枯落物分解与土壤蓄水能力关系的研究     

贲越  周一杨  李彧  陈祥伟 《安徽农业科学》2007,35(5):1416-1416,1418

枯落物层分解产生的有机质不仅是森林重要的营养来源,而且对改变土壤理化性质,提高土壤蓄水量都有积极影响.通过分析枯落物层的分解对土壤结构等特性的改变来论述这一观点.  相似文献   

Silicon suppresses a ubiquitous mite herbivore and promotes natural enemy attraction by altering plant volatile blends     

Islam  Tarikul  Moore  Ben D.  Johnson  Scott N. 《Journal of pest science》2022,95(1):423-434

Journal of Pest Science - Silicon (Si) accumulation in plants is widely recognised as an effective physical defence against chewing herbivores. However, its effects on some feeding guilds such as...  相似文献   

Recalibrating plant water status of winter wheat based on nitrogen nutrition index using thermal images     

Zhao  Ben  Adama  Traore  Ata-Ul-Karim  Syed Tahir  Guo  Yan  Liu  Zhandong  Xiao  Junfu  Liu  Zugui  Qin  Anzhen  Ning  Dongfeng  Duan  Aiwang 《Precision Agriculture》2022,23(3):748-767

Precision Agriculture - Accurate and timely assessment of crop water status is imperative for in-season irrigation scheduling in crop production. The canopy water stress index and water deficit...  相似文献   

污泥-凹凸棒石共热解生物炭对矿区重金属污染土壤的钝化修复效果研究     

陶玲  马奔  李中兴  周怡蕾  任珺 《农业环境科学学报》2022,41(6):1251-1260

通过钝化实验研究了在污泥中添加不同质量比（0、5%、10%、15%、20%、25%、30%）的凹凸棒石后制备的污泥-凹凸棒石共热解生物炭对矿区污染土壤中重金属的控制效应。结果表明：在矿区重金属污染土壤中添加污泥-凹凸棒石共热解生物炭后,土壤pH值随凹凸棒石添加量的增加而呈增加趋势,土壤电导率和阳离子交换量也整体呈现出上升的状态。加入污泥-凹凸棒石共热解生物炭钝化处理后,矿区污染土壤中Cu、Cd、Ni、Zn、Cr的TCLP提取态重金属含量均呈现下降趋势,钝化效率分别为94.71%、95.60%、91.75%、99.03%、96.65%;除Cu的DTPA提取态含量增加了5.93%~24.97%外,Cd、Ni、Zn、Cr的DTPA提取态含量也均有所降低,钝化效率分别为94.32%、94.75%、86.63%、90.02%、92.54%。酸溶态的Cd、Cu、Ni、Zn、Cr也向更加稳定的残渣态转化,其修复效率分别为42.50%、33.87%、57.92%、33.74%、42.36%,重金属的4种形态之和与重金属总量具有良好的一致性,一致率为82%~105%。根据土壤管控标准风险等级,重金属污染土壤钝化处理后,Cd、Cu、Ni、Zn、Cr均保持在低风险水平。Cd、Cu、Ni和Zn的潜在风险指数降低,虽然Cr的潜在风险指数有所升高,但是在所有处理条件下Cr的污染等级均为轻度。研究表明,在污泥中添加凹凸棒石增强了污泥生物炭对重金属的钝化性能。  相似文献   

Chemometric Multivariate Analyses of Kernel Biometric Techniques and Shell Morphological Attributes for Analyzing Pistacia vera L. Genotypes Variability     

Ennouri  Karim  Smaoui  Slim  Ben Hlima  Hajer  Ben Ayed  Rayda  Ben Braiek  Olfa  Mellouli  Lotfi  Triki  Mohamed Ali 《Erwerbs-Obstbau》2022,64(2):283-290

In this study, the corresponding correlations, interdependencies, and relationships of nine traits of pistachio (Pistacia vera L.) kernels were established. Here, the percentage of dehiscent shells, shell homogeneity, shell apex, position of suture opening, suture opening, number of pistachio kernels/100?g, (length/width) pistachio kernel ratio, pistachio kernel flavour and fat content of pistachio kernel were studied.

The evaluation of experimental data was performed by applying a chemometric approach: Principal Component Analysis (PCA), Bayesian Networks method and Network Meta-Analysis. In this regard, based on PCA the first principal component of shell and kernel had high loadings for shell homogeneity. By using Bayesian Networks method, dendrogram of selected pistachio varieties demonstrate a high similitude existing between varieties. Furthermore, the of shell and kernel dendrogram of studied pistachio varieties demonstrated that all studied accessions could be separated into four distinct groups. Based on cluster analysis, a detailed comparison between the varieties demonstrated that the accession named ‘KERMAN’ showed a significant similarity with the Tunisian genotype ‘ELGUETAR’. In this line, Network Meta-Analysis exhibited the different interdependencies between morphological parameters, and the hierarchical clustering via heat maps displayed relationships between studied factors.

These results showed a potential use of desired characteristics at least in some infra-specific studies in Pistacia vera L. The findings of this study will help plant growers by highlighting hidden and eventual relationships between Pistacia vera L. varieties.

  相似文献   

Purification of a Low Molecular Weight Fucoidan for SPECT Molecular Imaging of Myocardial Infarction     

Pierre Saboural  Frédéric Chaubet  Francois Rouzet  Faisal Al-Shoukr  Rana Ben Azzouna  Nadia Bouchemal  Luc Picton  Liliane Louedec  Murielle Maire  Lydia Rolland  Guy Potier  Dominique Le Guludec  Didier Letourneur  Cédric Chauvierre 《Marine drugs》2014,12(9):4851-4867

Fucoidans constitute a large family of sulfated polysaccharides with several biochemical properties. A commercial fucoidan from brown algae, containing low molecular weight polysaccharidic species constituted of l-fucose, uronic acids and sulfate groups, was simply treated here with calcium acetate solution. This treatment led to a purified fraction with a yield of 45%. The physicochemical characterizations of the purified fucoidan using colorimetric assay, MALLS, dRI, FT-IR, NMR, exhibited molecular weight distributions and chemical profiles similar for both fucoidans whereas the sulfate and l-fucose contents increased by 16% and 71%, respectively. The biodistribution study in rat of both compounds labeled with ^99mTc evidenced a predominant renal elimination of the purified fucoidan, but the crude fucoidan was mainly retained in liver and spleen. In rat myocardial ischemia-reperfusion, we then demonstrated the better efficiency of the purified fucoidan. This purified sulfated polysaccharide appears promising for the development of molecular imaging in acute coronary syndrome.  相似文献   

择伐对阔叶红松林细根生物量及其时空分布的影响   总被引：2，自引：1，他引：1       下载免费PDF全文

张犇  金光泽 《林业科学研究》2014,27(2):240-245

以择伐40年后的阔叶红松林过伐林(以下简称为择伐林)和未砍伐的典型阔叶红松林(以下为原始林)为研究对象,探讨了择伐对细根生物量时空分布的影响。结果表明生长季原始林和择伐林死细根生物量、活细根生物量和总细根年平均生物量没有显著差异(P0.05);总细根生物量以及活细根在6月以及9月存在显著差异(P0.05),死细根在5月、7月以及8月存在显著差异(P0.05);原始林和择伐林的细根生物量随土层深度的增加逐渐减少,80%的活细根和75%以上的死细根分布在0 20 cm的土层中,其总细根生物量、活根和死根仅在3040 cm存在显著差异(P0.05);原始林和择伐林的不同直径级(2 5 mm和≤2 mm)的活细根的生物量比、死细根的生物量比以及总细根生物量比在相同土层内没有显著差异(P0.05)。  相似文献   

鲩、鲢鱼种摄食强度变化的一些规律          下载免费PDF全文

张本 《水产学报》1966,3(1):41-51

我国各地培育鱼种的方法多种多样,近年来从投饵和施肥为中心的有关鱼种培育方法和营养生物学的研究已引起了养鱼工作者的普遍重视。要想获得体质健壮,成活率也很高的鱼种,就是要加强培育管理,在饵料基础方面做到精细投饵和合理施肥。饵料和肥料的效能与投饵和施肥技术有密切的关系,投饵和施肥的技术措施是根据鱼种摄食强度等因子而制订的。鱼种的摄食强度直接受到它们本身生长发育特点和外界环境条件所抑制,有着一定的变化规律。鱼种摄食强度的变化有哪些规律,影响摄食强度的主要因素是什么?这些问题的阐明,将在鱼种营养生态、生理学的理论与投饵和施肥技能的生产实践上都具有重要的意义。  相似文献   

Reproductive response of fat‐tailed Barbarine ewes subjected to short‐term nutritional treatments including spineless cactus (Opuntia ficus‐indica f. inermis) cladodes     

C. Sakly  M. Rekik  I. Ben Salem  N. Lassoued  A. Gonzalez‐Bulnes  H. Ben Salem 《Journal of animal physiology and animal nutrition》2014,98(1):43-49

Reproductive outputs in fat‐tailed Barbarine sheep in central Tunisia are often low because of feed shortage and the low nutritive value of diets. Supplementation with conventional concentrates is economically unsuitable in central Tunisia, so more cost‐effective and sustainable alternative feeding strategies need to be developed. We tested effects of short‐term nutritional treatments including cactus cladodes during the induction of ‘male effect’ on fertility and prolificacy parameters (follicular growth, ovulatory response and early embryo losses). One hundred and twenty ewes were distributed in 4 equal groups balanced for live weight grazed natural pastures and were supplemented for 21 days, starting day 10 after introduction of rams, with cactus cladodes (CA), cactus cladodes and soybean meal (CAS), concentrate (CC) or only soybean meal (S). Nutritional treatment did not affect live weight in this experiment. Ewes receiving cactus had higher number of large pre‐ovulatory follicles (≥6 mm; 1.08 ± 0.05), between days 14 and 19 after introduction of rams, than females in the CC and S ewes (0.64 ± 0.06; p < 0.05). However, there were no differences in the onset of oestrous behaviour in response to ‘male effect’ or in the number of corpora lutea. Average ovulation rates were 1.42 ± 0.16 for CC, 1.47 ± 0.13 for CAS, 1.31 ± 0.15 for CA and 1.31 ± 0.13 for S groups respectively. Finally, reproductive wastages at day 35 after mating were not different between groups being 0.33 ± 0.19 for CC, 0.60 ± 0.17 for CAS, 0.43 ± 0.16 for CA and 0.31 ± 0.15 for S groups respectively. It is concluded that Barbarine ewes fed nutritional treatments including cactus performed similarly to those receiving diets including conventional concentrate feeds.  相似文献   

Efficiency of Oestrous Synchronization by GnRH,Prostaglandins and Socio‐Sexual Cues in the North African Maure Goats     

M Rekik  H Ben Othmane  N Lassoued  C Sakly 《Reproduction in domestic animals》2014,49(3):499-504

This study aims to develop at different seasons, for local North African Maure goats, synchronizing protocols simultaneously to the standard ‘S’ protocol using progestagens in association with prostaglandins and gonadotropin. In late May, 40 goats were assigned to either the ‘S’ protocol or to a protocol where oestrus and ovulation were induced by the buck effect in single‐injection progesterone‐treated goats and provoking early luteolysis using prostaglandin 9 days after exposure to bucks ‘B’. During the 72 h after the treatments ended, 15 and 5 goats expressed oestrus in the ‘S’ and ‘B’ protocols (p < 0.01). Mean time to oestrus was shorter for ‘S’ than for ‘B’ goats. Ovulation rate averaged 2.1 ± 0.22 and 1.60 ± 0.35 for, respectively, ‘S’ and ‘B’ goats (p > 0.05). During mid‐September, 60 goats were assigned to either ‘S’ treatment, ‘PGF’ treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11 days apart or to ‘GnRH’ treatment where the goats had their oestrus and ovulation synchronized with a GnRH (day 0)–prostaglandin (day 6)–GnRH (day 9) sequence. More ‘S’ goats were detected in oestrus over the 96‐h period after the end of the treatments (88.8, 73.7 and 55% in ‘S’, ‘PGF’ and ‘GnRH’ treatments, respectively; p < 0.05). Mean ovulation rates were 2.3 ± 0.27, 1.33 ± 0.27 and 1.33 ± 0.27 for, respectively, ‘S’, ‘PGF’ and ‘GnRH’ goats (p < 0.001). Despite a similar ovulatory response to ‘S’ protocol, efficiency of prostaglandin and GnRH‐based treatments should be tested in mid‐breeding season.  相似文献