Andreas Pacholski
University of Kiel
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Featured researches published by Andreas Pacholski.
Soil Research | 2002
R. E. White; Guixin Cai; Deli Chen; Xiaohui Fan; Andreas Pacholski; Zhaoliang Zhu; Hong Ding
Gaseous nitrogen losses, by NH3 volatilisation and denitrification, are mainly responsible for the low recovery of N fertiliser applied to irrigated maize on the North China Plain. Two field experiments were conducted to measure NH3 volatilisation and nitrification-denitrification losses from urea applied to maize (Zea mays L.) grown on a calcareous fluvo-aquic soil (Aquic Inceptisol) in Fengqiu County, Henan Province. The first was carried out in June 1998 (urea applied at 75 kg N/ha 3 weeks after sowing), and the second in July 1998 (urea applied at 200 kg N/ha 6 weeks after sowing). Each experiment included 3 treatments-control, surface-broadcast (SB), and deep point placement (DP) or broadcast followed by irrigation (BI). NH3 loss was measured by a micrometeorological method (NH3 sampler). Denitrification (N2 + N2O) was measured by the acetylene inhibition-intact soil core technique, and N2O emission was also measured in the absence of acetylene. The recovery of applied N was measured by a 15N balance technique. When urea was surface broadcast (SB) 3weeks (75 kg N/ha) and 6weeks (200 kg N/ha) after sowing, 44 and 48% of the applied N was lost by NH3 volatilisation, respectively. The corresponding losses from the BI and DP treatments were only 18% and 11%, respectively. Denitrification was a significant process in this well-drained sandy soil, with average loss rates of 0.26-0.43 kg N/ha.day in the controls (from resident soil N), compared with 0.52-0.63 kg N/ha.day in the surface fertiliser treatments. Deep placement of urea reduced the denitrification rate to an average of 0.3 kg N/ha.day. The net denitrification loss from the fertiliser was <2% of the applied N, except for the SB urea treatment in the second experiment. The application of N fertiliser as urea increased N2O emissions from c. 0.3 to c. 2.3 kg N/ha over 57 days in the second experiment, with average N2O emission rates in the control and SB treatment of 0.006 and 0.042 kg N/ha.day, respectively. The significantly lower ratio of N2 /N2O in the urea treatments compared with the control suggested that nitrification of applied N may have contributed to N2O production. Alternatively, the ratio of N2 /N2O during denitrification may have changed with the greater supply of NO3 -. denitrification, maize, NH3 volatilisation, N2O emission.
Nutrient Cycling in Agroecosystems | 2006
Andreas Pacholski; Guixin Cai; Rolf Nieder; Jörg Richter; Xiaohui Fan; Zhaoliang Zhu; Marco Roelcke
The determination of ammonia volatilization with sufficient spatial and temporal resolution requires a simple and versatile in situ measurement technique, particularly in developing countries. Therefore, a simple chamber method for determining ammonia (NH3) volatilization in the field (Dräger-Tube Method; DTM) was calibrated by comparison with simultaneous measurements with a micrometeorological Integrated Horizontal Flux (IHF) method. Five field experiments were conducted following urea fertilization on summer maize and winter wheat plots (1998–1999) at Fengqiu Experimental Station, Central China. The simplicity of the chamber method allowed for measurements to be carried out by trained farmers. The measurements with both methods yielded very similar patterns of NH3 fluxes and similar differences between fertilization treatments. Cumulative NH3 losses determined by the IHF method ranged from 14.6 to 47.9% and from 0.6 to 17.9% of urea-N applied for surface broadcast and incorporated fertilization, respectively. As expected, cumulated NH3 losses were underestimated by the DTM as compared to the IHF by about one order of magnitude. A calibration equation was calculated by multiple linear regression which included NH3 flux data as well as temperature and wind speed values. The calibration model yielded a modelling efficiency c2 of 0.86 resulting in an average estimation error of cumulative NH3 losses of 17%. The equation was validated by comparison of IHF measurements and DTM fluxes not considered in the derivation of the calibration formula. The calibration approach can be used under similar meteorological and field conditions irrespective of the soil characteristics or type of N fertilizer applied.
Agriculture, Ecosystems & Environment | 2010
Martin Erbs; Remy Manderscheid; Gisela Jansen; Sylvia Seddig; Andreas Pacholski; Hans-Joachim Weigel
European Journal of Agronomy | 2015
Chris Kollas; Kurt Christian Kersebaum; Claas Nendel; Kiril Manevski; Christoph Müller; Taru Palosuo; Cecilia M. Armas-Herrera; Nicolas Beaudoin; Marco Bindi; Monia Charfeddine; Tobias Conradt; Julie Constantin; Josef Eitzinger; Frank Ewert; Roberto Ferrise; Thomas Gaiser; Iñaki García de Cortázar-Atauri; Luisa Giglio; Petr Hlavinka; Holger Hoffmann; Munir P. Hoffmann; Marie Launay; Remy Manderscheid; Bruno Mary; Wilfried Mirschel; Marco Moriondo; Jørgen E. Olesen; Isik Öztürk; Andreas Pacholski; Dominique Ripoche-Wachter
Agriculture, Ecosystems & Environment | 2012
R. Quakernack; Andreas Pacholski; A. Techow; Antje Herrmann; F. Taube; Henning Kage
European Journal of Agronomy | 2010
Remy Manderscheid; Andreas Pacholski; Hans-Joachim Weigel
Biosystems Engineering | 2011
Dirk O. Gericke; Andreas Pacholski; Henning Kage
Field Crops Research | 2009
Remy Manderscheid; Andreas Pacholski; Cathleen Frühauf; Hans-Joachim Weigel
Agriculture, Ecosystems & Environment | 2014
Kang Ni; Andreas Pacholski; Henning Kage
Journal of Plant Nutrition and Soil Science | 2008
Andreas Pacholski; Guixin Cai; Xiaohui Fan; Hong Ding; Deli Chen; Rolf Nieder; Marco Roelcke