- Title
- Tillage and crop rotation effects on selected soil properties and wheat yield in a short term field experiment in the Eastern Cape province, South Africa
- Creator
- Mtyobile, Mxolisi
- Subject
- Crop rotation -- South Africa -- Eastern Cape Cropping systems -- South Africa -- Eastern Cape
- Date Issued
- 2017
- Date
- 2017
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10353/13414
- Identifier
- vital:39659
- Description
- Severe land degradation associated with current conventional production systems have resulted in low production amongst the small scale farmers in the Eastern Cape. Inappropriate management practices cause depletion of organic matter and other essential nutrients leading to a decline in crop productivity. There is growing evidence that conservation agriculture (CA) practices involving no-tillage (NT) coupled with crop rotation and surface residue retention increases soil organic carbon (SOC) and other essential nutrients and therefore has potential to alleviate soil quality deterioration. A study was carried out to investigate the effects of tillage and crop rotation with crop residue retention on selected soil properties and on wheat yield in the Alice Jozini ecotope of the Eastern Cape. Specific objectives were to determine (i) the effect of crop rotation and tillage on soil SOC, NH4, NO3, total N, P, K, Ca, Mg, Zn, soil pH and EC distribution at 0-5 cm, 5 cm -10 cm, 10 cm-20 cm (ii) the effect of crop rotation and tillage on soil bulk density, porosity and on soil water content (iii) the effect of crop rotation and tillage on wheat biomass and grain yield. Treatments were arranged as a split-split plot in a randomized complete block design with three replicates. Tillage treatments included no-tillage (NT) and conventional tillage (CT) and were applied on the main plots while crop rotation treatments were applied as subplots. Crop residue retention treatments were applied as sub-sub plots. The rotational treatments were maize-fallow-maize (MFM), maize-fallow-soybean (MFS), maize-wheat-maize (MWM) and maize-wheat-soybean (MWS). However, the current study focused on tillage and crop rotation treatments under residue retention to give 8 treatments. Data from the field trials showed that NT with residue retention had significantly (p < 0.05) higher SOC, Total N, P, K, Ca and EC relative to CT. The MWS rotation under no-tillage (NT) with residue retention followed by MFS resulted in the progressive improvement in soil nutrient status. The correlations of SOC with various soil nutrients under study showed that the nature of the relationships between SOC and nutrient availability was consistent. Results on soil physical parameters showed that tillage had no significant effect (p > 0.05) on soil bulk density (ρb) and porosity whereas a significant effect on soil water content under NT was observed. Crop rotation had no significant effects (p > 0.05) on soil bulk density, porosity and soil moisture across the tillage treatments. The MWS rotation registered an increase in soil porosity in comparison with the MWM and MFM. Tillage x crop rotation interaction effects were significant (p < 0.05) on the measured porosity and soil water content. Soil bulk density showed negative correlation with soil porosity and soil water content (SWC) whereas porosity had a positive correlation with SWC. On yield parameters, results revealed that no significant (P>0.05) interaction of main effects with respect to wheat biomass and grain yield. Tillage had a significant (P<0.05) effect on wheat biomass only in season 2. Tillage and crop rotation effects were not significant (P>0.05) with regards to grain yield throughout the experimental period. Higher grain wheat biomass and grain yield were found in MWS rotation under NT with surface residue retention although not statistically significant. Correlation analysis revealed that wheat yield was positively correlated to SOC, P, and Total N. Therefore, combination of NT with MWS rotation with residue retention has the potential to significantly improve soil chemical properties and wheat grain yield whereas MWM followed by MWS crop rotation under NT showed an increase in soil porosity and soil water content.
- Format
- 132 leaves
- Format
- Publisher
- University of Fort Hare
- Publisher
- Faculty of Science and Agriculture
- Language
- English
- Rights
- University of Fort Hare
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UFH Department of Agronomy
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | MSc Agric (Crop Science) MTYOBILE.pdf | 1 MB | Adobe Acrobat PDF | View Details Download |