Humus und Klimaänderung - Ergebnisse aus 15 langjährigen Dauerfeldversuchen     

Martin Körschens  Erhard Albert  Michael Baumecker  Frank Ellmer  Michael Grunert  Sandor Hoffmann 《Archives of Agronomy and Soil Science》2013,59(11):1485-1517

Zusammenfassung

Die Quantifizierung des Einflusses von Klimaänderungen auf den Humusgehalt des Bodens ist von großer wirtschaftlicher und wissenschaftlicher Bedeutung. Eine Möglichkeit dieser Quantifizierung besteht in der Auswertung von Dauerfeldversuchen mit der kontinuierlichen Bestimmung des Kohlenstoff- und Stickstoffgehaltes von Böden über einen Zeitraum von mehreren Jahrzehnten unter Wahrung des Ceteris-Paribus-Prinzips. Für die vorliegende Arbeit wurden die Ergebnisse von insgesamt 15 Dauerfeldversuchen an zehn verschiedenen Standorten mit rund 150 unterschiedlichen Düngungsvarianten ausgewertet. Die Versuchsdauer lag mit einer Ausnahme zwischen 40 und 110 Jahren. Die C_org-Daten konnten nahezu lückenlos über einen Zeitraum von jeweils 20 Jahren einbezogen werden. Die N_t-Gehalte wurden in sechs Versuchen berücksichtigt. Die Ergebnisse zeigen, dass bei allen Prüfgliedern mit kombinierter organisch-mineralischer Düngung in der Größenordnung, wie sie der “guten fachlichen Praxis“ oder auch der Humusbilanzmethode entspricht, keine Verringerung der C_org-Gehalte eingetreten ist. In einigen Fällen waren signifikante Erhöhungen zu verzeichnen. In 11 von 15 Versuchen war auch ohne Düngung oder mit ausschließlicher Mineraldüngung keine Reduzierung und somit keine klimabedingte Verringerung der Humusgehalte im Untersuchungszeitraum nachweisbar. Stattdessen wurde in einigen Fällen eine signifikante Erhöhung gefunden. Auch bei den N_t-Gehalten war in keinem Fall eine signifikante Verringerung festzustellen. Umfangreiche Großzahlanalysen und Dauerfeldversuchsauswertungen anderer Autoren bestätigen uneingeschränkt die Ergebnisse.  相似文献   

Effect of cattle faeces with different microbial biomass content on soil properties, gaseous emissions and plant growth     

Daphne Isabel Jost  Rainer Georg Joergensen  Albert Sundrum 《Biology and Fertility of Soils》2013,49(1):61-70

A study was carried out to investigate the effects of different diets for heifers, low- and high-yielding cows on the microbial composition of their faeces and subsequently the impacts of these faeces on CO₂ and N₂O emissions, N mineralisation and plant N uptake. A diet low in N and high in acid detergent fibre offered to heifers resulted in faeces dominated by fungi. These faeces were characterised by a low content in microbial biomass C and N and a high ergosterol concentration in comparison to the faeces of high-yielding cows. Added to soil, faeces of heifers led to lower emission and stronger N immobilisation during a 14-day incubation in comparison to the faeces of high-yielding cows. Total N₂O emission was significantly (P?<?0.05) correlated with faecal microbial biomass N. Rye grass yield and N uptake were lowest in the soil supplemented with faeces from heifers in a 62-day pot experiment. Plant N uptake was influenced by the faecal microbial biomass C/N ratio and the fungal C to bacterial C ratio. In conclusion, the faecal microbial biomass was affected to a high degree by the feeding regime and faecal microbial characteristics revealed higher impacts on plant N uptake than soil microbial properties.  相似文献   

Access of Rural Women to Agricultural Information in the Eleme Area of Rivers State,Nigeria     

F. E. Nlerum  C. O. Albert  E. S. Prince-Kaye 《Journal Of Agricultural & Food Information》2013,14(2):192-197

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Chemical characterization of an aqueous extract and the essential oil of Tithonia diversifolia and their biocontrol activity against seed-borne pathogens of rice     

Dongmo  Albert Nanfack  Nguefack  Julienne  Dongmo  Joseph Blaise Lekagne  Fouelefack  François Romain  Azah  Rene Udom  Nkengfack  Ephrem Augustin  Stefani  Emilio 《植物病害和植物保护杂志》2021,128(3):703-713

Journal of Plant Diseases and Protection - The high cost of chemical pesticides and their negative impact on the environment prompted the search for natural pesticides from plants. The objective of...  相似文献   

Short internode,double podding and early flowering effects on maturity and other agronomic characters in chickpea     

Yadeta Anbessa  Tom WarkentinRosalind Bueckert  Albert Vandenberg 《Field Crops Research》2007

Chickpea is an indeterminate species, which continues to flower and set new pods over a long period under wet and cool growing conditions, resulting in excessive canopy development and delayed maturity. We hypothesized that the chickpea's long season requirement could be reduced through introgression of short internode, double podding and early flowering. Four populations E100Ym/CDC Anna, 272-2/CDC Anna, 298T-9/CDC Anna, and 298T-9/CDC Frontier were developed to test this hypothesis with the first parents of each cross being the donor of the short internode, double podding and early flowering traits, respectively. Also, the donor parents E100Ym, 272-2 and 298T-9 were intercrossed. Segregating populations of F₂ to F_3:6 generations were then evaluated under greenhouse and field conditions. When expressed well, double podding significantly reduced time to maturity as compared to the single podding counterparts. The best double podding lines were about 1 week earlier maturing than the early parent and standard checks. Days to flowering (DF) was positively associated with days to maturity (DM) (r = 0.44, P < 0.001), and partial path analysis revealed that DF contributed to DM mainly via days to first pod maturity (DFPM). In the two early flowering populations 298T-9/CDC Anna and 298T-9/CDC Frontier, DF determined about 32% of the variation in DFPM. Conversely, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. In conclusion, the alleles for double podding and early flowering may be used to improve early maturity in chickpea and subsequently minimize the risks associated with the production of this crop in environments where the growing conditions allow excessive crop canopy development, as in the Canadian prairies.  相似文献   

Effect of the new pyrazole carboxamide fungicide penthiopyrad on late leaf spot and stem rot of peanut     

Culbreath AK  Brenneman TB  Kemerait RC  Hammes GG 《Pest management science》2009,65(1):66-73

BACKGROUND: Management of early leaf spot (Cercospora arachidicola Hori.), late leaf spot [Cercosporidium personatum (Berk. & MA Curtis) Deighton] and stem rot (Sclerotium rolfsii Sacc.) of peanut (Arachis hypogaea L.) in the southeastern USA is heavily dependent upon sterol biosynthesis inhibitor (SBI) and quinone outside inhibitor (QoI) fungicides. Effective new fungicides with different modes of action could improve overall disease control and extend the utility of the current fungicides. Penthiopryad is a pyrazole carboxamide fungicide being evaluated for use on peanut. Field experiments were conducted from 2004 to 2007 to determine the effect of a range of rates (0–0.36 kg AI ha^?1) of penthiopyrad on leaf spot and stem rot and the relative efficacy of penthiopyrad and current fungicide standards chlorothalonil, tebuconazole and azoxystrobin. RESULTS: Leaf spot control in plots treated with penthiopyrad at 0.20 kg AI ha^?1 or higher was similar to or better than that for the chlorothalonil standard. The incidence of stem rot for all penthiopyrad treatments was usually less than that for the tebuconazole or azoxystrobin standard treatments. Pod yields for all penthiopyrad treatments were similar to or higher than those for the respective standards. CONCLUSION: Penthiopyrad has excellent potential for management of late leaf spot and stem rot of peanut, and may complement current SBI and QoI fungicides. Copyright © 2008 Society of Chemical Industry  相似文献   

Antifeedant activity of fruit and seed extracts ofMelia azedarach andazadirachta indica on larvae ofSesamia nonagrioides     

Andreu Juan  Albert Sans  Magí Riba 《Phytoparasitica》2000,28(4):311-319

Methanolic extracts of seeds and fruits of the chinaberry tree,Melia azedarach L. (Meliaceae), showed strong antifeedant activity against 2nd instar larvae ofSesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae), a very serious pest of maize(Zea mays L.) in Mediterranean countries. Extracts were applied in an artificial diet at concentrations of 1000 and 2000 ppm. The parameters used to evaluate the activity were larval growth rates; quantity of food ingested; phagodepression/phagostimulation index; quantity of frass produced; quantity of material ingested; duration of larval development; and cumulative mortality. Seed extract showed high bioactivity at both doses, while fruit extract proved to be less active, and only at the higher dose used (2000 ppm) did it display a slight antifeedant activity. The activity of theM. azedarach seed extract at the higher dose (2000 ppm) was comparable to that of pure azadirachtin applied at a dose of 1.25 ppm, or to ‘Mubel’, a commercial extract ofAzadirachta indica A. Juss. (Meliaceae), applied at a dose of 75 ppm.  相似文献   

MAGNETIC RESONANCE IMAGING OF THE NORMAL AND DISEASED FELINE MIDDLE EAR     

Ingrid  Allgoewer  DVM  Susanne  Lucas  DVM  Stephan Albert  Schmitz  MD 《Veterinary radiology & ultrasound》2000,41(5):413-418

The magnetic resonance imaging appearance of the feline middle ear is described in three healthy cats and in five cats with middle ear disease. Owing to the good spatial resolution, multiplanar slice orientation as well as display high contrast resolution of soft tissue, in particular fluids, MR imaging was helpful prior to surgery. It is superior to radiography which failed to allow identification of the abnormality in two of our five cats. MR imaging for middle ear disease should include dorsal and transverse plane images using T1- and T2-weighted sequences. In the presence of a mass within the bulla or the external ear canal application of contrast medium is helpful.  相似文献   

Mit neuen Verfahren gegen Fruchtwickler in Kleingartenanlagen     

Von R. Albert  R. Wolff 《Journal of pest science》2000,73(3):79-82

The availability of pesticides in private gardens is limited by local law in the State of Baden-Württemberg in south-west Germany. Only 26 insecticides, fungicides and molluscicides are permitted. Hence, only pesticides such as Bacillus thuringiensis, Granulosis Virus, pyrethrum or the pheromone mating disruption method (PMDM) can be used for moth control in apple. The use of beneficials like Trichogramma sp. or Chrysoperla carnea is not limited. PMDM had not been previ-ously investigated in allotments until the experiments reported here were carried out in 1998 and 1999. In these experiments, PMDM was compared with the use of the egg parasites, Trichogramma dendrolimi and T. cacoeciae. The observations were done in 102 allotments, each of about 300 m². The gardeners are members of a special club for the allotments and they often organize the bulk acquisition of plants or fertilizers for the club. Sometimes the club obtains plant protection products when something has to be done in all allotments. The codling moth and the plum fruit moth are important pests in these allotments.In 1997, attacks of codling moth were generally low throughout the southern Germany. This was reflected in the allotments where there was less than one per cent fruit damage with PMDM or the egg parasites the following year. During 1999, the attacks were generally much higher resulting in a higher use of insecticides in commercial German orchards. In the allotments, about six to eight per cent of fruits were damaged by the codling moth in both experimental treatments.The results indicate that PMDM can be successful in allotments and is equally as effective as the use of egg-parasites. But further experiments are required.  相似文献   

An on-site computer system for comprehensive agricultural air quality research   总被引：1，自引：0，他引：1  

Ji-Qin Ni  Albert J. Heber 《Computers and Electronics in Agriculture》2010,71(1):38-49

Scientific studies using direct agricultural air quality (AAQ) measurement have experienced revolutionary changes since such a study was first reported in the early 1950s. Comprehensive AAQ research with multi-institutional or international collaboration, long-term monitoring, and multi-pollutant measurement has been conducted with greater frequency. On-site computer system (OSCS), consisting of data acquisition hardware, a personal computer, and custom-developed AAQ research software has become an important tool in these studies. The role of the OSCS has been expanded from exclusively data acquisition to a combination of data acquisition, control, regular and advanced data processing, and communication. This paper studied the general and specific requirements of OSCS in AAQ research and introduced a system with new methodology and technology for high level quality assurance and quality control (QAQC).Data acquisition in AAQ studies is needed for five main categories of instruments and sensors: pollutant concentrations, air exchange, weather conditions, building status, and measurement system status. Regular data processing consists of converting electrical signals to engineering units, averaging data over a given period of time, and performing data correction. Advanced data processing includes calculating location-shared analyzers and sensors (LSAS) data and instrument calibration data and generating daily reports in real-time or upon user requests. The primary control needs in AAQ research centers around the LSAS using multi-point air sampling system. Controls for sampling tubing heating and equipment cooling are often required. Computer communications to monitor system status, deliver alarms and data, and provide remote diagnosis and controls help to reduce operation costs and increase research quality and data completeness.An OSCS that offered flexibility, high capacity, user-friendliness, and high level QAQC was developed for field and laboratory AAQ research. A total of 29 OSCSs have been built and used in various AAQ studies in 13 states in USA for handling a total of more than 3.0 billion data points. The system adapted a set of data processing algorithms as well as some novel features, including All-data Display and Dynamic Run-time Configuration (DDRC), Digital Output DDRC, real-time sampling system monitoring and protection, Global Channel, traceable configuration, and post-measurement data processing. The system also integrated two stand-alone instruments, an Innova multi-gas analyzer and a 7-port Environics gas diluter, which are popular in AAQ research. The strengths, weaknesses, and future development of the system are also discussed.  相似文献