Soil organic matter in water-stable aggregates under different soil management practices in a productive vineyard

In a productive vineyard, the influence of different soil management practices on carbon sequestration and its dynamic in water-stable aggregates of Rendzin Leptosol was studied. In 2006, an experiment of different management practices in a productive vineyard was established in the locality of Nitra-Dra?ovce, in the Nitra winegrowing area of Slovakia. The following treatments were established: (1) control (grass without fertilization); (2) T (tillage); (3) T + FM (tillage + farmyard manure); (4) G + NPK3 (grass + NPK 120–55–195 kg ha^?1); and (5) G + NPK1 (grass + NPK 80–35–135 kg ha^?1). The results showed that the lowest soil organic matter content (9.70 g kg^?1) in water-stable microaggregates was determined in G + NPK3, as well as in T. However, the highest soil organic matter content in the highest size fractions of water-stable macroaggregates (>5 mm) was observed in T + FM (19.7 g kg^?1). The highest value for carbon sequestration capacity in water-stable microaggregates was observed in the ploughed farmyard manure treatment. However, the control treatment showed the highest values for carbon sequestration capacity in water-stable macroaggregates, including agronomically favourable size fractions (0.5–3 mm). In all soil management practices under a productive vineyard the most intensive changes in the soil organic matter content were observed in the highest size fractions (>3 mm) of water-stable macroaggregates.     

Total organic carbon and its composition in long-term field experiments in the Czech Republic

Abstract

Total organic carbon content and its composition have been evaluated in the topsoil in the selected plots of 13 long-term field experiments conducted in different soil and climate conditions. The altitude of the sites ranged from 225 – 670 m above sea level. Four variants of the organic and mineral fertilization were selected in each experiment: Nil, which did not receive any organic or mineral fertilizers since the beginning of the experiment, mineral fertilized variant NPK, organic fertilized (manured) variant FYM and both organic and mineral fertilized variant FYM + NPK. Total organic carbon (C) content in the topsoil differed as a result of the soil and climate conditions (it ranged from 0.96 – 1.80% C in the Nil variants) and due to the organic and mineral fertilization. The inert and decomposable part of the soil organic C content was calculated and the hot water soluble carbon content was determined. Relationships between the individual SOM fractions have shown a highly significant correlation, except for the decomposable C calculated as a difference to Nil variant.     

根部吸收氟啶虫酰胺在玉米植株中的分布特点及对玉米蚜虫活性效果评价

采用水培营养液施药的方法,评价氟啶虫酰胺在玉米植株内的时空分布规律和对玉米蚜虫的活性效果。结果表明,根部吸收氟啶虫酰胺后,玉米地上部氟啶虫酰胺积累量于药后4~8d达到最大值,之后缓慢减少;根部氟啶虫酰胺持留量在药后1~2d逐渐增加,2~32d相对稳定;从对玉米蚜虫的活性效果来看,氟啶虫酰胺各浓度药后1d即表现出一定的防治效果,防效在23.33%~38.22%,蚜虫蜜露分泌数极显著低于空白对照,随着处理时间的延长,氟啶虫酰胺对蚜虫防治效果逐渐增高,处理后16d,氟啶虫酰胺31.25和125.00mg/L处理的防效分别达88.60%和99.49%,蜜露抑制率分别达96.70%和99.95%,蚜虫蜜露分泌数随着药液处理浓度的提高而逐渐减少,蚜虫蜜露抑制率高于相同时间和相同浓度下的虫口防治效果。因此,氟啶虫酰胺可通过玉米地下部处理防治蚜虫。     

酸枣幼根原生质体的制备

以生长6~9 d的酸枣种子幼根为试验材料,0.7 mol·L^-1甘露醇作为渗透压稳定剂、pH值5.5~6.0、28℃恒温水浴条件下,以光学显微镜观察的水解总时间、初始产生原生质体的时间、原生质体产量及细胞碎片量为指标,研究通过酶水解来制备酸枣幼根原生质体的方法。结果表明,在含1%果胶酶+4%纤维素酶R-10+3%纤维素酶RS组合的酶解液中,保温4 h可制得产量较高、细胞碎片量较少的原生质体。     

宁夏三北防护林建设成效与问题研究

在分析宁夏三北防护林工程建设现状的基础上,对宁夏三北防护林工程所取得的生态、经济和社会效益作了评价,总结了宁夏三北防护林体系工程建设经验,对于工程建设中存在的问题进行讨论。根据新时期工程建设规划,结合宁夏自身的自然环境与经济状况,为确保宁夏三北工程圆满完成和协调发展,在工程建设、资金管理、行政管理方面提出了的一系列建议与措施。     

Residues of diflubenzuron on horse chestnut (Aesculus hippocastanum) leaves and their efficacy against the horse chestnut leafminer, Cameraria ohridella

Residues of the insect growth regulator diflubenzuron were quantified on horse chestnut (Aesculus hippocastanum L.) leaves treated with a diflubenzuron 480 g litre^?1 SC, Dimilin. To analyse the samples, an analytical procedure was developed involving a simple extraction step followed by high‐performance liquid chromatography on an octadecyl‐modified silica column with methanol + 0.01 M ammonium acetate mobile phase. The results showed diflubenzuron to be highly stable on horse chestnut leaves; more than 4 months (127 days) after application, 38% (on average) of the insecticide still remained on/in the leaves. The data confirmed biological observations showing diflubenzuron's long‐term efficacy against the horse chestnut leafminer, Cameraria ohridella Deschka & Dimi?, which is the most important pest of the horse chestnut in Europe. The hypothesis of possible penetration of diflubenzuron into the leaf mass is explored and discussed. Copyright © 2006 Society of Chemical Industry     

Zusammenfassende Betrachtung der Kenntnisse über die Roßkastanien-miniermotte,Cameraria ohridella Desch. & Dem. (Lep., Gracillariidae)

An overview of knowledge about the horse chestnut minerCameraria abridella Desch. & Dem. (Lep., Gracillariidae), a pest developing in leaf mines ofAesculus bippocastanum, spread gradually from the Ohrid-Lake (Macedonia) through Bosnia, Serbia and Croatia up to the central Europe (fig.). At present (1999) it occurs in northern Italy, Switzerland, Hungary, Czech and Slovak Republics, Austria, southern and central Germany and in southern Poland. Usually three, but up to five generations develop a year in central-European conditions.C. obridella develops also in leaf mines onAcer pseudoplatanus andA. platanoides. The parasitation is 1–8% and seems not to increase. Heavily attacked trees do not die; only rarely the dying of heavily damaged trees have been observed. Several insecticides may be used to control of this pest. The most successful was the growth-regulator Dimilin with active substance of Diflubenzurol. In the future it will be possible to control populations ofCameraria obridella by pheromones. The future development of this pest and its control is discussed.      

Adaptation of native syrphid flies to new exotic plant (Impatiens spp.)-aphidant associations in Central Europe (Dipt., Syrphidae; Hom., Aphididae; Hym., Formicidae)

Impatiens parviflora andI. glandulifera, two invasive touchme-not species of exotic origin were found to be associated with two aphid groups in Central Europe: a) Exotic species subsequently following their invasive plant hosts (Impatientinum asiaticum Nevsky), b) native species secondarily adapted to the new exotic hosts (Aphis fabae cirsiiacanthoidis Scop.). The species number (listed) of associated syrphid flies in the newly developed guilds was rather high, consisting of broadly oligophagous species. The plant phenology and adaptation of the aphids have resulted in associations which apparently represent seasonally significant sources of prey, their importance apparently increasing with the decreasing season. Antattendance was determined in both aphid species, and no adverse interference with the preying syrphid larvae was observed. In spite of an overall classification of the target plants as expansive weeds, they are classified positively as contributing to the enhancement of syrphid fly populations in the biocorridors in the cultivated landscape.     

Correction to: Effect of soil preparation method on root development of P. sylvestris and P. abies saplings in commercial forest stands

New Forests - The article [Effect of soil preparation method on root development of P. sylvestris and P. abies saplings in commercial forest stands], written by [Santa Celma, Katrīna Blate,...