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| Petersen, J.; Eskesen, K.. |
| Udbringningsmetoden for gylle påvirker konkurrencen mellem afgrøde og ukrudt om tilført kvælstof. Ved bredspredning af gødningen kan ukrudtet optage en betydelig del af den tilførte gødning, og dermed bliver ukrudtet en konkurrent til afgrøden. Forholdet i ukrudt/afgrøde konkurrencen om den tilførte gødning kan forskydes til afgrødens fordel ved direkte nedfældning af gødningen. I dette års forsøg undersøges hvilken betydning afstanden mellem kornrækken og gødningsstrengen har for konkurrence mellem afgrøde og ukrudt om tilført kvælstof. Der er udvalgt en vårsæds-mark med en høj naturlig ukrudtsbestand. Den lille parcelstørrelse (30?40 cm) skyldes, at den tilførte gylle er tilsat isotopmærket kvælstof. Herved er det muligt at beregne, hvor stor en andel... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Composting and manuring Weed management Cereals; Pulses and oilseeds. |
| Ano: 2002 |
URL: http://orgprints.org/282/1/poster_c1.ppt |
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| Schmitt, A.; Elliot, M.; Thirumalai, K.; La, C.; Bassinot, F.; Petersen, J.; Movellan, A.; Jorry, Stephan; Borgomano, J.. |
| The ratio of magnesium to calcium (Mg/Ca) in foraminiferal shells is commonly used as a proxy for past ocean temperature. Recent advances in elemental analyses now enable single-specimen measurements of planktic foraminifera and thus, can provide information on past seasonal and interannual variability, owing to the near-monthly lifespan of foraminifera. In this study, we explore the temperature variance recorded by Mg/Ca in tests of foraminifera Globigerinoides ruber, a planktic species that occurs throughout the year in tropical waters. Using LA-ICP-MS, we characterize Mg/Ca variability in single specimens of two morphotypes of G. ruber picked from a sediment core retrieved offshore New Caledonia. We provide an estimate of the range of calcification... |
| Tipo: Text |
Palavras-chave: Globigerinoides ruber; Mg/Ca ratio; Sea surface temperature; LA-ICPMS; Seasonality; Quaternary. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58336/60890.pdf |
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| Petersen, J.. |
| The experiments were carried out in the two spring barley fields of the organic six-course cattle:crop rotation at Foulumgaard,Denmark. The weed density was 300 and 1800 plants m-2 respectively. Pig slurry was applied by hand in microplots by four methods:broadcasting followed by incorporation,or injected in bands to depths of 5,10 or 15 cm. Spring barley and weeds were sampled separately six times during the tillering and elongation phase of the spring barley. The effect of application method on dry-matter (d.m.)production, nitrogen uptake and recovery of applied nitrogen in the spring barley and the weeds is reported. Slurry banding halved the weed d.m. and weed N uptake compared with broadcasting,irrespective of weed density. Weeds recovered up to 12%of... |
| Tipo: Journal paper |
Palavras-chave: Composting and manuring Weed management Cereals; Pulses and oilseeds. |
| Ano: 2003 |
URL: http://orgprints.org/280/2/The_paper_is_available_at_the_library.doc |
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