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Soil nitrogen fluxes in Swedish and Nigerian agricultural systems

Röing, Kristina (2005). Soil nitrogen fluxes in Swedish and Nigerian agricultural systems. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2005:57
ISBN 91-576-6956-2
[Doctoral thesis]

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Abstract

The aim of this thesis was to study selected processes of N fluxes in Swedish and Nigerian agricultural systems and relate them to the use of mineral and organic amendments and other agricultural management practices. Long-term effects of crop rotation, crop residue treatment and mineral fertiliser application levels on topsoil carbon (C), plant N uptake, net N mineralisation and soil organic matter fractions in temperate soils were investigated using soils from Swedish long-term agricultural field experiments (16-40 years). Topsoil carbon (C) was measured and plant N uptake was estimated in a pot experiment using soils (0-30 cm) from six locations in Sweden: Fjärdingslöv, Lönnstorp, Lanna, Bjertorp, Högåsa and Röbäcksdalen. Topsoil C content was significantly affected by crop rotation (ley > cereals), although crop residue return had no significant effect. Plant N uptake was up to 50% higher in soils from crop rotations with long-term leys than cereals. Net N mineralisation and microbial respiration was measured in an incubation study using soils from four locations: Lönnstorp, Lanna, Bjertorp, Röbäcksdalen. Net N mineralisation was greater in soils from ley crop rotations. Crop residue return had no effect on net N mineralisation. Soils from two locations (Lönnstorp and Lanna) were size-density fractionated. Preliminary results indicate that an unexpectedly high fraction of soil C and N in the low-input soils was found in fine fractions not associated with minerals. Abundance and mobilisation of non-exchangeable ammonium (NEA) in soils (0-30 cm) from five locations of the long-term experiments in Sweden was estimated. NEA contents in these Swedish soils ranged from 20-200 ppm and increased with clay content. NEA content decreased over 168 days by up to 60% during a pot experiment where ryegrass was grown, suggesting that NEA partly can become plant-available during the cropping season. The potential for in situ produced legume organic matter (OM) was tested in a dry season legume fallow rotation in a field experiment in Ibadan, Nigeria. Five legumes (Pueraria phaseoloides, Vigna unguiculata, Glycine max, Mucuna pruriens and Cajanus cajan) were evaluated in terms of dry season biomass production, effect on following maize crop and fertiliser yield increase. Biomass production ranged from 1000-8300 kg ha-1, which was generally greater than that of the natural fallow. Maize yields, which ranged between 1000-2600 kg ha-1, increased with 10-35% after addition of the in situ produced legume OM. Depending on legume placement (early incorporation, surface application and late incorporation) maize grain yield increased with up to 25 kg for every kg of fertiliser added. N2O fluxes were measured in situ in a legume-maize crop rotation in a field trial in Ibadan, Nigeria, where OM was incorporated prior to maize planting. Fluxes were measured during two rainy seasons and one dry season. Fluxes up to 138 µg m-2 h-1 were observed. Annual N2O-related N losses were estimated to be up to 8 kg N ha-1. The results presented here indicate that farmer management decisions, be it in Sweden or Nigeria, can significantly affect N fluxes, which will in turn affect long-term agricultural and environmental sustainability.

Authors/Creators:Röing, Kristina
Title:Soil nitrogen fluxes in Swedish and Nigerian agricultural systems
Year of publishing :2005
Volume:2005:57
Number of Pages:49
Papers/manuscripts:
NumberReferences
ALLI. Röing, K. Andrén, O. Mattsson, L. 2005. Long-term management effects on plant N uptake and top soil carbon levels in Swedish long-term field experiments – cereals and ley, crop residue treatment and fertiliser N application. Acta Agriculturae Scandinavica, 55(1), 16-22 II. Röing, K. Andrén, O. Mattsson, L. ”Non-exchangeable” ammonium in soils from Swedish long-term agricultural experiments – mobilisation and effects of fertiliser application. (Accepted in Acta Agriculturae Scandinavica) III. Röing, K. Andrén, O, Diels, J. Abaidoo, R. Improved fallows in West African cropping systems – fertiliser yield increase in dry season legume-maize rotations. (Manuscript) IV. Röing, K. Andrén, O. Boeckx, P. Diels, J. Abaidoo, R. N2O fluxes in maize-legume cropping systems in Nigeria – effect of legume residue incorporation and fertiliser application. (Manuscript)
Place of Publication:Uppsala
ISBN for printed version:91-576-6956-2
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:P Natural resources > P35 Soil fertility
Subjects:Not in use, please see Agris categories
Agrovoc terms:nitrogen cycle, ammonia, soil fertility, nutrient availability, fertilizers, croping system, sweden, nigeria
Keywords:long-term field experiments, N mineralisation, non-exchangeable ammonium, tropical cropping systems, Africa, N2O
URN:NBN:urn:nbn:se:slu:epsilon-685
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-685
ID Code:872
Department:(NL, NJ) > Dept. of Soil Sciences
Deposited By: Kristina Röing
Deposited On:14 Jun 2005 00:00
Metadata Last Modified:02 Dec 2014 10:07

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