栽培措施对双低油菜苏油4号产量和品质的影响   总被引：7，自引：0，他引：7  

孙华  沈明星  蒋鹤云  许才康  张建栋 《上海农业学报》2008,24(4)

种植密度、施肥水平、肥料运筹等栽培措施对苏油4号产量和品质影响的研究结果表明:(1)移栽密度7 500株/667 m2、施纯氮22 kg/667 m2和基、腊、苔花肥配比4∶2∶4是苏油4号获得高产的适宜栽培措施,其产量达到207.33 kg/667 m2。(2)影响产量的主导因子是施肥水平,其次是种植密度和肥料运筹。(3)随密度和施氮量增加,单位面积有效角果数呈增多趋势,但在低密度条件下,受肥料运筹影响;千粒重随密度的增加而减少,随施氮量的增加而增加,肥料运筹对千粒重的影响不显著。施肥水平对每角粒数起正向作用。(4)苏油4号高产栽培的主攻重点是单位面积有效角果数。(5)随着施氮量的增加,含油率、蛋白质含量降低;就肥料运筹而言,随着基、腊肥的增加,苔花肥的减少,含油率、蛋白质含量增加。  相似文献   

铁和维生素A及互作对肉仔鸡生产性能和钙磷表观存留率的影响   总被引：2，自引：0，他引：2  

贾春燕 《西北农业学报》2008,17(3):68-72

选用504只一日龄艾维因肉仔鸡为研究对象,采用完全随机试验设计,随机分成9组,每组4个重复,试验分成0~4周龄和5~7周龄两个阶段。日粮中维生素A有3个添加水平,分别是750、1500、2700I U/kg,铁的添加水平为0、30、60 mg/kg,。结果表明,常规日粮中添加铁对内仔鸡的生产性能影响不显著(P>0.05),添加vA对前后期体增重及日采食量影响均不显著(P>0.05),但对料重比影响接近显著(P≈0.05),Fe和vA交互作用对体增重影响显著(P<0.05)。铁添加水平对钙磷表观存留率影响均不显著(P>0.05),维生素A在前期显著影响钙磷表观存留率(P<0.05),后期仅二者的互作效应对钙磷表观存留率影响显著(P<0.05)。  相似文献   

桃叶卫矛假种皮浸提液对种子发芽的影响   总被引：2，自引：0，他引：2  

李华英  张勇哲  罗广军 《延边大学农学学报》2008,30(1):58-62

用桃叶卫矛假种皮的浸提液对萝卜种子进行处理(2种溶剂,3个浓度梯度,即浸提液原液的10%,5%,2.5%)的结果表明,水浸提液处理的发芽率均为60%~70%;浓度为10%的乙醇浸提液处理的种子发芽率很低,甚至不发芽;浓度为2.5%的乙醇浸提液处理的种子发芽率也在40%以下;而乙醇处理的种子发芽率都在80%以上.因此,桃叶卫矛的假种皮浸提液对种子发芽有抑制作用.  相似文献   

Experimental Study on, Small Span to Depth Ratio Coupling Beams withNew Reinforcement mewt Scheme and Design Method     

FU Jian ping  CHENG Jing zhou  Pi Tian xiang  BAI Shao liang 《保鲜与加工》2008,(2):37-42

Coupling beams combining two coupled walls are the primarily energy dissipating elements in the coupled walls and play a key role in improving ductility. It is proved by the test outcome at home and abroad that the shear failure happening early cannot be  相似文献   

不同水热处理对刨花板苯酚液化效果的影响     

朱本城  赵广杰 《林产工业》2008,35(4)

对实验室自制刨花板和回收废弃刨花板分别进行水热处理,在两种不同的液化条件下对处理的刨花板粉进行液化,利用液化残渣率为指标,分析不同水热条件处理对刨花板苯酚液化的影响。在不同的液化条件下得出相同的结果:同一水热处理时间下,两种刨花板的液化残渣率都随着温度的升高而呈现降低的趋势;同一水热处理温度下,液化残渣率也随着处理时间的增加而呈现降低的趋势,水热处理温度比水热处理时间对刨花板苯酚液化的影响效果大。对实验结果进行数据分析得到较理想的最佳水热处理条件是:实验室自制刨花板水热温度80℃,水热处理时间6h;回收废弃刨花板水热温度80℃,水热处理时间8h。  相似文献   

Effects of nitrogen fertilizer rates and ratios of base and topdressing on wheat yield, soil nitrate content and nitrogen balance   总被引：1，自引：0，他引：1  

Yu Shi  Zhenwen Yu 《Frontiers of Agriculture in China》2008,2(2):181-189

Application of nitrogen (N) fertilizer is one of the most important measures that increases grain yield and improves grain quality in winter wheat (Triticum aestivum L.) production. Presently, there is a large number of investigations (experiments) in the field on different nitrogen fertilizer application regimes. However, there still exists a serious problem of low nitrogen use efficiency, especially in winter wheat high yield conditions: unsuitable nitrogen fertilizer, which often leads to lower yield and large accumulation of nitrate in the soil, bringing a potential risk to the environment. In order to explore the optimal regime of nitrogen fertilizer application suitable for environment and economy, a field experiment on the different rate and ratio of base and topdressing of nitrogen fertilizer at the different growth periods of winter wheat was conducted. The field experiment was undertaken from the fall of 2003 to the summer of 2004 in the village of Zhongcun in Longkou city, in the Shandong Province of China. The field experiment with three repeats for each treatment was designed in a split-plot. The major plot was applied with urea at a nitrogen fertilizer rate of three levels, namely, 0 kg·hm⁻² (CK), 168 kg·hm⁻² (A), and 240 kg·hm⁻² (B). In the sub-plot, the ratios of base and topdressing nitrogen fertilizer at the different development periods of wheat were 1/2:1/2 (A1 and B1), 1/3:2/3 (A2 and B2) and 0:1 (A3 and B3). Treatment B1 was under a regime used now in the local region. It was found that the amount of N accumulation in plants had no significant difference between treatments applied with nitrogen fertilizer. The grain yield and grain protein content were all elevated remarkably by applying nitrogen fertilizer compared with those of treatment CK. There was no significant difference in the grain yield and grain protein content between A2 and B2 and B3. However, when compared with those of B2 and B3, in A2 there was an increase in nitrogen use efficiency and residual soil NO₃ ⁻-N and N losses were reduced. Under the condition of the same rate of nitrogen fertilizer, increasing topdressing nitrogen rate clearly elevated the grain yield, grain protein content and nitrogen use efficiency. The results indicated that the residual soil NO₃ ⁻-N in A1 and B1 accumulated higher than that of CK in 80–160 cm soil layers at the jointing stage, but that of A2 had no significant difference compared with that of CK in 0–200 cm soil layers. At the maturity stage, more residual soil NO₃ ⁻-N was detected in B2, B3 and A3 than that in CK in 120–180 cm soil layers, which could not be absorbed by the roots of wheat, but led to be eluviated easily. The amount of soil NO₃ ⁻-N accumulation in treatment A2 had no significant difference compared with that of treatment CK in the 100–200 cm soil layer. In conclusion, A2, whose nitrogen fertilizer rate was 168 kg·hm⁻² and the ratio of base and topdressing was 1/3:2/3, had a higher grain yield and grain protein content, and heightened N use efficiency and minimized the risk of NO₃ ⁻-N leaching. This should be one of the most appropriate nitrogen fertilizer application regimes in wheat production in local regions in China. __________ Translated from Acta Ecologica Sinica, 2006, 26(11): 3661–3669 [译自: 生态学报]  相似文献   

Estimating N status of winter wheat using a handheld spectrometer in the North China Plain   总被引：1，自引：0，他引：1  

Fei Li  Martin L. Gnyp  Liangliang Jia  Yuxin Miao  Zihui Yu  Wolfgang Koppe  Georg Bareth  Xinping Chen  Fusuo Zhang 《Field Crops Research》2008

Excessive nitrogen (N) fertilizer application is very common in the North China Plain. Diagnosis of in-season N status in crops is critical for precision N management in this area. Remote sensing, as a timely and nondestructive tool, could be an alternative to traditional plant testing for diagnosing crop N status. The objectives of this study were to determine which vegetation indices could be used to estimate N status in winter wheat (Triticum aestivum L.) under high N input conditions, develop models to predict winter wheat N uptake using spectral vegetation indices and validate the models with data from farmers’ fields. An N rate experiment and a variety-N experiment were conducted in Huimin, Shandong Province from 2005/2006 to 2006/2007 to develop the models. Positive linear relationships between simple ratio vegetation indices (red vegetation index, RVI and green vegetation index, GVI) and N uptake were observed independent of growth stages and varieties (R², 0.48–0.74). In contrast, the relationships between normalized difference vegetation indices (NDVI and GNDVI), red and green normalized difference vegetation index (RGNDI), and red and green ratio vegetation index (RGVI) were exponentially related to N uptake (R², 0.43–0.79). Subsequently, 69 farmers’ fields in four different villages were selected as datasets to validate the developed models. The results indicated that the prediction using RVI had the highest coefficient of determination (R², 0.60), the lowest root mean square error (RMSE, 39.7 kg N ha⁻¹) and relative error (RE, 30.5%) across different years, varieties and growth stages. We conclude that RVI can be used to estimate nitrogen status for winter wheat in over-fertilized farmers’ fields before heading.  相似文献   

性比对非繁殖期圈养白鹇行为的影响     

肖绍军  张眷兰  钟象景  刘丙万 《安徽农业科学》2008,36(22)

[目的]为了探讨性比对个体行为的影响。[方法]2007年9~11月在广东象头山国家级自然保护区采用随机取样法和瞬时扫描取样法开展了3种性比圈养白鹇的行为学研究。[结果]不同性比的白鹇都具有明显的日节律:取食高峰出现在16:00~17:00,休息高峰在12:00~13:00。在时间分配上,同一性比的雄性与雌性间存在差异:性比为2∶2时,雄性与雌性在游走和休息上的差异极显著(P<0.01);性比为3∶1时,雄性与雌性在取食和游走的差异极显著(P<0.01)。不同性比的同性间仍存在差异∶雄性在性比为2∶2与3∶1时游走的差异极显著(P<0.01);雌性在性比为2∶2与3∶1时取食和游走的差异极显著(P<0.01),并在性比为3∶1与3∶0时取食和游走的差异极显著(P<0.01)。不同性比的白鹇个体之间亲疏关系不同,但总有2只雌性个体关系密切。[结论]性比对白鹇圈养白鹇的行为时间分配有影响,而且雌性个体更趋于集群活动,雄性则趋于单个活动。  相似文献   

徐州城区空间形态变化的研究     

闫志刚  田海川 《安徽农业科学》2008,36(22)

依据Boyce-Clark形状指数、紧凑度指数,测度徐州近30年来的城区形状变化,确定各阶段的形状类型,分析了形状变化与城市发展模式的关系。  相似文献   

Establishment,survivorship, and growth of yellow birch seedlings after site preparation treatments in large gaps     

François Lorenzetti  Sylvain Delagrange  Daniel Bouffard  Philippe Nolet 《Forest Ecology and Management》2008

The occurrence of yellow birch (YB) in the northeastern forests of North America is a source of concern. Several guidelines suggest ways to favor the regeneration of this species, including creating openings from small gaps to large clearcuts, coupled or not with a variety of soil preparation treatments. However, it is not clear if soil preparation treatment favors YB establishment by simply increasing the availability of good seedbed types, or by also altering competition pressure exerted by interfering species during the period of seedling establishment. For this study, large gaps (900 m²) were created in a 70-year old YB dominated forest, to which three treatments differing in soil disturbance intensities were applied (i.e., soil scarification (i) using a rake [raking]; or (ii) by dragging slash out to the edges of the gap [slash drag]; and (iii) limited to the passage of the harvesting equipment [control]). The proportion of seedbed types reportedly most favorable for YB establishment (i.e., mineral-dominated) increased as the severity of the site preparation increased. The opposite was observed for organic-dominated seedbeds. As a result, the stocking of YB seedlings increased with the severity of site preparation. However, YB stocking was deemed sufficient in all gaps to ensure future canopy dominance, even in the control treatment. Although YB seedlings generally achieved greater heights as site preparation intensity increased, it was clear that this did not reflect vigorous growth as, on average, greater heights coincided with greater seedling height–diameter ratios. At the seedbed level, height–diameter ratio was associated with an increase in surrounding competition pressure and an increase in the incidence of stem apical death (SAD), which in turn decreased height differences among seedbed types by the end of the study. At the gap level, this blurred the advantages of site preparation over a laisser-faire strategy. The incidence of SAD was greatest in the slash drag and the rake treatments. Consequently, we cannot say that intense soil scarification is worth the expenses, especially in stands where YB seed sources are abundant.  相似文献