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Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM
Dissertation (MSc)--University of Pretoria, 2018.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2019
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| _version_ | 1867613523100565505 |
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| access_status_str | Open Access |
| author2 | Van der Laan, Michael |
| author_browse | Van der Laan, Michael |
| author_facet | Van der Laan, Michael |
| collection | Thesis |
| dc_rights_str_mv | © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2018. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/72793 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:29.889Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/72793 Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM Van der Laan, Michael u16109270@tuks.co.za Prof R. van Antwerpen Maseko, Simphiwe Khulekani UCTD Dissertation (MSc)--University of Pretoria, 2018. Maize and sugarcane production has been threatened by declining soil quality due to long-term unsustainable management practices, which have increased the reliance on inorganic fertilization. This study reports on long-term yields and soil organic matter (SOM) trends and further evaluates nitrogen (N) leaching losses from maize and sugarcane as affected by inorganic fertilization and residue management practices. The study aims to investigate the effects of long-term management practices on maize and sugarcane monocropping systems in South Africa, through the application of long-term monitoring data and mechanistic modelling. Data from the University of Pretoria’s Hillcrest Campus Experimental Farm long-term maize trial and SASRI long-term sugarcane trial, in Mt Edgecombe were used. The APSIM model was calibrated and validated using long-term yield and SOM data, and the model was further used to estimate N leaching and evaluate management scenarios that can be used for more sustainable maize and sugarcane production. Although the model could be well calibrated for simulating maize growth for 2016/2017 season, long-term yields were not always accurately estimated. The results indicated a declining trend in maize yields and SOM over the years, with greater decline in the control treatment. APSIM estimated higher drainage in the maize control but higher N leaching in the fertilized NPK treatment. A manure application scenario proved to be more sustainable for long-term maize production, although it requires a good inorganic N fertilizer management programme to minimize N leaching losses. In sugarcane, observed and simulated results indicated that fertilizer application increased yields, and mulching was the best residue management practice for reducing SOM decline. The combination of fertilization and mulching produced higher long-term sugarcane yields and retained SOM content better, but it also led to the highest NO3-N leaching. Modelling reduced fertilizer application did not result in a significant reduction in yield, indicating that mineralized N from SOM can be able to satisfy a proportion of crop N demand, so fertilizer application recommendations should also account for mineralized N to minimize N losses. This can be the best way of improving N management in sugarcane cropping systems, thus reducing inputs, increasing profits and minimizing losses that can lead to environmental pollution. Modelling has the potential of helping us understand the complex long-term C and N dynamics in cropping systems and identification of ways to improve management practices. Plant Production and Soil Science MSc Unrestricted 2019-12-13T08:08:13Z 2019-12-13T08:08:13Z 2019/09/05 2018 Dissertation Maseko, SK 2018, Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/72793> S2019 http://hdl.handle.net/2263/72793 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM |
| title | Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM |
| title_full | Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM |
| title_fullStr | Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM |
| title_full_unstemmed | Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM |
| title_short | Simulating long-term carbon and nitrogen dynamics of South African maize (Zea mays l.) and sugarcane (Saccharum officinarum l.) cropping systems with APSIM |
| title_sort | simulating long term carbon and nitrogen dynamics of south african maize zea mays l and sugarcane saccharum officinarum l cropping systems with apsim |
| topic | UCTD |
| url | http://hdl.handle.net/2263/72793 |