu (0.08)?>?Cr (0.05)?>?Ni (0.02)?~?Pb (0.010) for SS-amended soils.

Conclusions

Soils weakly restricted the mobility of heavy metals to roots, plant physiology restricted the transfer of heavy metals from roots to shoots, observing further restriction at high heavy metal loadings, and the transfer of Cd, Cu and Zn from soils to shoots was greater than for Cr, Ni and Pb. Stepwise multiple linear regressions revealed that soils with high sand content allowed greater soil-plant transfer of Cr, Cu, Pb and Zn. For Cd and Ni, soils with low pH and soil organic C, respectively, posed the highest risk.  相似文献   

Equilibrium information from nonequilibrium measurements in an experimental test of Jarzynski's equality   总被引：1，自引：0，他引：1  

Liphardt J  Dumont S  Smith SB  Tinoco I  Bustamante C 《Science (New York, N.Y.)》2002,296(5574):1832-1835

Recent advances in statistical mechanical theory can be used to solve a fundamental problem in experimental thermodynamics. In 1997, Jarzynski proved an equality relating the irreversible work to the equilibrium free energy difference, DeltaG. This remarkable theoretical result states that it is possible to obtain equilibrium thermodynamic parameters from processes carried out arbitrarily far from equilibrium. We test Jarzynski's equality by mechanically stretching a single molecule of RNA reversibly and irreversibly between two conformations. Application of this equality to the irreversible work trajectories recovers the DeltaG profile of the stretching process to within k(B)T/2 (half the thermal energy) of its best independent estimate, the mean work of reversible stretching. The implementation and test of Jarzynski's equality provides the first example of its use as a bridge between the statistical mechanics of equilibrium and nonequilibrium systems. This work also extends the thermodynamic analysis of single molecule manipulation data beyond the context of equilibrium experiments.  相似文献   

黄河中游骨干坝蓄水比例及蒸损量研究     

胡娟萍  张丽  赵茹  陈学凯 《中国农村水利水电》2015,(7)

近年来,受到气候的极端变化和各种人类活动的影响,黄河中游径流量减少的趋势越来越明显。在以往的水资源评价中,只考虑了干流上部分水库对径流减少的影响,而忽略了蓄水骨干坝的影响。通过水土保持部门调研、Google Earth查询以及实地勘测等途径,较为准确的确定了骨干坝的分布及蓄水比例,并根据水量平衡得出蓄水骨干坝的蒸发损失。研究表明:黄河中游头道拐至潼关之间,骨干坝共计4 798座,包括蓄水骨干坝895座,蓄水比例达到18.65%;骨干坝蒸损量为0.19亿m3。此研究初次考虑了蓄水骨干坝对径流减少的影响,可为以后研究径流减少提供理论依据。  相似文献   

Relationships between available soil water and indicators of plant water status of sweet sorghum to be applied in irrigation scheduling   总被引：3，自引：0，他引：3  

Ružica Stričevič  Endre Čaki 《Irrigation Science》1997,18(1):17-21

Optimal crop production depends greatly on available soil water, and it is therefore important to know when and how much to irrigate in order to attain agronomic potential. In this work, plant indicators are used to assess water stress. These are compared with available soil water to find the critical point for irrigation scheduling of sweet sorghum. The experimental trial was carried out in Bečej, in the Vojvodina region, on a sweet sorghum crop, grown in moderate climatic conditions on a well-drained, deep chernozemolic meadow soil. Plant indicators tested were predawn and midday leaf water potential and crop and air temperature difference. All the methods were sensitive to water deficit in plants, but not all can be used for irrigation scheduling. The predawn leaf water potential was the most reliable parameter among those tested due to its relative independence from weather conditions and a valid indicator of plant water status. This was not the case with canopy-air temperature difference. The predawn leaf water potential corelation with available soil water indicates that the threshold value for irrigation scheduling of sweet sorghum is when the former has decreased to –0.45 MPa. This corresponds to a soil water depletion to about 10% of available water in the active root zone. The canopy-air temperature difference was sufficiently sensitive to indicate the onset of mild plant water stress, although it showed a certain threshold value when water shortage appeared, which occurred when the air and canopy temperature were the same. Received: 9 April 1996  相似文献   

黄土高原土壤粒径分形特征及其对土壤侵蚀的影响   总被引：8，自引：0，他引：8  

茹豪  张建军  李玉婷  杨宗儒  冯换成 《农业机械学报》2015,46(4):176-182

采用单重和多重分形方法分析晋西黄土丘陵沟壑区土壤粒径分布特征、不同土地利用类型对土壤粒径分形参数的影响以及分形参数与土壤粒径分布之间的关系。结果表明:黄土高原不同地区的土壤粒径分布不同,采用激光法测定的土壤粒径分布在粉粒域和砂粒域内,需要通过优化来重新确定粘粒域、粉粒域和砂粒域3个尺度域的界线。通过测定得出研究流域内土壤粒径分布在20~100μm较为狭窄的范围内,呈现明显的非均匀性,需要采用多重分形来表述其分布特征。粉粒域维数Dsilt与粘粒和粉粒的体积分数呈极显著正相关关系(P0.01),而砂粒域维数Dsand与砂粒体积分数呈负相关关系且不显著,可以利用Dsilt预测土壤质地的变化和不同土地利用类型遭受侵蚀的程度。不同土地利用类型对土壤粘粒、粉粒、砂粒的体积分数以及粉粒域维数Dsilt、容量维数D0、信息维数D1和信息维数与容量维数的比值D1/D0有极显著影响(P0.01),对砂粒域维数Dsand有显著影响(P0.05),表明可用多重分形参数作为反映土地利用类型对土壤物理性质影响的指标。  相似文献   

Development of predictive models to explain the distribution of the West Indian manatee Trichechus manatus in tropical watercourses     

Ignacio Jiménez 《Biological conservation》2005,125(4):491-503

Logistic regressions were used to study the relationship between habitat variables and the use of tropical watercourses by the West Indian manatee Trichechus manatus at Northeastern Costa Rica and Southern Nicaragua. Presence of manatees in watercourses was assessed through direct and reported sightings of individuals and feeding signs on aquatic vegetation. Indirect methods provided good approximations to the actual distribution that could not have been achieved through direct observations or aerial surveys. Best multivariate models showed that manatees were most present in watercourses that presented abundant aquatic vegetation, warm, and clear waters, high forest cover, and are wider than those where the species is absent. Although habitat variables that explain habitat use of manatees differed for the two sectors found within the study area, manatees preferred lagoons to other watercourses in both areas. These findings point to forest clearing on the shores as a threat for manatee conservation. Habitat variables are excellent predictors of manatee presence, and predictive models as those developed in this study can help assess potential distribution of manatees in areas where this information is lacking as well as to assist identify potential reintroduction areas.  相似文献   

基于模拟模型的棉花生产管理系统研究   总被引：4，自引：2，他引：4  

邱建军  肖荧南  戴逸民  胡锡宁  王茹  林海 《农业工程学报》2002,18(6):161-164

为建立一个基于模型的新疆和黄淮海棉区棉花生产管理系统(MSCP),综合运用了作物模拟技术和知识工程技术方法,把CottonPlus棉花模型与多因子多水平的旋转组合设计进行有机结合;MSCP能对决策地区(天气、土壤、品种特性)的棉花生产作出多目标决策和全程决策,并根据变化的条件作出实时决策。应用MSCP对新陆早6号、中棉19号进行全程决策试验,结果表明:系统得出的优化农艺措施能达到预期的目标产量。MSCP的建立使基于模型的专家系统研究进入实用化阶段  相似文献