A Comparison of the Leachable Inorganic Nitrogen Content in Organic and Conventional Farming Systems
Kristensen, S. P.; Mathiasen, J.; Lassen, J.; Madsen, H. B.; Reenberg, A.; Kristensen, S. P.; Institute of Geography, University of Copenhagen; Mathiasen, J.; Institute of Geography, University of Copenhagen; Lassen, J.; Institute of Geography, University of Copenhagen; Madsen, H. B.; Institute of Geography, University of Copenhagen; Reenberg, A.; Institute of Geography, University of Copenhagen
Журнал:
Acta Agriculturae Scandinavica, Section B – Soil & Plant Science
Дата:
1994
Аннотация:
AbstractSoil samples collected from 26 organic and 550 conventional farms during autumn 1990 through the national Grid Net Survey (GNS) and a simultaneous supplementary survey on 8 organic farms have been analyzed in order to estimate the risk of nitrogen leaching. The average nitrate N (nitrogen) content in the soil (0–75 cm) was very similar in samples from organic farms (31kg/ha) and conventional farms using manure (29 kg/ha), but superior to that of conventional farms not using manure (22 kg/ha). Samples collected from fields on organic farms cultivated with grass with clover or alfalfa were very small (12 kg/ha) compared to samples from fields cultivated with cereals (57 kg/ha) and samples from bare fields following cereals (48 kg/ha). The average nitrate N content was higher in samples from clayey soil (40 kg/ha) than from sandy soils (15 kg/ha). The nitrate N content in samples from regions with a high percolation level during the autumn (August to December 1990) was lower than in samples from regions with a low percolation level.
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