Soil heterogeneity at the field scale: a challenge for precision crop protection     

Stefan Patzold  Franz Michael Mertens  Ludger Bornemann  Britta Koleczek  Jonas Franke  Hannes Feilhauer  Gerhard Welp 《Precision Agriculture》2008,9(6):367-390

Crop protection seldom takes into account soil heterogeneity at the field scale. Yet, variable site characteristics affect the incidence of pests as well as the efficacy and fate of pesticides in soil. This article reviews crucial starting points for incorporating soil information into precision crop protection (PCP). At present, the lack of adequate field maps is a major drawback. Conventional soil analyses are too expensive to capture soil heterogeneity at the field scale with the required spatial resolution. Therefore, we discuss alternative procedures exemplified by our own results concerning (i) minimally and non-invasive sensor techniques for the estimation of soil properties, (ii) the evidence of soil heterogeneity with respect to PCP, and (iii) current possibilities for incorporation of high resolution soil information into crop protection decisions. Soil organic carbon (SOC) and soil texture are extremely interesting for PCP. Their determination with minimally invasive techniques requires the sampling of soils, because the sensors must be used in the laboratory. However, this technique delivers precise information at low cost. We accurately determined SOC in the near-infrared. In the mid-infrared, texture and lime content were also exactly quantified. Non-invasive sensors require less effort. The airborne HyMap sensor was suitable for the detection of variability in SOC at high resolution, thus promising further progress regarding SOC data acquisition from bare soil. The apparent electrical conductivity as measured by an EM38 sensor was shown to be a suitable proxy for soil texture and layering. A survey of arable fields near Bonn (Germany) revealed widespread within-field heterogeneity of texture-related ECa, SOC and other characteristics. Maps of herbicide sorption and application rate were derived from sensor data, showing that optimal herbicide dosage is strongly governed by soil variability. A phytoassay with isoproturon confirmed the reliability of spatially varied herbicide application rates. Mapping areas with an enhanced leaching risk within fields allows them to be kept free of pesticides with related regulatory restrictions. We conclude that the use of information on soil heterogeneity within the concept of PCP is beneficial, both economically and ecologically.  相似文献   

Early pathogen detection under different water status and the assessment of spray application in vineyards through the use of thermal imagery   总被引：3，自引：0，他引：3  

Manfred Stoll  Hans R. Schultz  Gerhard Baecker  Beate Berkelmann-Loehnertz 《Precision Agriculture》2008,9(6):407-417

Remote detection using thermal imagery has potential for use in the pre-symptomatic diagnosis of abiotic stress or of early disease detection. The latter is an issue of great importance since late detection of fungus attacks or poor spray coverage are major factors contributing to weak disease control affecting fruit quality or reducing yield in grapes. In greenhouse experiments the effects on spatial and temporal variability of leaf temperature of grapevine (Vitis vinifera L. cv. Riesling) leaves inoculated with a fungal pathogen (Plasmopara viticola (Berk. & Curt. Ex de Bary) were studied in either well-irrigated or non-irrigated potted plants. Due to the high sensitivity of leaf temperature to the amount of water transpired, infra-red thermography can be used to monitor irregularities in temperature at an early stage of pathogen development. Evidence for characteristic thermal responses in grapevines was apparent well before visible symptoms appeared. Contrasting thermal effects due to the pathogen attack were found between measurements on well-irrigated and water-stressed plants. Furthermore, from a technical point of view, thermal imagery has the potential to assess the evenness of spray coverage within a canopy, hence optimizing pesticide application efficiency.  相似文献   

Breeding for organic agriculture: the example of winter wheat in Austria   总被引：2，自引：2，他引：0  

Franziska Löschenberger  Andreas Fleck  Heinrich Grausgruber  Herbert Hetzendorfer  Gerhard Hof  Julia Lafferty  Marion Marn  Anton Neumayer  Georg Pfaffinger  Johann Birschitzky 《Euphytica》2008,163(3):469-480

Breeding for organic agriculture (BFOA) is a strategy for a commercial breeding company based on the exploitation of the frequently observed high correlation for many traits between conventional, low input (LI) and organic agriculture (ORG). Indirect selection under LI can be useful to roughly divide the germplasm into the genotypes better adapted to high input and those better adapted to LI or ORG conditions. BFOA is an evolving process, in which two methods are currently applied: early generations are either selected following the pedigree system under LI, or grown as bulk populations on ORG fields. In the latter case the system switches to LI after individual ear selection under ORG conditions. In both methods, the first replicated yield trial is grown parallel under ORG and LI. Subsequently, the genotypes are grouped into conventional or ORG advanced trial series. The BFOA strategy allows that the larger genetic variability of both the organic and conventional gene pool can be exploited in the selection for ORG. Hitherto, seven winter wheat varieties were released in Austria after exclusive organic VCU testing.  相似文献   

Man and technology in irrigated agriculture: DVWK Bulletin, 8. P. Parey,Hamburg/Berlin,Federal Republic of Germany. xiv + 245 pp., 15 figs., 15 tables,DM 39.00. ISBN 3-490-00890-1     

Gerhard W. Schiefer 《Agricultural Water Management》1984,9(3):265-266

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A Novel Approach to Brachycephalic Syndrome. 2. Laser‐Assisted Turbinectomy (LATE)          下载免费PDF全文

Gerhard U. Oechtering  Sabine Pohl  Claudia Schlueter  Riccarda Schuenemann 《Veterinary surgery : VS》2016,45(2):173-181

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Evaluation of a high‐sensitivity cardiac troponin I assay compared to a first‐generation cardiac troponin I assay in Doberman Pinschers with and without dilated cardiomyopathy     

Lena Klüser  Elizabeth T. Maier  Gerhard Wess 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2019,33(1):54-63

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Effects of drought‐stressed temperate forage legumes on the degradation and the rumen microbial community in vitro     

Susanne Riede  Carola Lindig  Hansjrg Abel  Bettina Tonn  Johannes Isselstein  Gerhard Breves 《Journal of animal physiology and animal nutrition》2019,103(2):436-446

According to climate change scenarios, central Europe may expect extending drought periods during summer. Lower water availability may influence the ruminal digestion of individual forage legume species differently. To test this hypothesis, Lotus corniculatus L. (var. Bull), Medicago lupulina L. (var. Ekola), Medicago falcata L. (wild seeds) and Trifolium repens L. (var. Rivendel) were each grown in parallel lots of control and drought‐stressed monocultures. Rainout shelters (installed in May 2011 on a regrowth after first cut until harvest in mid of June) withheld rainfall of 40 mm in the drought stress treatment. Samples of dried (60°C) and milled (5 mm screen) forage legumes were incubated in a simulation experiment using Rusitec to assess drought effects on parameters for microbial metabolism. Degradability of dry matter and organic matter as well as methane production decreased in incubations with drought‐stressed compared to control variants of legume species. Degradability of crude protein, neutral detergent fibre, acid detergent fibre and residual organic matter including non‐fibre carbohydrates and lipids were affected by interactions between drought stress and species. Significant interactions were also found for ammonia concentrations, molar SCFA proportions and the microbial communities. It is concluded that drought stress for growing forage legumes influences their ruminal degradation and fermentation as well as the ruminal microbial communities of Bacteria and Archaea differently in a legume species‐dependent manner.  相似文献   

Effect of dietary iodine on growth and iodine status of growing fattening bulls     

Ulrich Meyer  Kristin Weigel  Friedrich Schne  Matthias Leiterer  Gerhard Flachowsky 《Livestock Science》2008,115(2-3):219-225

The aim of the present study was to assess the influence of different levels of iodine supplementation on animal growth and the iodine content of food from beef cattle. In a dose–response experiment with 34 growing fattening bulls of the “German Holstein” breed, in the range from 223 to 550 kg body weight, three iodine dosages were tested. The animals were fed a corn silage/concentrate ration. Iodine concentration in the diet amounted to 0.79 (Group 1), 3.52 (Group 2) and 8.31(Group 3) mg I per kg dry matter (DM). After slaughtering, I was determined in blood, serum, plasma, thyroid, liver, kidneys and meat (M. longissimus dorsi, M. glutaeus medius) by ICP-MS. I-supplementation did not significantly influence DM intake, daily weight gain (1453 (1), 1419 (2) and 1343 (3) g; p > 0.05) or slaughtering performance, but the weight of the thyroid gland increased significantly with the highest I dosage (32 (1), 26 (2) and 42 (3) g animal^− 1, p < 0.05). I-supplementation significantly increased I-concentration in muscle, liver, kidney and thyroid gland (p < 0.05). The contribution of beef food to I-intake of humans is relatively low, therefore there is no need to reduce the EU-upper limit (10 mg kg^− 1 feed) for growing fattening cattle from the view of consumer safety. In view of animal health and performance more dose–response studies seem to be necessary.  相似文献   

Interpretation of lysimeter weighing data affected by wind     

Reinhard Nolz  Gerhard Kammerer  Peter Cepuder 《植物养料与土壤学杂志》2013,176(2):200-208

Weighing lysimeters are valuable devices for measuring water‐balance components with high temporal resolution and high accuracy. However, some older lysimeter facilities still operate with lever‐arm‐counterbalance weighing systems that are sensitive to disturbances, e.g., forces exerted by wind. Filtering and averaging are commonly used for processing noisy raw data. We studied some data of a lever‐arm weighing system and performed additional experiments in order to (1) determine the measurement accuracy of the current weighing scheme (facility, and measuring and averaging procedure) regarding wind effects, (2) describe the oscillation behavior, (3) test the mechanical performance of the system, and (4) adapt the averaging procedure with respect to improved interpretation of the weighing data. The measurement accuracy for a wind velocity < 5 m s^–1, measured in 10 m height, was ≈ ± 0.4 kg (equivalent to ± 0.14 mm); at a higher wind velocity, the accuracy was three times lower, but there was no linear relationship. Additional experiments showed that the weighing system is oscillating with more or less irregular amplitudes. A loading–unloading experiment delivered proper results of the measured loads. The mechanical system reacted immediately, and no directional effects were found. However, small changes of < 1 kg could hardly be determined due to the oscillations. A time series of raw data measured every 2 s served as basis for improving the averaging method. A moving average from 64 values was computed representing the currently used method, and serving as reference. With this procedure an accuracy of ± 0.38 kg could be reached. Averaging 150 values led to an accuracy of ± 0.28 kg (0.1 mm) for a wind velocity < 5 m s^–1.  相似文献   

Ergebnisse eines 10jährigen statischen Stickstofformen-und Stickstoffsteigerungsversuches     

Gerhard Fiedler  Edgar Linke  Eberhard Streuber 《Archives of Agronomy and Soil Science》2013,59(8-9):649-673

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