番茄锌营养临界值的研究

在盆钵条件下,试验布置在褐土菜园土和草甸土菜园土上。试验表明:施锌量与土壤有效锌含量和植株体内含量呈线性关系。根据这些数量关系计算出育苗阶段两种土壤有效锌缺锌临界值分别为5.32、9.80ppm,致害临界值分别为10.61、28.09ppm,生长在两种土壤上番茄幼苗锌缺锌临界值分别为55.73、65.98ppm,致害临界值分别为81.05、124.11ppm,开花阶段两种土壤有效锌缺锌临界值分别为11.32、13.89ppm,致害临界值分别为16.35、31.95ppm,生长在两种土壤上的番茄植株体内锌缺锌临界值分别为59.71ppm和81.43ppm,致害临界值分别为82.53ppm和124.11ppm。     

不同滴灌春小麦品种的氮素吸收规律和氮营养指数

为探究滴灌春小麦氮素吸收规律和不同生育时期氮营养状况的基因型差异,以新春6号和新春35号为供试材料,设置0、75、150、225、300、375kg·hm-26个施氮水平,分析滴灌条件下不同春小麦品种在生育期内的氮素吸收曲线、临界值曲线及氮营养指数。结果表明,两个春小麦品种氮素吸收量均随施氮量的增加而增加,新春6号的氮素快速积累期早于新春35号。植株吸氮量的临界值与出苗后天数均呈极显著的二次函数关系(新春6号:y=-0.174 6x2+22.528x+414.02,R2=0.998**;新春35号:y=-0.169 9x2+20.832x+357.13,R2=0.993**)。依据氮营养指数计算,两个春小麦品种的适宜施氮量均在225~300kg·hm-2范围,且应适当降低出苗后25d之前和提高出苗后35d的施氮量。     

几种高大禾草热值和灰分动态变化研究

对3种C₃类植物(芦竹、菅、芦苇)与5种C₄类植物(五节芒、芒、岗柴、斑茅、南荻)不同器官热值和灰分含量的月变化进行了研究,并探讨了其应用前景,为禾草类能源植物筛选评价提供科学依据。结果表明,1)8种高大禾草灰分含量存在差异,且具明显的季节性变化;C₃类植物平均灰分含量分别为:芦竹(7.17±1.09)%、菅(6.33±0.60)%、芦苇(7.89±1.09)%;C₄类植物平均灰分含量分别为:五节芒(4.92±1.38)%、芒(6.27±0.94)%、岗柴(6.99±1.13)%、斑茅(5.13±0.88)%、南荻(5.10±0.82)%。2)C₃类植物中芦竹干重热值较高,C₄类植物中五节芒、芒、斑茅、南荻的干重热值比较接近,无显著差异,岗柴干重热值最低。3)芦竹的干重热值与灰分含量有显著线性相关(P＜0.05),五节芒、芦苇的干重热值与灰分含量有极显著线性相关(P＜0.01),而菅、芒、岗柴、斑茅、南荻的干重热值与灰分含量无相关性(P＞0.05)。4)C₃类植物平均去灰分热值分别为:芦竹(19.01±0.27)kJ/g、菅(18.58±0.31)kJ/g、芦苇(18.72±0.23)kJ/g;C₄类植物平均去灰分热值分别为:五节芒(18.52±0.32)kJ/g、芒(18.69±0.47)kJ/g、岗柴(18.54±0.33)kJ/g、斑茅(18.48±0.41)kJ/g、南荻(18.49±0.37)kJ/g,灰分含量不同,导致去灰分热值与干重热值的月变化趋势不同。     

Sensitivity,specificity, and predictive values of reagent test strip estimations of blood urea nitrogen

Azostix-reagent-tests(R) strips (Ames, Miles, Inc., Diagnostic Division, Elkhart, IN) were used to measure blood urea nitrogen values in blood samples from 125 dogs and cats at the North Carolina State University, College of Veterinary Medicine. Results of the tests were compared with standard serum urea nitrogen results. Sensitivity, specificity, and negative predictive values were high (86.4, 90.3, and 96.5%, respectively). Positive predictive value was low, 65.5% of the dogs and cats with elevated blood urea nitrogen values were correctly classified as abnormal The test performs well when the prevalence of abnormal values is near 50%.     

不同阶段矮小型褐壳蛋鸡血液生理生化指标测定

试验测定20、40、60周龄矮小型褐壳蛋鸡血液生理指标、血清生化指标,每一周龄公、母鸡各9只,样本量为54只。将数据进行t检验及多重比较分析,结果表明,在此3个时间点上,指标RBC、HGB、MPV、PDW、LYMF%、TP和CHO呈现上升趋势,指标HCT、MCV、RDW%、WBC、LYMF值是先下降后上升,而MCH、MCHC、PCT、PLT、MID、MID%、GRAN、GRAN%、AST、ALB、TG、GLU和ALT值是先上升后下降。同时,不同周龄鸡之间在血液生理生化指标上表现出不同项目差异显著(P0.05)。20、40及60周龄矮小型褐壳蛋鸡雌、雄间均存在显著差异(P0.05)的血液生理生化指标有RBC、HCT、HGB、WBC、LYMF和AST,这表明矮小型褐壳蛋鸡的生理和生化指标随周龄不同,在雌、雄之间的差异随之发生变化。     

The cultural model of “the good farmer” and the environmental question in Finland

Farmers' relationship with nature isdetermined by the significance of agriculturefor human beings. When agriculture is definedas human activity that uses renewable naturalresources and aims to produce usable food andfiber products, agriculture is explicitlydefined as production. Farmers' relationshipwith nature is based on the principle ofproduction. This article discusses thecontradiction between the peasant values ofprotection of nature that many farmers inFinland still have and the environmental harmtheir production-oriented farming style causes.When farmers interpret their farming practicesas harmonious co-operation with nature, it isdifficult for them to see the polluting effectsof their work. Paul B. Thompson's suggestionthat three religious–philosophical doctrines(hard work, the doctrine of grace, and the mythof garden) have made it easy for farmers toadopt productionist farming strategy is used asa framework to interpret farmers' narrativesconcerning their relationship with nature. Theresearch is qualitative and biographical. Thedata include life stories and biographicaltexts farmers wrote for a competition in1997.     

奎屯河流域土地利用/覆被及生态系统服务功能变化

[目的]分析25年来奎屯河流域土地利用/覆被与生态系统服务功能的变化,以期为该区域资源管理和生态经济协调发展提供理论基础.[方法]在3S技术的支持下,以1975年和2000年的TM 图像解译数据为基础,采用谢高地的评价方法分析了25年来奎屯河流域土地利用/覆被与生态系统服务功能的变化特征.[结果]1975～2000年,奎屯河流域耕地、城乡建设用地、盐碱地和沙地有所增加,其他林地、草地、水域和沼泽的面积均减少;区域生态系统服务功能从1975年的3 108.68×106元减少到2000年的2 953.91×106元,减少量为154.77×106元,减少率为4.98;;[结论]生态系统服务价值降低说明该区域生态环境趋于恶化,将来区域发展必须加强生态环境保护力度.     

Citrus leaf nutrient status: A critical evaluation of guidelines for optimal yield in Israel

Maintaining orchards with trees at optimal leaf nutrient concentrations is one of the key issues for maximizing yield. Experiments for evaluating and updating guidelines are very rare since they require several years of field experiments with mature fruit‐bearing trees. In the present paper, we first evaluated the Israeli guidelines for citrus by comparing them to the Israeli orchard leaf mineral status using a 10‐year leaf‐mineral database (results of 20 244 leaf analyses from commercial orchards all over Israel). Then, we created an updated guideline using a second database (the Israeli National Wastewater Effluent Irrigation Surveys database; INWEIS). This database summarizes yield and leaf mineral concentrations of commercial orchards from all over Israel. The data were collected from 122 orchards: 39 orchards of “Oroblanco” Pomelit (Citrus grandis), 33 orchards of “Michal” mandarin (C. reticulata), 30 orchards of “Star Ruby” grapefruit (C. paradise), and 20 orchards of “Shamouti” oranges (C. sinensis) over a 7‐year period. Based on the first database, there was a disagreement between recommendations and the leaf nutrient status (e.g., the Israeli Ministry of Agriculture recommendations were higher than orchard median values), which indicated that the growers and/or the recommendations need to be corrected. Based on the INWEIS database, a new guideline was set. It was found that the optimal leaf nutrient concentrations for grapefruit trees are 1.7% to 2.1% dry weight (DW) for N, 0.08% to 0.010% DW for P, 0.37% to 0.48% DW for K, and 0.33% to 0.45% DW for Mg. For orange trees, the optimal leaf nutrient concentrations are 1.9% to 2.3% DW for N, 0.11% to 0.14% DW for P, 0.80% to 1.00% DW for K, and 0.19% to 0.26% DW for Mg. For mandarin trees, the optimal leaf nutrient concentrations are 2.0% to 2.4% DW for N, 0.09% to 0.12% DW for P, 0.55% to 0.69% DW for K, and 0.19% to 0.26% DW for Mg. Maintaining leaf nutrient concentrations within these ranges will support maximal yields of 110 to 120 t ha^–1 for grapefruit, 65 to 70 t ha^–1 for orange, and 60 to 70 t ha^–1 for mandarin cultivars.     

中国梦视阈下农民生态价值观的构建

“中国梦”是国家的梦、民族的梦,也是每一个中国人的梦.“中国梦”的提出,对于当前农民生态价值观的构建提出了全新的要求,用“中国梦”引领新时期农民价值观的取向,构建科学的生态价值观,对于我国社会主义现代化建设具有重要意义.在分析当前农民生态价值观现状的基础上,该文从“中国梦”视角探析“中国梦”与农民生态价值观构建之间的关系,阐释农民生态价值观构建的基本途径.     

Prediction of breeding values for osseous fragments in fetlock and hock joints, deforming arthropathy in hock joints, and pathologic changes in the navicular bones of Hanoverian Warmblood horses

The results of a standardised radiological examination of 5928 Hanoverian Warmblood horses selected for sale at auction were used to predict relative breeding values (RBV) in the 23,662 horses included in the last four generations of the probands' pedigrees. The distribution of the RBV was investigated in the whole four-generation pedigree, in the probands and in those stallions that contributed at least three offspring to the probands. The RBV of the probands' sires were further compared with the officially published performance-based relative breeding values, i.e., total indices dressage (TID) and jumping (TIJ). The sires' level of dressage indices was considerably higher (mean TID=110) than of the jumping indices (mean TIJ=98). Total indices radiographic findings (TIR) were calculated for the sires with varying weighting given to the individual RBV. In each case, this resulted in a mean TIR of 99. Finally, total indices were derived from TIR and TID and/or TIJ in order to develop different selection schemes for all-purpose breeding and for breeding focused on dressage and show jumping. All breeding values under consideration increased by between 1% and 19% when radiographic findings were weighted with between 30% and 60% complementary to the corresponding performance parameters, and when only sires were selected with above average total indices. At the same time, the prevalences of the radiographic findings investigated here were lowered by up to 10% each. When only one radiographic finding was considered at a time, the maximum attainable response to selection was a 16-23% increase in the relative breeding values and a relative decrease in prevalences of radiographic findings of between 31% and 52%. The results of this study indicate that it is possible in horse breeding to consider simultaneously health and performance traits. Medical data should be included in the prediction of breeding values in order to improve the radiological status of today's riding horses.