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Subsoil improvement for sustainable intensification : impact of loosening with straw incorporation or liming on subsoil properties, crop performance and water quality

Getahun, Gizachew Tarekegn (2021). Subsoil improvement for sustainable intensification : impact of loosening with straw incorporation or liming on subsoil properties, crop performance and water quality. Diss. (sammanfattning/summary) Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880
ISBN 978-91-7760-764-9
eISBN 978-91-7760-765-6
[Doctoral thesis]

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Abstract

Subsoil has a high capacity for nutrient and water retention, but arable subsoil is often nutrient poor, carbon-deficient and compacted, affecting both root growth and yield. In field and lysimeter experiments, this thesis investigated the effects of subsoil loosening and loosening with cereal straw incorporation (24-60 Mg ha-1) (loosening + straw) on crop yield, soil properties (bulk density, penetration resistance, moisture characteristics) and leaching. A rectangular metal tube welded behind each tine of a deep loosener was used to inject straw as a slurry in the field, while subsoil was loosened and mixed manually with milled straw in lysimeter studies. In laboratory experiments, subsoil was limed with different amounts of CaCO3 and CaO to increase soil pH from 7.0 to 7.5, 8.0 and 8.4 and incubated for 22 months to examine changes in soil structural stability and dissolved reactive phosphorus. Field subsoil loosening + straw significantly increased soil organic carbon, total nitrogen and water holding capacity. It also decreased bulk density, from around 1.5 Mg m-3 in the control to about 1.0 Mg m-3. The effects of loosening + straw persisted for at least three years, but loosening alone had weak and short-lived effects. Loosening + straw significantly increased grain yield in the first cropping season (6% higher than the control), but not in the following two years. Nitrogen balance calculations of lysimeters showed that short-term nitrogen losses were lowest in the subsoil loosening + straw treatment and that nitrogen leaching was reduced by about 62%. In incubations, subsoil liming decreased clay dispersion. Wet aggregate stability and concentration of dissolved reactive phosphorus increased and peaked around pH 7.8 and 7.5, respectively. Combining loosening with straw incorporation into subsoil appeared to improve soil properties and water quality, but not crop yield on the experimental soil. On other soil types, this practice may have more beneficial effects.

Authors/Creators:Getahun, Gizachew Tarekegn
Title:Subsoil improvement for sustainable intensification : impact of loosening with straw incorporation or liming on subsoil properties, crop performance and water quality
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2021
Number:2021:43
Number of Pages:89
Publisher:Department of Soil and Environment, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-7760-764-9
ISBN for electronic version:978-91-7760-765-6
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Article category:Other scientific
Version:Published version
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science
Keywords:aggregate stability, grain yield, immobilisation, lysimeter, organic matter, N-balance, N-leaching, soil pH
URN:NBN:urn:nbn:se:slu:epsilon-p-111941
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-p-111941
ID Code:23746
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Soil and Environment
(S) > Dept. of Soil and Environment
Deposited By: SLUpub Connector
Deposited On:24 May 2021 10:43
Metadata Last Modified:26 May 2021 07:02

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