Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa
Thesis (MScAgric)--Stellenbosch University, 2025.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Published: |
Stellenbosch : Stellenbosch University
2025
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613842596429824 |
|---|---|
| access_status_str | Open Access |
| author | Mabitsela, Mmakwena Velicia |
| author2 | Tshuma, Flackson |
| author_browse | Mabitsela, Mmakwena Velicia Tshuma, Flackson |
| author_facet | Tshuma, Flackson Mabitsela, Mmakwena Velicia |
| author_sort | Mabitsela, Mmakwena Velicia |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScAgric)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132636 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:42:33.557Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132636 Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa Mabitsela, Mmakwena Velicia Tshuma, Flackson Swanepoel, Pieter Andreas Labuschagne, Johan Stellenbosch University. Faculty of AgriSciences. Dept. of Agronomy. Tillage -- South Africa -- Swartland Soils and nutrition -- South Africa -- Swartland Canola -- Seeds -- Yields Soil amendments -- Management Soil chemical parameters Conservation tillage Plant nutrients UCTD Thesis (MScAgric)--Stellenbosch University, 2025. Mabitsela, M. V. 2025. Effects of Continuous and Rotation Tillage Practices on Stratification of Selected Soil Chemical Parameters and Canola Productivity in the Swartland, South Africa. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/412c5969-9b43-4c82-aea3-cb7e61e59d04 ENGLISH ABSTRACT: Conservation tillage refers to any tillage practices that reduce soil disturbance and leave at least 30% crop residue on the field after planting. Conservation tillage practices such as no-tillage and zero-tillage have been adopted by many farmers globally. However, no-tillage and zero-tillage have common constraints with stratification of chemical parameters and reduced crop yields. Therefore, rotational tillage (involving a phase of tillage and a phase of no-tillage) could be adopted to mitigate the constraints associated with continuous tillage and long-term no-tillage and zero-tillage practices. The study was conducted in the small-grain cropping system of the Swartland region of the Western Cape province, South Africa, on a long-term tillage (48-year) experiment. The first objective investigated the effects of continuous and rotational tillage on the stratification of selected soil chemical parameters. Seven and eight tillage treatments were investigated in the 2022 and 2023 seasons, respectively. For the 2022 season, the tillage treatments included continuous mouldboard (MB), shallow-tine tillage (ST), tine-tillage (TT), no-tillage (NT), and rotational tillage: ST conducted once in two years (NT-ST), ST conducted once in three years (ST-NT-NT), and ST conducted once in every four years (NT-ST-NT-NT). For the 2023 season, the tillage treatments included continuous MB, ST, TT, NT, zero-tillage (ZT), and rotational tillage: ST conducted once in two years (ST-NT), deep-tine (ripper (R)) conducted once in three years (NT-NT-R), and ST conducted once in four years (ST-NT-NT-NT). Soil samples were collected at 0-5, 5-10, 10-15, 15-20, 20-25, 25-35, and 35-45 cm depths. The chemical parameters: soil organic C, pH (KCl), extractable P, cation exchange capacity(CEC), exchangeable K, Mg, Na, and Ca, were assessed. The second objective investigated the effects of continuous tillage treatments MB, ST, TT, NT, and rotational tillage: ST-NT, NT-NT-R, and ST-NT-NT-NT, on canola (Brassica napus) productivity during the 2023 growing season. Canola crop parameters included plant population, aboveground biomass production, seed yield, thousand seed weight, and oil content. The results displayed the reduced stratification of soil organic C, CEC, exchangeable Mg, Ca, and extractable P for the NT-NT-R treatment compared to NT and ZT treatments (P < 0.05). The MB treatment resulted in the highest canola yield (P < 0.05) compared to other treatments except the TT and ST. However, the MB treatment had a lower thousand seed weight and oil content compared to other treatments (P < 0.05). The NT-NT-R achieved higher yields (P < 0.05) relative to NT and ZT and maintained higher seed oil quality compared to MB treatment. The results from this study highlighted the importance of reducing the continuous use of a single tillage practice, because the MB treatment resulted in the depletion of organic matter and the NT and ZT treatments resulted in highly stratified chemical parameters. Furthermore, the results suggest that the NT-NT-R treatment has the potential to reduce the stratification of chemical parameters and increase canola seed yield and quality. However, further research to complete the full four-year rotational tillage with a ripper is essential to validate our results. AFRIKAANSE OPSOMMING: Bewaringbewerking verwys na enige bewerkingspraktyke wat grondversteuring verminder en ten minste 30% oesreste op die land na vestiging laat. Bewaringbewerkingspraktyke soos geenbewerking en nulbewerking is deur baie boere wêreldwyd aangeneem. Geenbewerking en nulbewerking het egter beperkinge soos stratifikasie van chemiese parameters en verlaging in gewasopbrengste. Daarom kan rotasiebewerking (wat 'n fase van bewerking en 'n fase van geenbewerking behels) aangeneem word om die beperkings wat verband hou met deurlopende bewerking en langtermyn geenbewerking en nulbewerking te versag. Die studie is uitgevoer in die kleingraanproduksiestelsel van die Swartland-streek van die Wes-Kaap provinsie, Suid-Afrika, op 'n langtermyn-bewerkingseksperiment (48 jaar). Die eerste doelwit het die effekte van deurlopende en rotasiebewerking op die stratifikasie van geselekteerde grondchemiese parameters ondersoek. Sewe en agt bewerkingsbehandelings is ondersoek in onderskeidelik die 2022- en 2023- groeiseisoene. Vir die 2022-seisoen het die bewerkingsbehandelings deurlopende skaarploeg (MB), vlak- tandbewerking (ST), tandbewerking (TT), geenbewerking (NT), en rotasiebewerking ingesluit: ST uitgevoer een keer in twee jaar (NT-ST), ST uitgevoer een keer in drie jaar (ST-NT-NT), en ST uitgevoer een keer in elke vier jaar (NT-ST-NT-NT). Vir die 2023-seisoen het die bewerkingsbehandelings deurlopende MB, ST, TT, NT, nulbewerking (ZT), en rotasiebewerking ingesluit: ST uitgevoer een keer in twee jaar (ST-NT), diep-tand (ripper (R)) uitgevoer een keer in drie jaar (NT-NT-R), en ST uitgevoer een keer in vier jaar (ST-NT-NT-NT). Grondmonsters is op 0-5, 5-10, 10-15, 15-20, 20-25, 25-35, en 35-45 cm dieptes versamel. Die chemiese parameters wat geëvalueer is, sluit in: grondorganiese koolstof (C), pH (KCl), ekstraheerbare fosfor (P), kation-uitruilkapasiteit (KUK), uitruilbare kalium (K), magnesium (Mg), natrium (Na), en kalsium (Ca). Die tweede doelwit het die effekte van deurlopende bewerkingsbehandelings MB, ST, TT, NT, en rotasiebewerking: ST-NT, NT-NT-R, en ST-NT-NT-NT, op canolaproduktiwiteit (Brassica napus) tydens die 2023-groeiseisoen ondersoek. Canola gewasparameters het plantpopulasie, bogrondse biomassa-produksie, saadopbrengs, duisend-saadmassa, en olie-inhoud ingesluit. Die resultate het getoon dat die NT-NT-R behandeling 'n verminderde stratifikasie van grond organiese C, KUK, uitruilbare Mg, Ca, en ekstrakteerbare P gehad het in vergelyking met die NT- en ZT- behandelings (P < 0.05). Die MB-behandeling het die hoogste canola-opbrengs (P < 0.05) gelewer in vergelyking met ander behandelings, behalwe TT en ST. Nietemin het die MB-behandeling 'n laer duisend- saadmassa en olie-inhoud gehad in vergelyking met ander behandelings (P < 0.05). Die NT-NT-R het hoër opbrengste (P < 0.05) behaal relatief tot NT en ZT en het hoër saadoliegehalte gehandhaaf in vergelyking met die MB-behandeling. Die resultate van hierdie studie het die belangrikheid om die deurlopende gebruik van 'n enkele bewerkingspraktyk te verminder, beklemtoon, aangesien die MB-behandeling gelei het tot die uitputting van organiese materiaal en die NT- en ZT-behandelings gelei het tot sterk stratifikasie van chemiese parameters. Verder dui die resultate daarop dat die NT-NT-R behandeling die potensiaal het om die stratifikasie van chemiese parameters te verminder en canola saadopbrengs en -gehalte te verhoog. Nietemin is verdere navorsing nodig om die volle vierjaar-rotasiebewerking met 'n ripper te voltooi en ons resultate te bekragtig. Masters 2025-06-12T07:23:17Z 2025-06-12T07:23:17Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132636 Stellenbosch University xii, 90 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Tillage -- South Africa -- Swartland Soils and nutrition -- South Africa -- Swartland Canola -- Seeds -- Yields Soil amendments -- Management Soil chemical parameters Conservation tillage Plant nutrients UCTD Mabitsela, Mmakwena Velicia Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa |
| title | Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa |
| title_full | Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa |
| title_fullStr | Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa |
| title_full_unstemmed | Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa |
| title_short | Effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the Swartland, South Africa |
| title_sort | effects of continuous and rotation tillage practices on stratification of selected soil chemical parameters and canola productivity in the swartland south africa |
| topic | Tillage -- South Africa -- Swartland Soils and nutrition -- South Africa -- Swartland Canola -- Seeds -- Yields Soil amendments -- Management Soil chemical parameters Conservation tillage Plant nutrients UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132636 |
| work_keys_str_mv | AT mabitselammakwenavelicia effectsofcontinuousandrotationtillagepracticesonstratificationofselectedsoilchemicalparametersandcanolaproductivityintheswartlandsouthafrica |