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De renaissance van het gemengde bedrijf.
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An exponential decline was fitted to measured losses of organic nitrogen from grass soils during the 25 years after ploughing. The experiments were carried out on soils of the Romney and Blacktoft series from the Holland district of Lincolnshire. The fitted line estimated that half of the decline took place in the first 5.5 years and 90% in 18 years. Almost 4 t N ha−1 from soil organic matter were lost from the top 0–25 cm of soil.Losses calculated from the fitted equation were then imposed upon known rates of ploughing of grass throughout England and Wales so that the potential contribution of ploughed grass to nitrate leaching during the last 50 years could be estimated. By the end of the Second World War, ploughed grass could have increased the concentration of nitrate in draining water by more than 40 mg NO3-N 1−1 in parts of Lincolnshire, the Midlands and East Anglia. In 1972, after another period of increased ploughing, there was a further increase of 15 mg N 1−1. Water draining from a field of ploughed grass could contain up to 450 mg N 1−1 in the first season after ploughing.A calculation was made of the area of land that may safely be ploughed out of pasture each year if the EC limit of 11.3 mg N 1−1 is not to be exceeded in water draining from each of the countries of England and Wales. In parts of the Midlands and East Anglia, the nitrate from ploughed grass (representing less than 0.1% of the land area) could currently be responsible for more than half of the loading towards the EC limit.
De renaissance van het gemengde bedrijf: een weg naar duurzaamheid
- E A Lantinga
- H H Van Laar
Lantinga, E.A., en H.H. van Laar, Eds.
(1997), "De renaissance van het gemengde
bedrijf: een weg naar duurzaamheid", Bedrijfs-en onderzoeksplan van twee gemengde bedrijven op de lr A.P. Minderhoudhoeve.
- W J Weijden
- H Van Der
- H J Van Der Wal
- N A De Graaf
- W Van Brussel En
Weijden, W.J. van der, H. van der Wal, H.J.
de Graaf, N.A. van Brussel en W.J. ter Keurs
(1984), Bouwstenen voor een geTntegreerde
landbouw. Voorstudies en achtergronden
V44 (Wetenschappelijke Raad voor het Regeringsbeleid, Den Haag), 196 pp.
Duurzame risico's: een blijvend gegeven. Rapporten aan de Regering nr
WRR (1994), Duurzame risico's: een blijvend gegeven. Rapporten aan de Regering
nr. 44 (Wetenschappelijke Raad voor het
Regeringsbeleid, Den Haag), 208 pp.
Oomen en professor dr
- Ir E A Dr
- Ir G J M Lantinga
Dr.ir. E.A. Lantinga, ir. G.J.M. Oomen
en professor dr.ir. R. Rabbinge zijn verbonden aan het Departement Plant-en
Gewaswetenschappen van de Landbouwuniversiteit Wageningen.
Nitrogen efficiency of grassland-based dairy farming-New perspectives using an integrated approach
- J Bruchem
- M W Van
- S J Bosch En
- Costing
Bruchem, J. van, M.W. Bosch en S.J. Costing (1996); "Nitrogen efficiency of grassland-based dairy farming-New perspectives using an integrated approach", in: A.F.
Groen en J. van Bruchem (eds.), Utilization
of local feed resources in dairy cattle (Wageningen Press}, pp. 99-101.