Pub Date : 2023-01-01DOI: 10.1080/02571862.2022.2137591
Alireza Eslami-Firouzabadi, M. Karimi, Ali Abbasi-surki, A. Shafeinia, Fatemeh Derikvand-Moghadam
Nitrogen (N) is the nutrient most used by crop producers and its application may affect the N use efficiency in crop production. The present study was conducted in order to determine the optimum N fertiliser rate and application stages (S) for stevia (Stevia rebaudiana Bertoni) production for the first cutting, under greenhouse conditions. A two-factorial experiment with four N fertiliser rates (0, 40, 80 and 120 kg ha−1 applied as urea) and three stages (sole split N applied at sowing; dual split N applied at sowing and one month after sowing; triple split N applied at sowing, one and two months from sowing) were laid out in a completely randomised design. Each treatment combination was replicated three times. The plants were grown in boxes (1 m−2, 40 cm high) filled with loam soil and the treatments were applied as described. Results showed that stevia growth and metabolites were significantly affected by N rates and application stages. Stevia leaf area index (LAI), leaf yield, leaf/stem ratio and harvest index (HI), steviol glycosides (SVglys) content, SVglys compositions and yield were the highest when 40 kg N ha−1 was applied in two stages. This was also true for leaf and SVglys yield. Splitting of N application of 120 kg ha−1 into three stages showed an inhibitory effect on some stevia traits such as SVglys content and yield. Based on the current results and efficient N application, 40 kg N ha−1 split into two stages is recommended for stevia production under greenhouse conditions.
氮是作物生产者使用最多的营养素，其施用可能会影响作物生产中的氮利用效率。本研究旨在确定在温室条件下，甜菊（甜叶菊）第一次扦插生产的最佳氮肥用量和施用阶段（S）。四种氮肥用量（0、40、80和120）的两因子试验 kg ha−1作为尿素施用）和三个阶段（播种时施用单裂氮；播种时和播种后一个月施用双裂氮；在播种时施用三裂氮，播种后一和两个月）以完全随机的设计进行布置。每个治疗组合重复三次。这些植物生长在盒子里（1 m−2，40 cm高），并按所述进行处理。结果表明，施氮量和施用阶段对甜菊的生长和代谢产物有显著影响。甜菊叶面积指数（LAI）、叶产量、叶茎比和收获指数（HI）、甜菊糖苷（SVglys）含量、SVglys成分和产量在40 kg N ha−1分两个阶段施用。叶片和SVglys产量也是如此。120的N应用程序的拆分 kg ha−1分为三个阶段对甜菊糖含量和产量等一些性状表现出抑制作用。根据目前的结果和有效的N应用，40 建议将kg N ha−1分为两个阶段用于温室条件下的甜菊生产。
{"title":"Optimising the rate and stages of application of nitrogen fertiliser for stevia under greenhouse conditions","authors":"Alireza Eslami-Firouzabadi, M. Karimi, Ali Abbasi-surki, A. Shafeinia, Fatemeh Derikvand-Moghadam","doi":"10.1080/02571862.2022.2137591","DOIUrl":"https://doi.org/10.1080/02571862.2022.2137591","url":null,"abstract":"Nitrogen (N) is the nutrient most used by crop producers and its application may affect the N use efficiency in crop production. The present study was conducted in order to determine the optimum N fertiliser rate and application stages (S) for stevia (Stevia rebaudiana Bertoni) production for the first cutting, under greenhouse conditions. A two-factorial experiment with four N fertiliser rates (0, 40, 80 and 120 kg ha−1 applied as urea) and three stages (sole split N applied at sowing; dual split N applied at sowing and one month after sowing; triple split N applied at sowing, one and two months from sowing) were laid out in a completely randomised design. Each treatment combination was replicated three times. The plants were grown in boxes (1 m−2, 40 cm high) filled with loam soil and the treatments were applied as described. Results showed that stevia growth and metabolites were significantly affected by N rates and application stages. Stevia leaf area index (LAI), leaf yield, leaf/stem ratio and harvest index (HI), steviol glycosides (SVglys) content, SVglys compositions and yield were the highest when 40 kg N ha−1 was applied in two stages. This was also true for leaf and SVglys yield. Splitting of N application of 120 kg ha−1 into three stages showed an inhibitory effect on some stevia traits such as SVglys content and yield. Based on the current results and efficient N application, 40 kg N ha−1 split into two stages is recommended for stevia production under greenhouse conditions.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42577430","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 : 2023-01-01DOI: 10.1080/02571862.2022.2148007
Marvellous M. Zhou
Cultivar genetic gains quantify the increase in productivity from release of cultivars and measure genetic improvements from plant breeding. The objectives of this study were to evaluate the genetic gains from sugarcane coastal cultivars and evaluate their contribution to productivity. Data were derived from replicated plant breeding and post-release variety evaluation trials conducted by the South Africa Sugarcane Research Institute (SASRI) from 1996 to 2020. There were significant cultivar differences for cane yield, sucrose content, sugar yield, fibre % and purity %. Significant analyses of cultivar by location, cultivar by crop-year and cultivar by location by crop-year indicate further optimisation of cultivar disposition is needed to increase productivity. Cultivar genetic gains were found for cane yield (0.19–0.48 t ha−1), sucrose content (0.01–0.02%), sugar yield (0.03–0.07 t ha−1 per year), fibre % cane (0.04–0.06%) and purity % (0.02–0.04%), highlighting the increased yield and quality from genetic improvement. The best cultivars produced 8–22% higher sugar yields than popular cultivars indicating that planting high yield cultivars did increase yields. Sugar cane production declined at a slower rate than area planted, also showing the benefit of high yield cultivars. Increasing the area planted to new, higher yielding cultivars will increase sugar yields for coastal regions of South Africa.
品种遗传增益量化了品种释放后生产力的提高，并衡量了植物育种的遗传改进。本研究的目的是评估沿海甘蔗品种的遗传增益，并评估其对生产力的贡献。数据来源于南非甘蔗研究所（SASRI）在1996年至2020年进行的复制植物育种和释放后品种评估试验。甘蔗产量、蔗糖含量、糖产量、纤维%和纯度%存在显著的品种差异。按地点、按作物年份和按作物年份对栽培品种进行的显著分析表明，需要进一步优化栽培品种配置，以提高生产力。甘蔗产量（0.19–0.48 t ha−1）、蔗糖含量（0.01–0.02%）、糖产量（0.03–0.07 t ha−每年）、甘蔗纤维%（0.04–0.06%）和纯度%（0.02–0.04%）的品种遗传增益突出了遗传改良带来的产量和质量提高。最佳品种的糖产量比流行品种高8-22%，表明种植高产品种确实提高了产量。甘蔗产量的下降速度低于种植面积，这也表明了高产品种的好处。增加种植面积，种植新的高产品种，将提高南非沿海地区的糖产量。
{"title":"Sugarcane cultivar genetic gains for coastal agro-ecological regions of South Africa","authors":"Marvellous M. Zhou","doi":"10.1080/02571862.2022.2148007","DOIUrl":"https://doi.org/10.1080/02571862.2022.2148007","url":null,"abstract":"Cultivar genetic gains quantify the increase in productivity from release of cultivars and measure genetic improvements from plant breeding. The objectives of this study were to evaluate the genetic gains from sugarcane coastal cultivars and evaluate their contribution to productivity. Data were derived from replicated plant breeding and post-release variety evaluation trials conducted by the South Africa Sugarcane Research Institute (SASRI) from 1996 to 2020. There were significant cultivar differences for cane yield, sucrose content, sugar yield, fibre % and purity %. Significant analyses of cultivar by location, cultivar by crop-year and cultivar by location by crop-year indicate further optimisation of cultivar disposition is needed to increase productivity. Cultivar genetic gains were found for cane yield (0.19–0.48 t ha−1), sucrose content (0.01–0.02%), sugar yield (0.03–0.07 t ha−1 per year), fibre % cane (0.04–0.06%) and purity % (0.02–0.04%), highlighting the increased yield and quality from genetic improvement. The best cultivars produced 8–22% higher sugar yields than popular cultivars indicating that planting high yield cultivars did increase yields. Sugar cane production declined at a slower rate than area planted, also showing the benefit of high yield cultivars. Increasing the area planted to new, higher yielding cultivars will increase sugar yields for coastal regions of South Africa.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49416879","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 : 2023-01-01DOI: 10.1080/02571862.2023.2185693
B. Coetzee, E. Carstens, G. C. Schutte, E. Basson, Mia J Groeneveld, Tankiso Mpholo, P. Moyo, Jessica C Winn, P. Fourie, A. V. D. van der Merwe
Phyllosticta citricarpa is the causative agent of citrus black spot (CBS), a cosmetic fungal disease that has been reported in most of the citrus-growing regions of the world. The occurrence of CBS in orchards is predominantly controlled by the application of fungicides during the fruit susceptibility period. Benzimidazoles (benomyl and carbendazim) and toluamides (ethaboxam and zoxamide) are two systemic fungicide classes suitable for the control of CBS in South Africa. Both inhibit proper assembly of the fungal β-tubulin protein during mitosis, and resistance to these fungicides is primarily related to alterations in the binding sites on this target protein. In this study, P. citricarpa isolates with known resistance status were subjected to whole genome sequencing, the mutations conferring resistance to benomyl and zoxamide were examined and allele-specific primers targeting these mutations were developed. The allele-specific multiplex PCR assay for the detection of benomyl resistance in P. citricarpa will eliminate the need for laborious and time-consuming sensitivity assays or DNA sequencing.
{"title":"An allele-specific PCR assay for detection of mutations that confer benzimidazole resistance and zoxamide sensitivity in Phyllosticta citricarpa","authors":"B. Coetzee, E. Carstens, G. C. Schutte, E. Basson, Mia J Groeneveld, Tankiso Mpholo, P. Moyo, Jessica C Winn, P. Fourie, A. V. D. van der Merwe","doi":"10.1080/02571862.2023.2185693","DOIUrl":"https://doi.org/10.1080/02571862.2023.2185693","url":null,"abstract":"Phyllosticta citricarpa is the causative agent of citrus black spot (CBS), a cosmetic fungal disease that has been reported in most of the citrus-growing regions of the world. The occurrence of CBS in orchards is predominantly controlled by the application of fungicides during the fruit susceptibility period. Benzimidazoles (benomyl and carbendazim) and toluamides (ethaboxam and zoxamide) are two systemic fungicide classes suitable for the control of CBS in South Africa. Both inhibit proper assembly of the fungal β-tubulin protein during mitosis, and resistance to these fungicides is primarily related to alterations in the binding sites on this target protein. In this study, P. citricarpa isolates with known resistance status were subjected to whole genome sequencing, the mutations conferring resistance to benomyl and zoxamide were examined and allele-specific primers targeting these mutations were developed. The allele-specific multiplex PCR assay for the detection of benomyl resistance in P. citricarpa will eliminate the need for laborious and time-consuming sensitivity assays or DNA sequencing.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46924886","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 : 2023-01-01DOI: 10.1080/02571862.2023.2180098
Kelebohile Rose Seboko, J. V. van Tol, E. Kotzé
Soil carbon (C) is an important component in quality assessments and efficient models are required to estimate C rapidly. Accurate C assessments are valuable in monitoring land-use changes. Fourier-transform mid-infrared (FT-MIR) spectroscopy has proved to be a powerful tool for assessing C. The potential of FT-MIR spectroscopy to estimate C was evaluated using the following techniques: (1) three algorithms [partial least squares (PLS)], principal component regression (PCR), and classical least squares (CLS); and (2) disaggregating the dataset into subgroups based on soil depth and texture. The C contents of samples collected in the Johannesburg Granite Dome were determined by dry combustion for comparison. The soils ranged considerably in C (0.123–2.650%), clay (2.80–41.20%), and silt content (8.56–23.75%). Using standard normal variant (SNV), Savitzky-Golay smoothing and PLS, the best-performing model was the horizons subgroup which provided values of root mean square error for prediction (RMSEP) between 0.079 and 0.095%, root mean square error for calibration (RMSEC) = 0.041 − 0.092, r 2 pre = 0.6174–0.8459, r 2 cal = 0.6599–0.9778, residual prediction variation (RPD) = 2.404–2.753, and ratio of performance to interquartile range (RPIQ) = 2.667–3.454. The pronounced accuracy of FT-MIR spectroscopy coupled with PLS, pre-processing techniques, and textural subgroups confirms the potential of infrared spectroscopy as an efficient tool for estimating C content. Future studies should investigate the combined effects of FT-MIR spectroscopy and subgroups grouped according to soil types and land-uses when predicting C.
土壤碳（C）是质量评估的重要组成部分，需要有效的模型来快速估计碳。准确的C评估在监测土地利用变化方面很有价值。傅立叶变换中红外光谱（FT-MIR）已被证明是评估C的强大工具。使用以下技术评估了FT-MIR光谱估计C的潜力：（1）三种算法[偏最小二乘（PLS）]、主成分回归（PCR）和经典最小二乘（CLS）；以及（2）根据土壤深度和质地将数据集分解为多个子组。通过干燃烧测定在约翰内斯堡花岗岩圆顶采集的样品的C含量以进行比较。土壤的C（0.123–2.650%）、粘土（2.80–41.20%）和含泥量（8.56–23.75%）变化很大。使用标准正态变量（SNV）、Savitzky Golay平滑和PLS，表现最好的模型是层位亚组，该亚组提供了0.079至0.095%的预测均方根误差（RMSEP）和校准均方根误差 = 0.041−0.092，r 2 pre = 0.6174–0.8459，r 2 cal = 0.6599–0.9778，残差预测方差（RPD） = 2.404–2.753，以及绩效与四分位间距的比率（RPIQ） = 2.667–3.454.FT-MIR光谱与PLS、预处理技术和结构亚组相结合的显著准确性证实了红外光谱作为估计碳含量的有效工具的潜力。未来的研究应该调查FT-MIR光谱和根据土壤类型和土地用途分组的亚组在预测C。
{"title":"Predicting soil carbon in granitic soils using Fourier-transform mid-infrared (FT-MIR) spectroscopy: the value of database disaggregation","authors":"Kelebohile Rose Seboko, J. V. van Tol, E. Kotzé","doi":"10.1080/02571862.2023.2180098","DOIUrl":"https://doi.org/10.1080/02571862.2023.2180098","url":null,"abstract":"Soil carbon (C) is an important component in quality assessments and efficient models are required to estimate C rapidly. Accurate C assessments are valuable in monitoring land-use changes. Fourier-transform mid-infrared (FT-MIR) spectroscopy has proved to be a powerful tool for assessing C. The potential of FT-MIR spectroscopy to estimate C was evaluated using the following techniques: (1) three algorithms [partial least squares (PLS)], principal component regression (PCR), and classical least squares (CLS); and (2) disaggregating the dataset into subgroups based on soil depth and texture. The C contents of samples collected in the Johannesburg Granite Dome were determined by dry combustion for comparison. The soils ranged considerably in C (0.123–2.650%), clay (2.80–41.20%), and silt content (8.56–23.75%). Using standard normal variant (SNV), Savitzky-Golay smoothing and PLS, the best-performing model was the horizons subgroup which provided values of root mean square error for prediction (RMSEP) between 0.079 and 0.095%, root mean square error for calibration (RMSEC) = 0.041 − 0.092, r 2 pre = 0.6174–0.8459, r 2 cal = 0.6599–0.9778, residual prediction variation (RPD) = 2.404–2.753, and ratio of performance to interquartile range (RPIQ) = 2.667–3.454. The pronounced accuracy of FT-MIR spectroscopy coupled with PLS, pre-processing techniques, and textural subgroups confirms the potential of infrared spectroscopy as an efficient tool for estimating C content. Future studies should investigate the combined effects of FT-MIR spectroscopy and subgroups grouped according to soil types and land-uses when predicting C.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42145230","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 : 2023-01-01DOI: 10.1080/02571862.2022.2144959
R. Gericke, Njj Combrink, M. van der Rijst
Potatoes are an important crop in the Sandveld and Kouebokkeveld regions of South Africa, and one of the challenges in effective potato production is maintaining quality post-harvest. In order to identify tuber characteristics that may be used to predict keeping quality of potatoes from the sandy soils of these regions, tuber, soil, and water samples were taken from different growers who planted the cultivar Sifra. Sampling started in January 2016 and ended in July 2017. Skinning potential, determined by thumb rubbing, chemical composition, and specific gravity (SG) were evaluated one day after hand harvesting. Undamaged tubers were kept at room temperature for 42 days whereafter mass loss and firmness were evaluated. Pearson correlations and Partial Least Squares Regression (PLS-R) were done to investigate the association between tuber quality characteristics and tuber, soil and water cations. Tuber firmness after storage showed a high positive correlation with tuber magnesium (Mg) levels, and was associated with reduced skinning potentials and lower mass loss percentages. Tubers with Mg levels lower than 0.13% had high skinning potentials with mass loss percentages higher than 4.5% during storage. Irrigation with water rich in sodium (Na) tended to limit mass loss, possibly due to the associated high levels of Mg in those water sources.
{"title":"Low magnesium content in potato tubers associated with mass loss during storage","authors":"R. Gericke, Njj Combrink, M. van der Rijst","doi":"10.1080/02571862.2022.2144959","DOIUrl":"https://doi.org/10.1080/02571862.2022.2144959","url":null,"abstract":"Potatoes are an important crop in the Sandveld and Kouebokkeveld regions of South Africa, and one of the challenges in effective potato production is maintaining quality post-harvest. In order to identify tuber characteristics that may be used to predict keeping quality of potatoes from the sandy soils of these regions, tuber, soil, and water samples were taken from different growers who planted the cultivar Sifra. Sampling started in January 2016 and ended in July 2017. Skinning potential, determined by thumb rubbing, chemical composition, and specific gravity (SG) were evaluated one day after hand harvesting. Undamaged tubers were kept at room temperature for 42 days whereafter mass loss and firmness were evaluated. Pearson correlations and Partial Least Squares Regression (PLS-R) were done to investigate the association between tuber quality characteristics and tuber, soil and water cations. Tuber firmness after storage showed a high positive correlation with tuber magnesium (Mg) levels, and was associated with reduced skinning potentials and lower mass loss percentages. Tubers with Mg levels lower than 0.13% had high skinning potentials with mass loss percentages higher than 4.5% during storage. Irrigation with water rich in sodium (Na) tended to limit mass loss, possibly due to the associated high levels of Mg in those water sources.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48722659","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 : 2023-01-01DOI: 10.1080/02571862.2023.2192528
T. Baloyi, F. Kutu, C. du Preez
Large areas of soils in sub-Saharan Africa are poor in organic matter and nitrogen-phosphorus-potassium (NPK) fertilisation is essential for cropping. Most farmers are smallholders who cannot afford NPK fertilisers but they could consider alternatives like commercial organic ameliorants.This applies also for commercial farmers to improve profitability. The effects of nine ameliorants on the grain yield, biomass yield and harvest index of maize were evaluated over three years at Bothaville (8% clay), Ottosdal (12% clay) and Potchefstroom (34% clay). All ameliorants were applied as manufacturers prescribe. None of the ameliorants can serve as replacement of NPK fertilisers. Active ingredients other than the small amounts of N, P and K they contain, comprised of effective microorganisms (EMs), human manure, humic acids and poultry manure, and were not able to boost crop growth as manufacturers advocated. Biozone (EMs), Gliogrow (EMs), Growmax (Human manure), K-humate (Humic acid) and Crop Care (Humic acid) that were applied with NPK fertilisation resulted in 22 to 44% instances in significantly higher grain yield (938 to 1 288 kg ha−1) compared to the NPK control; however, many inconsistencies between experimental sites and years were observed. The use of commercial organic ameliorants cannot recommended to farmers without proper evaluation.
撒哈拉以南非洲的大片土壤缺乏有机质，氮、磷、钾(NPK)施肥对种植至关重要。大多数农民都是小农，负担不起氮磷钾肥料，但他们可以考虑商业有机改良剂等替代品。这也适用于商业农民提高盈利能力。以Bothaville(8%粘土)、Ottosdal(12%粘土)和Potchefstroom(34%粘土)为试验基地，评价了9种改良剂对玉米籽粒产量、生物量产量和收获指数的影响。所有改良剂均按制造商规定使用。这些改良剂都不能代替氮磷钾肥料。除了含有少量的氮、磷和钾外，它们还含有有效微生物(EMs)、人类粪便、腐植酸和家禽粪便等有效成分，并不能像制造商所倡导的那样促进作物生长。与氮磷钾对照相比，施用Biozone (EMs)、Gliogrow (EMs)、Growmax(人粪肥)、K-humate(腐植酸)和Crop Care(腐植酸)的氮磷钾组的产量显著提高了22%至44%(938至1 288 kg ha - 1);然而，在实验地点和年份之间观察到许多不一致。未经适当的评估，不能向农民推荐商业有机改良剂的使用。
{"title":"Is the use of commercial organic ameliorants for cropping justified?","authors":"T. Baloyi, F. Kutu, C. du Preez","doi":"10.1080/02571862.2023.2192528","DOIUrl":"https://doi.org/10.1080/02571862.2023.2192528","url":null,"abstract":"Large areas of soils in sub-Saharan Africa are poor in organic matter and nitrogen-phosphorus-potassium (NPK) fertilisation is essential for cropping. Most farmers are smallholders who cannot afford NPK fertilisers but they could consider alternatives like commercial organic ameliorants.This applies also for commercial farmers to improve profitability. The effects of nine ameliorants on the grain yield, biomass yield and harvest index of maize were evaluated over three years at Bothaville (8% clay), Ottosdal (12% clay) and Potchefstroom (34% clay). All ameliorants were applied as manufacturers prescribe. None of the ameliorants can serve as replacement of NPK fertilisers. Active ingredients other than the small amounts of N, P and K they contain, comprised of effective microorganisms (EMs), human manure, humic acids and poultry manure, and were not able to boost crop growth as manufacturers advocated. Biozone (EMs), Gliogrow (EMs), Growmax (Human manure), K-humate (Humic acid) and Crop Care (Humic acid) that were applied with NPK fertilisation resulted in 22 to 44% instances in significantly higher grain yield (938 to 1 288 kg ha−1) compared to the NPK control; however, many inconsistencies between experimental sites and years were observed. The use of commercial organic ameliorants cannot recommended to farmers without proper evaluation.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45663636","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 : 2022-10-20DOI: 10.1080/02571862.2022.2137590
H. van Zyl, C. du Preez
The sustainable production of wheat can be affected by soil acidity in the eastern Free State, South Africa. Liming of soil to appropriate acidity levels is therefore regarded as an essential farming practice. In some instances, however, planting of acid-tolerant wheat cultivars is recommended as an interim management measure. Hence, we evaluated the response (grain yield, grain protein content and hectoliter mass) of wheat cultivars with poor (Karee or Limpopo), moderate (SST 224 or Gariep) and good (Tugela DN) acid tolerance on soils (8–33% clay) over a range of lime-induced pH (KCl) values (3.7–5.7) under field conditions spanning 4 to 5 years. In Year 2 no data was collected due to staff shortages. Across the pH ranges, grain yields of the most acid-tolerant cultivars exceeded those of the moderately acid-tolerant cultivars by 29–54%, and those of the poorly acid-tolerant cultivars by 36–62%. Due to climatic conditions, larger differences in grain protein content were observed between years rather than between treatment combinations. Hectoliter mass, although influenced by treatment combinations, exceeded the threshold value of 76 kg hL−1. The results, especially of grain yield, proved the usefulness of acid-tolerant wheat cultivars during the initial stages of liming programs, until acceptable levels of soil acidity are reached.
南非自由邦东部的土壤酸度可能会影响小麦的可持续生产。因此，将土壤石灰化至适当的酸度水平被认为是一种必要的耕作方法。但在某些情况下，建议种植耐酸小麦品种作为临时管理措施。因此，我们在4 ~ 5年的田间条件下，对土壤(粘土含量为8-33%)耐酸性较差(Karee或Limpopo)、中等(SST 224或Gariep)和良好(Tugela DN)耐酸小麦品种在石灰诱导pH (KCl)值(3.7 ~ 5.7)范围内的响应(籽粒产量、籽粒蛋白质含量和千吨质量)进行了评价。在第二年，由于人员短缺，没有收集数据。在不同的pH值范围内，最耐酸品种的产量比中等耐酸品种高29-54%，较不耐酸品种的产量比中等耐酸品种高36-62%。由于气候条件的原因，籽粒蛋白质含量在不同年份之间的差异大于不同处理组合之间的差异。百升质量虽然受到处理组合的影响，但仍超过了76 kg hL−1的阈值。结果，特别是粮食产量，证明了耐酸小麦品种在石灰计划的初始阶段是有用的，直到土壤酸度达到可接受的水平。
{"title":"Response of wheat cultivars with varying acid tolerances to liming of eastern Free State soils","authors":"H. van Zyl, C. du Preez","doi":"10.1080/02571862.2022.2137590","DOIUrl":"https://doi.org/10.1080/02571862.2022.2137590","url":null,"abstract":"The sustainable production of wheat can be affected by soil acidity in the eastern Free State, South Africa. Liming of soil to appropriate acidity levels is therefore regarded as an essential farming practice. In some instances, however, planting of acid-tolerant wheat cultivars is recommended as an interim management measure. Hence, we evaluated the response (grain yield, grain protein content and hectoliter mass) of wheat cultivars with poor (Karee or Limpopo), moderate (SST 224 or Gariep) and good (Tugela DN) acid tolerance on soils (8–33% clay) over a range of lime-induced pH (KCl) values (3.7–5.7) under field conditions spanning 4 to 5 years. In Year 2 no data was collected due to staff shortages. Across the pH ranges, grain yields of the most acid-tolerant cultivars exceeded those of the moderately acid-tolerant cultivars by 29–54%, and those of the poorly acid-tolerant cultivars by 36–62%. Due to climatic conditions, larger differences in grain protein content were observed between years rather than between treatment combinations. Hectoliter mass, although influenced by treatment combinations, exceeded the threshold value of 76 kg hL−1. The results, especially of grain yield, proved the usefulness of acid-tolerant wheat cultivars during the initial stages of liming programs, until acceptable levels of soil acidity are reached.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48651001","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 : 2022-10-20DOI: 10.1080/02571862.2022.2119291
E. Ebrahimi, J. Zinkernagel
The northern part of Namibia suffers from drought and low-quality soil. The soil needs a boost of nutrients, and the water must be used in a frugal manner. Thereby, the objective of this research was to investigate the effect of sludge and treated wastewater as initial nutrient drivers in sandy loam soil by examining the dry biomass (DM), the nutrient uptake, and the heavy metal accumulation in the organs of sorghum. For this reason, sludge, chemical fertiliser, and a mixture of both were applied to a sorghum field. As a second factor, water of two different qualities was used: (a) treated wastewater (TWW), and (b) tap water. The treatment with mixed-fertiliser produced 16% more DM compared to the treatment with chemical fertiliser when irrigated with tap water. The use of TWW enhanced phosphorus uptake in the treatment with chemical fertiliser but did not increase the DM. This study suggests that sludge can be applied as an initial nutrient driver for poor soil with low organic matter and that TWW can also be an important complementary water resource for irrigation in areas affected by drought.
{"title":"Sludge as an initial nutrient driver for yield improvement in the poor soils of northern Namibia","authors":"E. Ebrahimi, J. Zinkernagel","doi":"10.1080/02571862.2022.2119291","DOIUrl":"https://doi.org/10.1080/02571862.2022.2119291","url":null,"abstract":"The northern part of Namibia suffers from drought and low-quality soil. The soil needs a boost of nutrients, and the water must be used in a frugal manner. Thereby, the objective of this research was to investigate the effect of sludge and treated wastewater as initial nutrient drivers in sandy loam soil by examining the dry biomass (DM), the nutrient uptake, and the heavy metal accumulation in the organs of sorghum. For this reason, sludge, chemical fertiliser, and a mixture of both were applied to a sorghum field. As a second factor, water of two different qualities was used: (a) treated wastewater (TWW), and (b) tap water. The treatment with mixed-fertiliser produced 16% more DM compared to the treatment with chemical fertiliser when irrigated with tap water. The use of TWW enhanced phosphorus uptake in the treatment with chemical fertiliser but did not increase the DM. This study suggests that sludge can be applied as an initial nutrient driver for poor soil with low organic matter and that TWW can also be an important complementary water resource for irrigation in areas affected by drought.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41948438","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 : 2022-10-20DOI: 10.1080/02571862.2022.2131009
Víctor Mondragón, F. Hurtado, Daniel Francisco Jaramillo Jaramillo
Soil organic carbon (SOC) is the main element in soil organic matter (SOM) and its storage or release into the atmosphere is sensitive to changes in land use. This study evaluated SOC storage and SOM quality in the Metropolitan Regional Natural Park, Cerro El Volador, MedelIín-Colombia, in areas where plant cover was restored with plants from different functional groups consisting of secondary vegetation (SV), forest plantations of Eucalyptus globulus Labill. (EUC) and Pinus patula Schltdl. & Cham. (PIN), and pastures (PAS). Soil samples were taken at the O horizon and at two soil depths at the A horizon (0–10 and 10–20 cm). The quality of the SOM was evaluated through humification indices, spectrophotometric tests and carbon distribution in humic substances. The highest storage of SOC in the O horizon occurred in PIN, followed by EUC, SV and PAS. In descending order, the vegetation with the highest SOC values for the A horizon at both depths evaluated were EUC, PAS, PIN and SV. Humification indices showed that the SOM was mainly composed of fresh SOM with little humification. The humification process of SOM evolved towards humic acids of the P-group. These results show that the change of cover significantly affects the storage of SOC, the characteristics of SOM and the properties of the soil.
土壤有机碳（SOC）是土壤有机质（SOM）中的主要元素，其储存或释放到大气中对土地利用的变化很敏感。本研究评估了哥伦比亚MedelIín-Colombia Cerro El Volador大都会区域自然公园的SOC储量和SOM质量，这些地区的植物覆盖被不同功能组的植物恢复，包括次生植被（SV）、蓝桉人工林。（EUC）和松Cham。（PIN）和牧场（PAS）。在O层和A层的两个土壤深度（0–10和10–20 cm）。通过腐殖化指数、分光光度法和腐殖物质中碳的分布来评价SOM的质量。SOC在O水平中的最高存储出现在PIN中，其次是EUC、SV和PAS。按降序排列，在两个深度评估的A层SOC值最高的植被是EUC、PAS、PIN和SV。腐殖化指数表明，SOM主要由新鲜SOM组成，腐殖化程度很低。SOM的腐殖化过程向P族腐殖酸演化。这些结果表明，覆盖的变化对土壤有机碳的储存、有机碳的特性和土壤性质有显著影响。
{"title":"Soil organic carbon stocks and properties are affected by plant cover types in an urban ecosystem in Colombia","authors":"Víctor Mondragón, F. Hurtado, Daniel Francisco Jaramillo Jaramillo","doi":"10.1080/02571862.2022.2131009","DOIUrl":"https://doi.org/10.1080/02571862.2022.2131009","url":null,"abstract":"Soil organic carbon (SOC) is the main element in soil organic matter (SOM) and its storage or release into the atmosphere is sensitive to changes in land use. This study evaluated SOC storage and SOM quality in the Metropolitan Regional Natural Park, Cerro El Volador, MedelIín-Colombia, in areas where plant cover was restored with plants from different functional groups consisting of secondary vegetation (SV), forest plantations of Eucalyptus globulus Labill. (EUC) and Pinus patula Schltdl. & Cham. (PIN), and pastures (PAS). Soil samples were taken at the O horizon and at two soil depths at the A horizon (0–10 and 10–20 cm). The quality of the SOM was evaluated through humification indices, spectrophotometric tests and carbon distribution in humic substances. The highest storage of SOC in the O horizon occurred in PIN, followed by EUC, SV and PAS. In descending order, the vegetation with the highest SOC values for the A horizon at both depths evaluated were EUC, PAS, PIN and SV. Humification indices showed that the SOM was mainly composed of fresh SOM with little humification. The humification process of SOM evolved towards humic acids of the P-group. These results show that the change of cover significantly affects the storage of SOC, the characteristics of SOM and the properties of the soil.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43628272","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 : 2022-10-20DOI: 10.1080/02571862.2022.2142972
Hanine Loucif, B. Bousalhih, Rebiha Chaoui, J. Drevon, M. Farissi, M. Lazali
Low phosphorus (P) availability is a major constraint for chickpea production. Consequently, P-efficient genotypes can improve productivity under conditions where the higher application of P is not economical. This study was conducted to characterise four chickpea genotypes for nutrient uptake and use efficiency under low-P conditions over two growing seasons. At flowering stage, plants were harvested and analysed for their nodulation, growth, P content and yield. Results indicate that low P availability significantly limited plant growth, nodulation and yield for all genotypes with the greatest effect on for Flip 84-92C and Flip 01-29C. The genotypes Flip 90-13C and ILC 32-79 showed the highest P uptake and use efficiency. The genotypes with high nutrient uptake had better efficiency in use of rhizobial symbiosis. It is concluded that nutrient uptake and use efficiency may be an important functional trait that may contribute to the selection of cultivars able to produce high quality seeds and efficiently fix nitrogen under conditions of low soil P.
{"title":"Genotypic variability in nutrient uptake and use efficiency in chickpea grown under low phosphorus availability in a Mediterranean climate","authors":"Hanine Loucif, B. Bousalhih, Rebiha Chaoui, J. Drevon, M. Farissi, M. Lazali","doi":"10.1080/02571862.2022.2142972","DOIUrl":"https://doi.org/10.1080/02571862.2022.2142972","url":null,"abstract":"Low phosphorus (P) availability is a major constraint for chickpea production. Consequently, P-efficient genotypes can improve productivity under conditions where the higher application of P is not economical. This study was conducted to characterise four chickpea genotypes for nutrient uptake and use efficiency under low-P conditions over two growing seasons. At flowering stage, plants were harvested and analysed for their nodulation, growth, P content and yield. Results indicate that low P availability significantly limited plant growth, nodulation and yield for all genotypes with the greatest effect on for Flip 84-92C and Flip 01-29C. The genotypes Flip 90-13C and ILC 32-79 showed the highest P uptake and use efficiency. The genotypes with high nutrient uptake had better efficiency in use of rhizobial symbiosis. It is concluded that nutrient uptake and use efficiency may be an important functional trait that may contribute to the selection of cultivars able to produce high quality seeds and efficiently fix nitrogen under conditions of low soil P.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49468975","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：