Magaia, Emilio J.
(2017).
Technologies for improved water use efficiency in small-scale maize production in a semi-arid region.
Diss. (sammanfattning/summary)
Uppsala, Sweden :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2017:53
ISBN 978-91-576-8879-8
eISBN 978-91-576-8880-4
[Doctoral thesis]
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Abstract
Alternative technologies to increase grain maize production under rainfed systems are urgently needed, considering the low grain yield in small-scale farming in countries such as Mozambique. Supplemental irrigation, fertiliser application and tillage methods are valuable available farming technologies. This thesis examined the impact of supplemental irrigation, fertiliser application and three tillage methods (hand hoeing, strip tillage, disc tillage) on maize grain yield. Studies on belowground biomass showed that most roots were concentrated in the upper 20 cm of the soil. Root abundance decreased down the soil profile, which can be genetically derived but also attributable to higher penetration resistance at greater depth. Tillage had a great effect on soil penetration resistance, but little effect on root growth and a limited effect on yield. Root to shoot ratio was high under rainfed conditions, due to low allocation of assimilates to aboveground traits under water stress. Degrees above canopy threshold (DACT, a water stress index) varied from 0 °C (no stress) to 17.1 °C (high stress). It was mainly affected by water supply and was negatively correlated with soil moisture, grain yield, thousand-grain weight and water use efficiency. Water use efficiency ranged from 0.16-0.60 kg m-3 (rainfed) to 0.45-1.09 kg m-3 (irrigated) and was negatively correlated with DACT in both seasons studied. Supplemental irrigation alone resulted in an average maize yield increase of 161% compared with rainfed maize and increased water use efficiency by 79%. Application of 48 kg ha-1 of nitrogen fertiliser alone increased grain yield by 31% compared with no fertiliser and increased water use efficiency by 18%. Crop modelling results suggested that the recommended nitrogen fertiliser rate (120 kg ha-1) for maize in Mozambique is only suitable for irrigated maize or for regions with high, uniform rainfall.
Overall, the work in this thesis reveals scope for improving crop water use efficiency in semi-arid regions through better soil and water management practices.
Authors/Creators: | Magaia, Emilio J. | ||||||||
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Title: | Technologies for improved water use efficiency in small-scale maize production in a semi-arid region | ||||||||
Series Name/Journal: | Acta Universitatis Agriculturae Sueciae | ||||||||
Year of publishing : | 24 May 2017 | ||||||||
Depositing date: | 24 May 2017 | ||||||||
Number: | 2017:53 | ||||||||
Number of Pages: | 92 | ||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala, Sweden | ||||||||
Publisher: | Department of Soil and Environment, Swedish University of Agricultural Sciences | ||||||||
Associated Programs and Other Stakeholders: | SLU - Agricultural Sciences for Global Development > Efficiency in farming systems SLU - Agricultural Sciences for Global Development > Scale issues in relation to food security and poverty alleviation | ||||||||
ISBN for printed version: | 978-91-576-8879-8 | ||||||||
ISBN for electronic version: | 978-91-576-8880-4 | ||||||||
ISSN: | 1652-6880 | ||||||||
Language: | English | ||||||||
Publication Type: | Doctoral thesis | ||||||||
Full Text Status: | Public | ||||||||
Agris subject categories.: | F Plant production > F06 Irrigation F Plant production > F07 Soil cultivation | ||||||||
Subjects: | (A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Agricultural Science (A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science | ||||||||
Agrovoc terms: | maize, supplemental irrigation, rainfed farming, smallholders, water use efficiency, nitrogen, simulation models, tillage, semiarid zoes, mozambique | ||||||||
Keywords: | rainfed, supplemental irrigation, nitrogen, tillage, water use efficiency, leaf temperature, maize, APSIM | ||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-4205 | ||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4205 | ||||||||
ID Code: | 14362 | ||||||||
Faculty: | NL - Faculty of Natural Resources and Agricultural Sciences (until 2013) | ||||||||
Department: | (NL, NJ) > Dept. of Soil and Environment (S) > Dept. of Soil and Environment | ||||||||
External funders: | Swedish International Development Cooperation Agency | ||||||||
Deposited By: | Mr Emilio J Magaia | ||||||||
Deposited On: | 30 May 2017 13:29 | ||||||||
Metadata Last Modified: | 09 Sep 2020 14:17 |
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