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| Thomsen, I. K.; Schjønning, P.; Christensen, B. T.. |
| In order to investigate the effect of soil moisture and texture on C and N mineralization of applied organic matter, sheep faeces was sandwiched between two halves of intact soil cores and incubated at 20°C. The soils contained 10.8 (L1), 22.4 (L3) and 33.7% (L5) clay, respectively, and were drained to seven different matric potentials in the range –15 to –1500 hPa. Evolution of CO2-C was determined during four weeks of incubation. Contents of NO3-N, 15N and microbial biomass N were determined at the end of the incubation. The net release of CO2-C from the faeces (estimated as the difference between soils with and without faeces) and the total CO2-C evolution from soils with faeces was not related to soil moisture contents. Most CO2-C evolved from faeces... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2003 |
URL: http://orgprints.org/271/1/HarmTaskBf%C3%A6ces_rev1.doc |
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| Schjønning, P.; Thomsen, I. K.; Moldrup, P.; Christensen, B. T.. |
| Quantification of in situ soil microbial activity is indispensable in order to improve manipulation of nutrient turnover in soil and optimize crop nutrient supply. We sampled 100 cm3 cores of undisturbed arable soil at three locations along a naturally occurring clay gradient (L1: 11% clay; L3: 22% clay; L5: 34 % clay). The cores were drained to seven different matric potentials in the range –15 to –1500 hPa and gas diffusion determined prior to a 4 week incubation at 20oC in the dark. For all soils the net nitrification increased with water content to a maximum (L1: 12.1, L3: 10.3 and L5: 8.2 g NO3-N g-1 soil) and then decreased with further increase in water content. The water content at maximum nitrification was 0.26, 0.37 and 0.42 m3 m-3,... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2003 |
URL: http://orgprints.org/273/1/MS_S02%2D0112_text.doc |
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| Thomsen, I. K.; Schjønning, P.; Olesen, J.E.; Christensen, B. T.. |
| The turnover of native and applied C and N in undisturbed soil samples of different texture but similar mineralogical composition, origin and cropping history was evaluated at –10 kPa water potential. Cores of structurally intact soil with 108, 224 and 337 g clay kg-1 were horizontially sliced and 15N-labelled sheep faeces was placed between the two halves of the intact core. The cores together with unamended treatments were incubated in the dark at 20°C and the evolution of CO2-C determined continuously for 177 d. Inorganic and microbial biomass N and 15N were determined periodically. Net nitrification was less in soil amended with faeces compared with unamended soil. When adjusted for the NO3-N present in soil before faeces was applied, net nitrification... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2003 |
URL: http://orgprints.org/272/1/HarmTaskArev.doc |
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