Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.2001597
KA Seetseng, L. van Rensburg, J. Barnard, C. du Preez
In South Africa canola (Brassica napus L.) is cultivated in rotation with wheat under winter rainfall in the Western Cape Province. Expansion of the crop to the other eight provinces is advocated to reduce a shortage of locally produced plant oils. Moreover, canola can serve as a rotational crop for wheat in the summer rainfall provinces. In the central Free State, agronomic information for canola production is lacking. An experiment with a line source sprinkler irrigation system was conducted to establish the influence of water application levels (175, 233, 295, 351 and 420 mm) in combination with plant densities (25, 50, 75, 100 and 125 plants m−2) on yield responses, yield components and growth parameters of canola. Seed (653–4653 kg ha−1) and stover (1983–6733 kg ha−1) yields induced by the treatment combinations proved that canola has a high level of plasticity. Over the full range of water application levels, highest seed and biomass yields were realised at densities of 25 and 75 plants m−2, respectively. The compensation of yields at lower plant densities was due to the production of more branches, pods and seeds per plant. Under full irrigation, densities of 25 and 75 plants m−2 are optimal for seed and biomass production, respectively.
在南非，在西开普省，油菜(油菜L.)在冬季降雨下与小麦轮作种植。人们提倡将这种作物扩大到其他8个省份，以减少当地生产的植物油的短缺。此外，在夏季多雨的省份，油菜可以作为小麦的轮作作物。在自由邦中部，缺乏油菜籽生产的农艺信息。通过线源喷灌系统试验，研究了施水量(175、233、295、351和420 mm)和种植密度(25、50、75、100和125株m−2)对油菜产量响应、产量构成和生长参数的影响。处理组合诱导的种子产量(653 ~ 4653 kg ha - 1)和干料产量(1983 ~ 6733 kg ha - 1)表明油菜具有较高的可塑性。在整个施水量范围内，种子和生物量产量最高的密度分别为25株和75株m - 2。低密度下产量的补偿是由于单株产生更多的枝、荚和种子。在充分灌溉条件下，25株m−2和75株m−2的密度对种子和生物量产量最适宜。
{"title":"Influence of water application levels and plant densities on the plasticity of canola in the central Free State, South Africa","authors":"KA Seetseng, L. van Rensburg, J. Barnard, C. du Preez","doi":"10.1080/02571862.2021.2001597","DOIUrl":"https://doi.org/10.1080/02571862.2021.2001597","url":null,"abstract":"In South Africa canola (Brassica napus L.) is cultivated in rotation with wheat under winter rainfall in the Western Cape Province. Expansion of the crop to the other eight provinces is advocated to reduce a shortage of locally produced plant oils. Moreover, canola can serve as a rotational crop for wheat in the summer rainfall provinces. In the central Free State, agronomic information for canola production is lacking. An experiment with a line source sprinkler irrigation system was conducted to establish the influence of water application levels (175, 233, 295, 351 and 420 mm) in combination with plant densities (25, 50, 75, 100 and 125 plants m−2) on yield responses, yield components and growth parameters of canola. Seed (653–4653 kg ha−1) and stover (1983–6733 kg ha−1) yields induced by the treatment combinations proved that canola has a high level of plasticity. Over the full range of water application levels, highest seed and biomass yields were realised at densities of 25 and 75 plants m−2, respectively. The compensation of yields at lower plant densities was due to the production of more branches, pods and seeds per plant. Under full irrigation, densities of 25 and 75 plants m−2 are optimal for seed and biomass production, respectively.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41419878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1970831
Avhurengwi Shirley Mathelemuse, K. Yobo, M. Truter, P. Steyn, M. Kena, R. Sutherland
Brown leaf spot caused by Alternaria alternata (Fries) Keissler is one of the most devastating fungal diseases of potato. Management of this disease relies mostly on fungicide applications. However, fungicides are becoming less effective due to the development of fungal resistance to specific chemicals. Additionally, there is limited information on resistance in potato cultivars in South Africa against brown leaf spot. This study aims to evaluate ten commercial potato cultivars for brown leaf spot resistance using detached leaf, tuber and whole plant screening techniques under controlled conditions. The experiment was conducted in 2016 and repeated in 2017. The whole plant assay showed that Labadia, Almera, Sifra, Mondeo, Up-To-Date and Lanorma are resistant to brown spot. Resistance levels in Labadia, Almera, Sifra and Up-To-Date were consistent in the 2016 and 2017 experiments. The detached leaf assay showed Almera, Sifra, Up-To-Date and Mondeo as moderately resistant, while Innovator, Mondial and Markies were moderately susceptible. However, in the tuber assay all cultivars were highly susceptible. Cultivar resistance varied based on the screening technique used, although results suggest that the detached leaf and whole plant assays could be used in potato disease screening programs.
{"title":"Assessing resistance levels of potato cultivars in South Africa against Alternaria alternata","authors":"Avhurengwi Shirley Mathelemuse, K. Yobo, M. Truter, P. Steyn, M. Kena, R. Sutherland","doi":"10.1080/02571862.2021.1970831","DOIUrl":"https://doi.org/10.1080/02571862.2021.1970831","url":null,"abstract":"Brown leaf spot caused by Alternaria alternata (Fries) Keissler is one of the most devastating fungal diseases of potato. Management of this disease relies mostly on fungicide applications. However, fungicides are becoming less effective due to the development of fungal resistance to specific chemicals. Additionally, there is limited information on resistance in potato cultivars in South Africa against brown leaf spot. This study aims to evaluate ten commercial potato cultivars for brown leaf spot resistance using detached leaf, tuber and whole plant screening techniques under controlled conditions. The experiment was conducted in 2016 and repeated in 2017. The whole plant assay showed that Labadia, Almera, Sifra, Mondeo, Up-To-Date and Lanorma are resistant to brown spot. Resistance levels in Labadia, Almera, Sifra and Up-To-Date were consistent in the 2016 and 2017 experiments. The detached leaf assay showed Almera, Sifra, Up-To-Date and Mondeo as moderately resistant, while Innovator, Mondial and Markies were moderately susceptible. However, in the tuber assay all cultivars were highly susceptible. Cultivar resistance varied based on the screening technique used, although results suggest that the detached leaf and whole plant assays could be used in potato disease screening programs.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46559545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1969693
S. Dube, P. Muchaonyerwa, F. Mapanda, J. Hughes
Liquid waste (sludge water (SW)) from treatment of drinking water contains impurities which pose disposal challenges. Irrigation with SW could be a solution for the Morton Jaffray Water Works. This study was conducted to determine the effects of SW dilution on aluminium (Al) and manganese (Mn) concentrations in (a) leachates from columns with either clay or a sandy loam soil and (b) different depths in the columns. The columns were leached with tap water (control) and 25, 50, 75 and 100% of the original SW concentration and the leachates were analysed for pH, electrical conductivity (EC), Al, and Mn. The sectioned soils (0–5, 5–10, 10–15 cm depths) were analysed for pH, exchangeable acidity, extractable Mn and total Al and Mn. Leaching with undiluted SW significantly increased EC and Al and Mn concentrations and lowered pH in leachates of the first four and two leaching events in the clay and sandy loam soils, respectively. The last two to four leaching events released additional Mn. Higher SW concentrations significantly increased retention of Mn, Al, extractable Mn and acidity, and lowered pH in the soils. In practice, irrigation with SW may retain the pollutants and acidify the soil, increasing Mn mobility, potentially causing leaching and phytotoxicity.
{"title":"Aluminium and manganese leaching and retention in two contrasting soils treated with aluminium-based sludge water in a column experiment","authors":"S. Dube, P. Muchaonyerwa, F. Mapanda, J. Hughes","doi":"10.1080/02571862.2021.1969693","DOIUrl":"https://doi.org/10.1080/02571862.2021.1969693","url":null,"abstract":"Liquid waste (sludge water (SW)) from treatment of drinking water contains impurities which pose disposal challenges. Irrigation with SW could be a solution for the Morton Jaffray Water Works. This study was conducted to determine the effects of SW dilution on aluminium (Al) and manganese (Mn) concentrations in (a) leachates from columns with either clay or a sandy loam soil and (b) different depths in the columns. The columns were leached with tap water (control) and 25, 50, 75 and 100% of the original SW concentration and the leachates were analysed for pH, electrical conductivity (EC), Al, and Mn. The sectioned soils (0–5, 5–10, 10–15 cm depths) were analysed for pH, exchangeable acidity, extractable Mn and total Al and Mn. Leaching with undiluted SW significantly increased EC and Al and Mn concentrations and lowered pH in leachates of the first four and two leaching events in the clay and sandy loam soils, respectively. The last two to four leaching events released additional Mn. Higher SW concentrations significantly increased retention of Mn, Al, extractable Mn and acidity, and lowered pH in the soils. In practice, irrigation with SW may retain the pollutants and acidify the soil, increasing Mn mobility, potentially causing leaching and phytotoxicity.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44732981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1970832
L. Myeni, M. Moeletsi, AD Clulow
Data discontinuity is the major challenge that hinders the integrity of datasets from the sparse soil moisture monitoring networks in developing countries. In this study, a simplified, multi-layered soil water balance model to estimate daily soil moisture at point-scale from standard weather data and minimal physical soil properties was developed. The model requires values for soil water retentivity properties such as wilting point, field capacity and saturation of each soil layer. It also requires measurements or estimates of reference evapotranspiration (ETo ) in addition to rainfall as climate inputs. The developed model was evaluated using point-scale in-situ soil moisture measurements acquired over a minimum of two years from three well-calibrated stations representing different soil types and climatic conditions in South Africa. The results indicate that the proposed model was capable of estimating total soil moisture content at all three sites, with coefficient of determination (r 2) values greater than 0.84, index of agreement (d) values greater than 0.95 and root mean square error (RMSE) values less than 7.30 mm. The findings of this study suggest that the proposed model can be reliably used for daily estimation of soil moisture at point-scale using climate data and minimal soil physical properties, to fill in gaps, and to extend datasets in locations facing data-discontinuity.
{"title":"Development and validation of an operational multi-layered model for estimation of soil moisture at point-scale in South Africa","authors":"L. Myeni, M. Moeletsi, AD Clulow","doi":"10.1080/02571862.2021.1970832","DOIUrl":"https://doi.org/10.1080/02571862.2021.1970832","url":null,"abstract":"Data discontinuity is the major challenge that hinders the integrity of datasets from the sparse soil moisture monitoring networks in developing countries. In this study, a simplified, multi-layered soil water balance model to estimate daily soil moisture at point-scale from standard weather data and minimal physical soil properties was developed. The model requires values for soil water retentivity properties such as wilting point, field capacity and saturation of each soil layer. It also requires measurements or estimates of reference evapotranspiration (ETo ) in addition to rainfall as climate inputs. The developed model was evaluated using point-scale in-situ soil moisture measurements acquired over a minimum of two years from three well-calibrated stations representing different soil types and climatic conditions in South Africa. The results indicate that the proposed model was capable of estimating total soil moisture content at all three sites, with coefficient of determination (r 2) values greater than 0.84, index of agreement (d) values greater than 0.95 and root mean square error (RMSE) values less than 7.30 mm. The findings of this study suggest that the proposed model can be reliably used for daily estimation of soil moisture at point-scale using climate data and minimal soil physical properties, to fill in gaps, and to extend datasets in locations facing data-discontinuity.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47575124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.1080/02571862.2021.1958939
Vhuthu Ndou, E. Phiri, F. H. Eksteen, P. Pieterse
Globally glyphosate is the most widely used herbicide. The alternative in many cropping situations is paraquat. After many years of success, neither herbicide could control plantago (Plantago lanceolata L., also ‘English plantain’) in Robertson. A survey was carried out by sending a questionnaire to agrichemical personnel to document the areas with poor plantago control using glyphosate and paraquat in the Western Cape province of South Africa. Recipients were asked to list localities with plantago not eliminated by glyphosate and paraquat, plantago populations that are not controlled by other herbicides apart from glyphosate and paraquat, other herbicides apart from glyphosate and paraquat that eliminate plantago, the history of herbicides applied in those areas and the total number of hectares involved. Survey data were obtained for 21 areas, which spanned over 6 583 ha. There were minimal differences in the type of herbicides applied in the different areas across the province. Most of the respondents reported that both glyphosate and paraquat were failing to control plantago. It appears as if the occurrence of difficult-to-control plantago is more widespread than initially thought. In future, a more detailed survey encompassing the entire country should be carried out to assess the extent of this problem. This will allow weed management strategies to be prioritised to deal with the troublesome plantago weed.
{"title":"Occurrence of putatively resistant plantago in the winter rainfall region of South Africa: a survey","authors":"Vhuthu Ndou, E. Phiri, F. H. Eksteen, P. Pieterse","doi":"10.1080/02571862.2021.1958939","DOIUrl":"https://doi.org/10.1080/02571862.2021.1958939","url":null,"abstract":"Globally glyphosate is the most widely used herbicide. The alternative in many cropping situations is paraquat. After many years of success, neither herbicide could control plantago (Plantago lanceolata L., also ‘English plantain’) in Robertson. A survey was carried out by sending a questionnaire to agrichemical personnel to document the areas with poor plantago control using glyphosate and paraquat in the Western Cape province of South Africa. Recipients were asked to list localities with plantago not eliminated by glyphosate and paraquat, plantago populations that are not controlled by other herbicides apart from glyphosate and paraquat, other herbicides apart from glyphosate and paraquat that eliminate plantago, the history of herbicides applied in those areas and the total number of hectares involved. Survey data were obtained for 21 areas, which spanned over 6 583 ha. There were minimal differences in the type of herbicides applied in the different areas across the province. Most of the respondents reported that both glyphosate and paraquat were failing to control plantago. It appears as if the occurrence of difficult-to-control plantago is more widespread than initially thought. In future, a more detailed survey encompassing the entire country should be carried out to assess the extent of this problem. This will allow weed management strategies to be prioritised to deal with the troublesome plantago weed.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47932518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.1080/02571862.2021.1956609
P. Parehwa, G. Linsley-Noakes, J. Jordaan, J. Pauw
In South Africa, strawberry Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier growers have not been able to extend the growing season and produce strawberries year-round primarily due to the types of cultivar available and climatic limitations. The objective of the study was to determine the effects of planting date- and day-neutral strawberry varieties on plant growth, yield and quality in the south-eastern region of the Western Cape. The experiment was conducted as a split-plot design with three replications. Planting dates were the whole plot treatments, while varieties constituted the sub-plot treatments. The sub-plot treatments were laid out in a randomised complete block design. Three day-neutral strawberry varieties, ‘Monterey’, ‘San Andreas’ and ‘Albion’ were planted at 30-day intervals from April to September for the 2018/2019 season in standard coir grow-bags at a density of 75 000 ha−1. ‘Monterey’ significantly outperformed ‘San Andreas’ which in turn significantly (p < 0.05) outperformed ‘Albion’ for crown number, flower number, yield and fruit size. ‘San Andreas’ produced significantly fewer runners than ‘Monterey’ and ‘Albion’. ‘Albion’ produced significantly higher total soluble solids followed by ‘Monterey’ and ‘San Andreas’. It was concluded that ‘Monterey’ planted in April and ‘San Andreas’ planted in August, can be used to extend the harvest season.
在南非，草莓Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier种植者无法延长生长季节并全年生产草莓，主要是由于可用的品种类型和气候限制。该研究的目的是确定种植日期和日中性草莓品种对西开普省东南部地区植物生长、产量和质量的影响。试验采用裂区设计，重复3次。种植日期为整块处理，品种为分块处理。子图处理采用随机完全区设计。在2018/2019季节，从4月到9月，在标准椰壳种植袋中，以7.5万公顷的密度，每隔30天种植“蒙特雷”、“圣安德烈亚斯”和“阿尔比恩”三个日间中性草莓品种。“蒙特雷”在冠数、花数、产量和果实大小方面显著优于“圣安德烈亚斯”(p < 0.05)，而“圣安德烈亚斯”又显著优于“阿尔比恩”。“圣安德烈亚斯”产生的跑步者明显少于“蒙特雷”和“阿尔比恩”。“阿尔比恩”产生的可溶性固体总量显著高于“蒙特雷”和“圣安德烈亚斯”。结论是，“蒙特雷”在4月种植，“圣安德烈亚斯”在8月种植，可以用来延长收获季节。
{"title":"Cultivar and planting date effects on the growth, yield and quality of strawberries in the Western Cape, South Africa","authors":"P. Parehwa, G. Linsley-Noakes, J. Jordaan, J. Pauw","doi":"10.1080/02571862.2021.1956609","DOIUrl":"https://doi.org/10.1080/02571862.2021.1956609","url":null,"abstract":"In South Africa, strawberry Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier growers have not been able to extend the growing season and produce strawberries year-round primarily due to the types of cultivar available and climatic limitations. The objective of the study was to determine the effects of planting date- and day-neutral strawberry varieties on plant growth, yield and quality in the south-eastern region of the Western Cape. The experiment was conducted as a split-plot design with three replications. Planting dates were the whole plot treatments, while varieties constituted the sub-plot treatments. The sub-plot treatments were laid out in a randomised complete block design. Three day-neutral strawberry varieties, ‘Monterey’, ‘San Andreas’ and ‘Albion’ were planted at 30-day intervals from April to September for the 2018/2019 season in standard coir grow-bags at a density of 75 000 ha−1. ‘Monterey’ significantly outperformed ‘San Andreas’ which in turn significantly (p < 0.05) outperformed ‘Albion’ for crown number, flower number, yield and fruit size. ‘San Andreas’ produced significantly fewer runners than ‘Monterey’ and ‘Albion’. ‘Albion’ produced significantly higher total soluble solids followed by ‘Monterey’ and ‘San Andreas’. It was concluded that ‘Monterey’ planted in April and ‘San Andreas’ planted in August, can be used to extend the harvest season.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41694798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.1080/02571862.2021.1962421
Patrick Nyambo, B. Thengeni, C. Chiduza, T. Araya
Soil and crop productivity cannot be maintained unless declining soil fertility is replenished. A three-year factorial experiment using a split-split-plot design, replicated three times, was used to evaluate the response of pH, electrical conductivity, exchangeable cations (Ca, Mg, K and Na), microbial biomass carbon, total nitrogen and total carbon to conservation agriculture in the Eastern Cape, South Africa. The whole plot factors were conservation tillage and no tillage, the sub-plot factors three crop rotation practices (i.e. maize → oat → maize; maize → vetch → maize and maize → fallow → maize) and the sub-sub-plot factors three residue management practices (viz. residue retention; residue removal and biochar amendment). Soil pH and EC were not affected (p > 0.05) by these agricultural practices after 3 years. Magnesium (p < 0.05) and potassium (p < 0.01) were significantly affected by tillage at 0–5 cm depth. The tillage x crop rotation x residue management interaction was only significant (p < 0.01) for MBC at a depth of 0–5 cm depth. Interactions of tillage x crop rotation (p < 0.001) and crop rotation x residue management (p < 0.0001) were also significant. After three years, conservation agriculture resulted in net increases in total carbon, total nitrogen and MBC concentrations compared to conventional agricultural practices.
{"title":"Tillage, crop rotation, residue management and biochar influence on soil chemical and biological properties","authors":"Patrick Nyambo, B. Thengeni, C. Chiduza, T. Araya","doi":"10.1080/02571862.2021.1962421","DOIUrl":"https://doi.org/10.1080/02571862.2021.1962421","url":null,"abstract":"Soil and crop productivity cannot be maintained unless declining soil fertility is replenished. A three-year factorial experiment using a split-split-plot design, replicated three times, was used to evaluate the response of pH, electrical conductivity, exchangeable cations (Ca, Mg, K and Na), microbial biomass carbon, total nitrogen and total carbon to conservation agriculture in the Eastern Cape, South Africa. The whole plot factors were conservation tillage and no tillage, the sub-plot factors three crop rotation practices (i.e. maize → oat → maize; maize → vetch → maize and maize → fallow → maize) and the sub-sub-plot factors three residue management practices (viz. residue retention; residue removal and biochar amendment). Soil pH and EC were not affected (p > 0.05) by these agricultural practices after 3 years. Magnesium (p < 0.05) and potassium (p < 0.01) were significantly affected by tillage at 0–5 cm depth. The tillage x crop rotation x residue management interaction was only significant (p < 0.01) for MBC at a depth of 0–5 cm depth. Interactions of tillage x crop rotation (p < 0.001) and crop rotation x residue management (p < 0.0001) were also significant. After three years, conservation agriculture resulted in net increases in total carbon, total nitrogen and MBC concentrations compared to conventional agricultural practices.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47612173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.1080/02571862.2021.1959660
S. Adjei-Nsiah, J. K. Ahiakpa, K. Gyan, F. Kanampiu
We conducted on-farm trials in the southern Guinea savannah of Ghana in 2016 and 2017 to evaluate soyabean response to three fertiliser blends to guide farmers towards profitable adoption of appropriate phosphorus fertiliser blend for improved soyabean production. Old Yara Legume, New Yara Legume and Triple Superphosphate fertiliser blends were evaluated. In both years, the phosphorus fertiliser blends were evaluated in a Randomised Complete Block Design with 20, 30, and 40 kg P ha−1 application rates together with control. Phosphorus fertiliser application increased soyabean yields by 1 070 kg ha−1. In 2016, fertiliser blend use efficiency ranged from 2.9 kg grain per kg fertiliser blend applied with the New Yara Legume applied at 40 kg P ha−1 to 7.4 kg grain per kg fertiliser blend applied with the Triple Superphosphate applied at 40 kg P ha−1 with significant differences between treatments. In 2017, blend use efficiency ranged from 2.5 kg grain per kg fertiliser blend applied with Old Yara Legume applied at 40 kg P ha−1 to 9.2 kg grain per kg fertiliser blend applied with the Triple Superphosphate applied at 40 kg P ha−1 with significant differences between treatments. However, phosphorus use efficiency did not significantly differ between the different treatments both in the 2016 and 2017 trials. In both 2016 and 2017 trials, the highest benefit cost ratio was attained at the lowest application rate for all the three fertiliser blends suggesting the need to review the current application rate of 30 kg P fertiliser ha−1 promoted in northern Ghana. Furthermore, the provision of credit and/or subsidy for farmers by the government is required to enable uptake and utilisation of fertilisers by farmers.
我们于2016年和2017年在加纳南部几内亚大草原进行了农场试验，以评估大豆对三种肥料混合物的反应，以指导农民采用适当的磷肥混合物来提高大豆产量。对老亚拉豆科、新亚拉豆科和三元过磷酸钾混交肥进行了评价。在这两年中，采用随机完全区组设计，分别以20、30和40 kg P ha - 1施用量以及对照对磷肥混合物进行评估。施用磷肥可使大豆产量增加1 070公斤/公顷。2016年，混合肥料的利用效率为每公斤2.9公斤粒与施用40公斤磷- 1的新雅拉豆科作物混合肥料，每公斤7.4公斤粒与施用40公斤磷- 1的三元过磷酸钙混合肥料，处理之间存在显著差异。2017年，混合肥料的利用效率为每公斤2.5公斤粒与40公斤磷- 1的老雅拉豆科作物混合施用，每公斤9.2公斤粒与40公斤磷- 1的三磷酸混合施用，处理之间存在显著差异。然而，在2016年和2017年的试验中，不同处理之间的磷利用效率没有显著差异。在2016年和2017年的试验中，所有三种肥料混合物在最低施用量下获得了最高的效益成本比，这表明有必要审查目前在加纳北部推广的30公斤磷肥每公顷的施用量。此外，需要政府向农民提供信贷和/或补贴，以使农民能够吸收和利用肥料。
{"title":"Influence of phosphorus fertiliser blends on grain yield, nutrient concentration, and profitability of soyabeans in the southern Guinea Savannah of Ghana","authors":"S. Adjei-Nsiah, J. K. Ahiakpa, K. Gyan, F. Kanampiu","doi":"10.1080/02571862.2021.1959660","DOIUrl":"https://doi.org/10.1080/02571862.2021.1959660","url":null,"abstract":"We conducted on-farm trials in the southern Guinea savannah of Ghana in 2016 and 2017 to evaluate soyabean response to three fertiliser blends to guide farmers towards profitable adoption of appropriate phosphorus fertiliser blend for improved soyabean production. Old Yara Legume, New Yara Legume and Triple Superphosphate fertiliser blends were evaluated. In both years, the phosphorus fertiliser blends were evaluated in a Randomised Complete Block Design with 20, 30, and 40 kg P ha−1 application rates together with control. Phosphorus fertiliser application increased soyabean yields by 1 070 kg ha−1. In 2016, fertiliser blend use efficiency ranged from 2.9 kg grain per kg fertiliser blend applied with the New Yara Legume applied at 40 kg P ha−1 to 7.4 kg grain per kg fertiliser blend applied with the Triple Superphosphate applied at 40 kg P ha−1 with significant differences between treatments. In 2017, blend use efficiency ranged from 2.5 kg grain per kg fertiliser blend applied with Old Yara Legume applied at 40 kg P ha−1 to 9.2 kg grain per kg fertiliser blend applied with the Triple Superphosphate applied at 40 kg P ha−1 with significant differences between treatments. However, phosphorus use efficiency did not significantly differ between the different treatments both in the 2016 and 2017 trials. In both 2016 and 2017 trials, the highest benefit cost ratio was attained at the lowest application rate for all the three fertiliser blends suggesting the need to review the current application rate of 30 kg P fertiliser ha−1 promoted in northern Ghana. Furthermore, the provision of credit and/or subsidy for farmers by the government is required to enable uptake and utilisation of fertilisers by farmers.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41538630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.1080/02571862.2021.1938260
Bongo Mabusela, Z. A. Belay, B. Godongwana, N. Pathak, P. Mahajan, P. Mathabe, O. J. Caleb
The management of ethylene during postharvest storage is of critical importance to fresh produce wholesalers and retailers. The management of ethylene is an important determinant of the quality and shelf life of fresh fruit and vegetables. Ethylene blocking action and ethylene removal via potassium permanganate, photocatalytic oxidation and ozonation have been extensively researched and applied on a commercial scale to manage the impacts of ethylene postharvest. However, these techniques have certain inherent limitations that make them ineffective for long-term postharvest applications. This review therefore focuses on ethylene removal strategies during postharvest handling, and characterisation of the merits and demerits of such strategies. In addition, it provides an overview of emerging techniques such as photolysis, photocatalytic oxidation and ozone-assisted catalytic oxidation, as alternatives for ethylene management along the postharvest value chains. The intent of this review was to guide the development of more effective ethylene management technologies for long-term application in the South African fruit industry.
{"title":"Trends in ethylene management strategies: towards mitigating postharvest losses along the South African value chain of fresh produce – a review","authors":"Bongo Mabusela, Z. A. Belay, B. Godongwana, N. Pathak, P. Mahajan, P. Mathabe, O. J. Caleb","doi":"10.1080/02571862.2021.1938260","DOIUrl":"https://doi.org/10.1080/02571862.2021.1938260","url":null,"abstract":"The management of ethylene during postharvest storage is of critical importance to fresh produce wholesalers and retailers. The management of ethylene is an important determinant of the quality and shelf life of fresh fruit and vegetables. Ethylene blocking action and ethylene removal via potassium permanganate, photocatalytic oxidation and ozonation have been extensively researched and applied on a commercial scale to manage the impacts of ethylene postharvest. However, these techniques have certain inherent limitations that make them ineffective for long-term postharvest applications. This review therefore focuses on ethylene removal strategies during postharvest handling, and characterisation of the merits and demerits of such strategies. In addition, it provides an overview of emerging techniques such as photolysis, photocatalytic oxidation and ozone-assisted catalytic oxidation, as alternatives for ethylene management along the postharvest value chains. The intent of this review was to guide the development of more effective ethylene management technologies for long-term application in the South African fruit industry.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44689602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.1080/02571862.2021.1933630
K. Ravhuhali, V. Mlambo, T. S. Beyene, L. Palamuleni
The distribution and status of grass species is essential for sustainable management of rangelands. Therefore, this study assessed the spatial distribution and nutritive value of grass species as influenced by soil type in selected rangelands of the North West province of South Africa. Grass species were harvested from four communal areas (clay loam and red brown sand soil types) using three transects per study area. Each transect was sub-divided into near (0.5–0.7 km), middle (0.70–1.4 km) and far sub-transects (1.4–2.2 km) based on distance from homesteads. Within each sub-transect, 10 m × 10 m homogeneous vegetation units (HVU) were marked and quadrats (1 m2) were randomly placed within each HVU to sample soil and grasses. Species composition, abundance, biomass and nutritive value of grass species were measured. Only 21% of grasses identified in the study areas were determined to be of high grazing value. Aristida species were more common and dominant in both soil types. Eragrostis cylindriflora 2 Hochst. had higher crude protein content and the highest in vitro ruminal dry matter degradability after 24 and 48 hours. Thus, E. cylindriflora was the most valuable grass species for livestock farming in the study areas and could be earmarked for rangeland restoration.
{"title":"Effect of soil type on spatial distribution and nutritive value of grass species growing in selected rangelands of South Africa","authors":"K. Ravhuhali, V. Mlambo, T. S. Beyene, L. Palamuleni","doi":"10.1080/02571862.2021.1933630","DOIUrl":"https://doi.org/10.1080/02571862.2021.1933630","url":null,"abstract":"The distribution and status of grass species is essential for sustainable management of rangelands. Therefore, this study assessed the spatial distribution and nutritive value of grass species as influenced by soil type in selected rangelands of the North West province of South Africa. Grass species were harvested from four communal areas (clay loam and red brown sand soil types) using three transects per study area. Each transect was sub-divided into near (0.5–0.7 km), middle (0.70–1.4 km) and far sub-transects (1.4–2.2 km) based on distance from homesteads. Within each sub-transect, 10 m × 10 m homogeneous vegetation units (HVU) were marked and quadrats (1 m2) were randomly placed within each HVU to sample soil and grasses. Species composition, abundance, biomass and nutritive value of grass species were measured. Only 21% of grasses identified in the study areas were determined to be of high grazing value. Aristida species were more common and dominant in both soil types. Eragrostis cylindriflora 2 Hochst. had higher crude protein content and the highest in vitro ruminal dry matter degradability after 24 and 48 hours. Thus, E. cylindriflora was the most valuable grass species for livestock farming in the study areas and could be earmarked for rangeland restoration.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43644014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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