Influence of stage of development in the efficiency of nitrogen fertilization on poplar     

Berta Lasa  Ivan Jauregui  Iker Aranjuelo  Sandra Sakalauskiene  Pedro M. Aparicio-Tejo 《Journal of plant nutrition》2016,39(1):87-98

Poplar cuttings (Populus x euroamericana) were planted in pots and grown in a greenhouse for four months with drip irrigation. Two nitrogen (N) doses of 60 and 120 kg nitrate (N-NO₃^?) ha^?1 (labeling with ¹⁵N stable isotopes) were applied at one (time I), two (time II) and three months after of the plantation (time III). The aim of this study was to determine the N-fertilizer application method that resulted in optimal N-uptake by a short-rotation of poplar crop during first year of growth. Our data revealed that NUE (N use efficiency) was largest in the last part of the experiment. The larger development of those plants at this stage enabled the improved absorption and assimilation of N. Furthermore, ¹⁵N also revealed that supply of N at three months post-planting generated more biomass and increased the N reserves in the stem; a key factor for ensuring the optimum regrowth during the second year.  相似文献   

竹原纤维和竹粉纤维形态和化学成分分析     

温晓芸  郑蓉  郑维鹏 《世界竹藤通讯》2015,13(5):12

以3年生毛竹材为原料,研究了毛竹竹粉和竹原纤维的纤维形态和化学成分。纤维形态分析结果表明:竹原纤维的宽度(143μm)与竹粉(136μm)相当,长度(22.63 mm)远高于竹粉(0.61 mm),使其长宽比(158.25)远高于竹粉(4.49)。化学成分分析表明:竹原纤维的纤维素含量(65.6%)比竹粉(37.3%)高得多,聚戊糖含量(17.1%)略低于竹粉(20.1%)。竹粉中的木质素含量为24.5%,是竹原纤维中木质素含量(11.5%)的2倍多。竹原纤维的高纤维素含量和低木质素含量是其广泛应用于制浆造纸行业的重要原因。  相似文献   

籼粳杂交稻枝梗和颖花形成的播期效应   总被引：3，自引：0，他引：3  

曾研华  张玉屏  王亚梁  向镜  陈惠哲  朱德峰 《中国农业科学》2015,48(7):1300-1310

【目的】探讨播期对不同籼粳杂交稻穗粒数形成规律的影响。【方法】以杂交稻偏粳型中熟中粳甬优8号、偏籼型迟熟中粳甬优15号、中熟晚籼钱优2号和常规品种迟熟中粳浙粳88为材料,通过分期播种研究不同类型水稻枝梗和颖花分化与退化的特性及其与籼粳性成分的关系。【结果】籼粳杂交稻甬优8号及甬优15号每穗总颖花分化数均显著高于籼稻钱优2号和粳稻浙粳88;甬优品种的一次枝梗及颖花分化数显著高于籼、粳稻,二次枝梗和颖花分化数以偏籼型品种甬优15号和钱优2号较高,而甬优8号二次颖花分化数与钱优2号的基本持平。随播期推迟,每穗总颖花分化数显著降低,尤为二次颖花分化数,而一次颖花分化数以适期播种最高。甬优8号和钱优2号总颖花分化数以早播显著高于适期播种和迟期播种,甬优15号则以适期播种最高,适期播种能显著提高籼粳杂交稻品种甬优8号和甬优15号的一次颖花现存数,主要体现在稻穗中上部与穗基部、顶部,这与其较高的一次枝梗分化能力有关。不同播期间,各类型品种稻穗不同部位一次枝梗上的二次枝梗分化数从穗基部到穗顶部总体呈下降趋势,而二次枝梗和颖花现存数、二次颖花分化数总体呈现“先升后降”的趋势。其中甬优8号不同部位一次枝梗上二次枝梗和颖花现存数的早播优势主要体现在穗中上部位,钱优2号早播的优势为稻穗中下部,甬优15号适期播种的优势主要体现在穗顶部,而浙粳88迟播的影响主要体现在稻穗基部。相关分析表明,各类型品种粳性成分与稻穗总颖花分化数及一次、二次枝梗和颖花分化数均呈极显著抛物线关系,相关系数分别为0.8172、0.9416、0.9004、0.8718和0.7988。【结论】与籼、粳稻相比,籼粳杂交稻具有较多的枝梗数和颖花数。推迟播期,降低每穗颖花分化数和二次枝梗分化数;早播有利于中熟品种颖花和二次枝梗的形成,而适期播种对迟熟品种的效应较好。不同播期下各类型品种粳性成分与稻穗枝梗和颖花呈极显著相关。  相似文献   

欧李的营养成分测定与分析   总被引：7，自引：1，他引：6       下载免费PDF全文

李晓亮 《农学学报》2015,5(8):97-100

欧李是一种野生矮小灌木树,属蔷薇科樱桃属欧李树种。我们将可食的果实部分的营养成分进行了分析测定,并与苹果作了比较,结果表明：欧李果实含有丰富的糖、蛋白质、微量元素、维生素C、17种氨基酸等多种营养物质,其中微量元素与部分必需氨基酸含量高于苹果,尤其是钙和铁的含量甚高,是一种理想的天然补钙保健果品。  相似文献   

Seasonal dynamics of bioenergy characteristics in grassland functional groups          下载免费PDF全文

I. Melts  K. Heinsoo 《Grass and Forage Science》2015,70(4):571-581

Semi‐natural grasslands (SNG) are considered as bioenergy resources, either for combustion or for biogas production. To provide information on the seasonal (June–August) dynamics of herbage quantity and chemical composition, we studied the effects of factors on the proportions of four plant functional groups, chemical composition and total biomass yield at twelve sites representing three Estonian SNG types. Biomass yield increased only in alluvial meadows with the largest contribution of sedges/rushes (39%). Grasses dominated in dry‐to‐mesic meadows (62%) and other forbs in wooded meadows (55%). Concentration of fibre was highest in grasses and sedges/rushes (682 and 645 g NDF kg^?1), and lignin was highest in legumes and other forbs (103 and 113 g kg^?1). Legumes contained more C and N (447 and 25 g kg^?1) and grasses more Cl (1 g kg^?1). The highest concentrations of Mg, K and ash were in other forbs (4, 18 and 80 g kg^?1), and Ca in legumes (16 g kg^?1). The results are discussed in the context of suitability of different functional groups and SNG types for bioenergy conversion. Grasses and sedge‐/rush‐rich biomass are considered suitable for methane production. Biomass harvesting in July and minimizing the problems with N and Cl during combustion need to be considered. Forb‐rich biomass should be pre‐treated before direct combustion.  相似文献   

Suitability of tef varieties in mixed wheat flour bread matrices: A physico-chemical and nutritional approach     

《Journal of Cereal Science》2015

Wheat flour replacement from 0 to 40% by single tef flours from three Ethiopian varieties DZ-01-99 (brown grain tef), DZ-Cr-37 (white grain tef) and DZ-Cr-387 (Quncho, white grain tef) yielded a technologically viable ciabatta type composite bread with acceptable sensory properties and enhanced nutritional value, as compared to 100% refined wheat flour. Incorporation of tef flour from 30% to 40% imparted discreet negative effects in terms of decreased loaf volume and crumb resilience, and increase of crumb hardness in brown tef blended breads. Increment of crumb hardness on aging was in general much lower in tef blended breads compared to wheat bread counterparts, revealing slower firming kinetics, especially for brown tef blended breads. Blended breads with 40% white tef exhibited similar extent and variable rate of retrogradation kinetics along storage, while brown tef-blended breads retrograded slower but in higher extent than control wheat flour breads. Breads that contains 40% tef grain flour were found to contain five folds (DZ-01-99, DZ-Cr-387) to 10 folds (DZ-Cr-37) Fe, three folds Mn, twice Cu, Zn and Mg, and 1.5 times Ca, K, and P contents as compared to the contents found in 100% refined wheat grain flour breads. In addition, suitable dietary trends for lower rapidly digestible starch and starch digestion rate index were met from tef grain flour fortified breads.  相似文献   

Nutritional components and antioxidant properties of seven kinds of cereals fermented by the basidiomycete Agaricus blazei     

《Journal of Cereal Science》2015

The aim of this work was to evaluate the effects of solid-state fermentation (SSF) by basidiomycete Agaricus blazei Murrill (ABM) on the nutritional components and antioxidant properties of wheat, rice, oat, corn, millet, broomcorn millet and sorghum.The results showed that the contents of nutritional components in the fermented cereals varied with the fermentation time. After SSF of ABM, the enhancement rates of millet in total phenols, amino acid nitrogen and water-soluble protein content were the highest, which were respectively 4.03, 12.04 and 10.37 times higher than that of the control; the enhancement rates of wheat in total protein and reducing sugar content were the highest, which were 0.32 and 100.77 times higher than that of control. According to 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power, ferrous ion chelating ability and superoxide anion radical scavenging ability of ethanolic extracts from the fermented cereals, it was shown that the antioxidant properties of the cereals were significantly stronger than that of control after fermented by ABM. The improvement degrees of sorghum in DPPH radical scavenging capacity and superoxide anion radical scavenging ability were the highest, the improvement degrees of wheat in reducing power and ferrous ion chelating ability were the highest.  相似文献   

紫花苜蓿和裸燕麦混贮发酵品质和营养成分分析   总被引：3，自引：0，他引：3  

葛剑  杨翠军  杨志敏  白雪梅  赵海香  刘贵河 《草业学报》2015,24(4):104-113

以新鲜及晾晒后的紫花苜蓿和裸燕麦为原料,分别设计紫花苜蓿单贮、裸燕麦单贮、裸燕麦∶紫花苜蓿=1∶1、裸燕麦∶紫花苜蓿=2∶1及裸燕麦∶紫花苜蓿=1∶2混贮等5个处理,青贮60 d后,对其感官评分、发酵品质和营养成分等进行分析。结果表明,鲜贮苜蓿在感官评定、V-Score及Kaiser评价体系中表现一般,而晾晒及混合青贮各处理组均能不同程度提高青贮评分。晾晒和混合青贮对发酵品质产生影响,两者显著或极显著降低pH值、 PA(丙酸)、AA(乙酸)、BA(丁酸)和AN/TN(氨态氮/总氮)含量(P＜0.01或P＜0.05),显著或极显著升高LA(乳酸)含量(P＜0.01或P＜0.05),其中以裸燕麦∶紫花苜蓿=2∶1降低或升高最明显。晾晒对青贮饲料的干物质、可溶性碳水化合物及粗灰分含量具有显著或极显著影响(P＜0.05或P＜0.01),对其他养分含量影响不大(P>0.05)。混合比例对青贮饲料的所有发酵项目均有极显著影响(P＜0.01),对粗蛋白质、可溶性碳水化合物及中性洗涤纤维含量具有显著或极显著影响(P＜0.05或P＜0.01),对其他养分指标影响不显著(P>0.05)。晾晒和混合青贮的交互作用可显著提高青贮饲料的发酵品质,但对养分含量影响不明显。因此,从青贮后感官评价、发酵品质及养分含量来看,紫花苜蓿和裸燕麦混合青贮品质优于单独青贮,且晾晒相对于鲜贮更易于青贮,而无论晾晒和鲜贮,当裸燕麦∶紫花苜蓿=2∶1时,青贮品质均优于其他各组。  相似文献   

蜥蜴对内蒙古典型草原群落多样性和地上生物量的影响     

杨涵越  聂梅  黄永梅  张景慧 《草地学报》2015,23(2):246-251

为研究蜥蜴(Phrynocephalus frontalis)活动对内蒙古典型草原群落多样性、地上生物量、群落结构、生活型组成以及优势种生物量的影响,于2012年6月和8月在内蒙古毛登牧场围封草场内布设有蜥蜴样地和对照样地,进行样方调查和生物量取样.结果表明:与对照样地相比,蜥蜴样地6月的Shannon-Wiener指数和均匀度显著降低,8月Shannon-Wiener指数、均匀度和物种丰富度均显著低于对照样地;蜥蜴样地的群落生物量在6月和8月分别比对照样地高68.85和111 g·m^-2;在功能群水平,蜥蜴样地一年生植物和多年生禾草的生物量比例比对照样地增加了19.1%和11.0%,而多年生杂类草生物量比例降低了19.8%;在物种水平,蜥蜴样地羊草(Leymus chinensis)生物量的比例在生长季节初期达到了75.0%.可见在内蒙古典型草原,蜥蜴干扰可使一年生植物和多年生禾草的生物量比例增加,而使多年生杂类草的物种数和生物量比例显著降低;蜥蜴干扰显著促进了羊草的生长;同时会降低群落的物种多样性,提高地上生物量.  相似文献   

添加黑麦草饲粮对鹅肉脂肪酸组成的影响     

冯德庆  黄勤楼  黄秀声  陈钟佃  钟珍梅 《草地学报》2015,23(6):1323-1328

本研究旨在观察饲粮中添加不同比例多花黑麦草(Lolium multiflorum Lam)对鹅肉脂肪酸组成影响,揭示牧草摄食量与鹅肉α-亚麻酸(ALA)相对含量之间的关系。选用50羽14日龄长乐灰鹅,分成5个处理,饲养期60 d。各处理饲粮中黑麦草干物质比例分别为: 0.00%(CK),5.42%,11.92%,19.52%和27.24%。结果表明:随着饲粮中黑麦草比例的提高,鹅肉ALA相对含量显著增加,试验各组分别比对照组增加了86.90%,197.24%(P<0.05),393.10%(P<0.05)和304.83%(P<0.05);PUFA/SFA显著上升(P<0.05);n-6PUFA/n-3PUFA显著下降(P<0.05)。鹅肉ALA相对含量与饲粮中黑麦草比例的曲线回归模型方程为:y=0.270+0.106x-0.002x²(F=22.99^**)。当饲粮中黑麦草的干物质比例在0%～26.50%时,鹅肉ALA的含量呈上升趋势;当黑麦草的比例超过26.50%时,鹅肉ALA的含量转而呈下降趋势。说明黑麦草中的ALA能够通过摄食消化过程沉积到鹅肉中。  相似文献