Botswana Journal of Agriculture and Applied Sciences最新文献_第2页

The potential for heavy metal pollution in crops from urban and peri urban horticultural farms in the Gaborone environs: a review 哈博罗内周边城市和城郊园艺农场作物重金属污染的可能性:综述

Botswana Journal of Agriculture and Applied Sciences Pub Date : 2019-03-12 DOI: 10.37106/bojaas.2019.10

L. C. Obuseng

{"title":"The potential for heavy metal pollution in crops from urban and peri urban horticultural farms in the Gaborone environs: a review","authors":"L. C. Obuseng","doi":"10.37106/bojaas.2019.10","DOIUrl":"https://doi.org/10.37106/bojaas.2019.10","url":null,"abstract":"The introduction of urban and peri-urban agriculture (UPA) is usually characterized by high input intensity. This intensive use of chemical fertilizers, pesticides, wastewater, sludges and industrial effluents may lead to accumulation of potentially toxic metals in the soil, increasing the geological background levels and exceeding the capacity to immobilize them. Besides being environmental pollutants of which the toxicity is a problem of increasing significance for ecological reasons, heavy metal accumulation in the food chain is highly dangerous for human health. The objective of this review was to highlight the potential problems that may arise as a consequence of irrigating crops with sewage water as well as using fertilizers and pesticides. A review of literature has shown that different types of fertilizers contain some quantities of heavy metals that may buildup in the soil as well as be taken up by crops. In addition to using fertilizers, the use of treated and sometimes partially treated and untreated water by UPA farmers around Gaborone may lead to heavy metal accumulation in soil as well as in crops, posing a danger to human beings. In Botswana there is limited information concerning heavy metal accumulation in soils even though there is a high use of agrochemicals in vegetable production in UPA land use systems. Lack of such information necessitates research on the impact of the application of fertilizer, sewage water (treated and untreated) and metal-based pesticides on the quality of the vegetable produce coming from UPA.","PeriodicalId":147981,"journal":{"name":"Botswana Journal of Agriculture and Applied Sciences","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121055604","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}

引用次数: 1

Evaluation of Bradyrhizobium formulations on performance of soybean grown on soil without a long-term history of the crop 缓生根瘤菌制剂对大豆在没有长期作物历史的土壤上生长的性能的评价

Botswana Journal of Agriculture and Applied Sciences Pub Date : 2019-03-12 DOI: 10.37106/bojaas.2019.9

J. Adjetey

{"title":"Evaluation of Bradyrhizobium formulations on performance of soybean grown on soil without a long-term history of the crop","authors":"J. Adjetey","doi":"10.37106/bojaas.2019.9","DOIUrl":"https://doi.org/10.37106/bojaas.2019.9","url":null,"abstract":"Farmers have raised concerns about the inability of some commercial soybean inoculants to elicit effective nodulation. Nodulation failure has been attributed to, among others, high temperatures, soil acidity and type of inoculant used. This work examined the influence of two Bradyrhizobium japonicum inoculant formulations on soybean grown on soil without a soybean cropping history for about eight years. The experiment was conducted in a controlled environment facility at the University of KwaZulu-Natal. The treatments were two levels of a liquid formulation of the Bradyrhizobium WB 74 initially consisting of 2.6×109 colony forming units ml-1 and one level of a powder formulation containing a minimum of 6.5×108 live cells g-1. The results showed that applying the two formulations of B. japonicum to seed, enhanced soybean nodule number, leaf number, nutrient concentration and uptake compared to the control treatment, and both powder and liquid formulations enhanced yield components to the same extent. Although the low concentration of the liquid formulation was less effective in increasing nodule number, other responses it elicited were comparable to the high concentration of the liquid and powder formulations. We conclude that small differences may exist between commonly available commercial inoculants of Bradyrhizobium WB 74 but they are effective in promoting nodulation and growth of soybean, and that reported major nodulation failures may be attributed to management factors other than inoculant formulation per se.","PeriodicalId":147981,"journal":{"name":"Botswana Journal of Agriculture and Applied Sciences","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117218369","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}

引用次数: 6

Lime and foliar application of molybdenum affects nodulation, nutrient uptake and pod production in soybean grown in acid soils 石灰和叶面施钼对酸性土壤中大豆结瘤、养分吸收和荚果产量有影响

Botswana Journal of Agriculture and Applied Sciences Pub Date : 2019-03-12 DOI: 10.37106/bojaas.2019.8

J. Adjetey

{"title":"Lime and foliar application of molybdenum affects nodulation, nutrient uptake and pod production in soybean grown in acid soils","authors":"J. Adjetey","doi":"10.37106/bojaas.2019.8","DOIUrl":"https://doi.org/10.37106/bojaas.2019.8","url":null,"abstract":"Soil acidity is commonly ameliorated with lime while little attention is given to the application of molybdenum which is deficient in acid soils. Molybdenum is an important component of the nitrogenase enzyme essential for the symbiotic nitrogen fixing bacteria. An experiment was conducted in a controlled environment at the University of KwaZulu-Natal to evaluate the effect of lime and molybdenum on nodulation, growth and shoot nutrient content of soybean. The experiment was a randomised complete block design with three rates of lime applied at 0, 2650 and 4280 kg ha-1 and molybdenum as ammonium molybdate at 0 and 0.5 g L-1. Lime significantly (p<0.01) increased the uptake of Ca and P but decreased that of Mn. Also, increasing lime levels positively influenced most of the important plant growth parameters measured in the study. Molybdenum application significantly increased nodule formation but did not influence the concentration and uptake of the nutrients measured. Lime application also improved soil Ca and Mg but reduced Mn and exchangeable acidity levels at the end of the study. The treatment combination of lime at 4280 kg ha-1 and ammonium molybdate at 0.5 g L-1 gave the best result in nearly all parameters tested and it can hence be concluded that this combination improves both the nutrient uptake and nodulation of soybean grown in soil with very high acid saturation.","PeriodicalId":147981,"journal":{"name":"Botswana Journal of Agriculture and Applied Sciences","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133862527","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}

引用次数: 2

Selected Papers Presented at the 17th Biennial Conference of the African Association for Biological Nitrogen Fixation held between 17th and 21st October 2016 in Gaborone, Botswana 2016年10月17日至21日在博茨瓦纳哈博罗内举行的第17届非洲生物固氮协会双年会议上发表的论文精选

Botswana Journal of Agriculture and Applied Sciences Pub Date : 2019-03-11 DOI: 10.37106/BOJAAS.2019.1

Flora Pule-Meulenberg

引用次数: 0

Phytochemical constituents in edible parts of anchote (Coccinia abyssinica (lam.) (cogn.)) accessions from Ethiopia 埃塞俄比亚凤尾鱼(Coccinia abyssinica (lam.) (con .))可食用部分的植物化学成分

Botswana Journal of Agriculture and Applied Sciences Pub Date : 2019-03-11 DOI: 10.37106/bojaas.2019.2

G. Haki

{"title":"Phytochemical constituents in edible parts of anchote (Coccinia abyssinica (lam.) (cogn.)) accessions from Ethiopia","authors":"G. Haki","doi":"10.37106/bojaas.2019.2","DOIUrl":"https://doi.org/10.37106/bojaas.2019.2","url":null,"abstract":"Anchote (Coccinia abyssinica) accessions from Ethiopia were tested for the presence of major phytochemicals using qualitative and quantitative methods. The qualitative tests were performed for 12 phytochemical compounds with 6 solvent extracts and water using standard methods. Quantitative analysis for important secondary metabolites included total phenols, total flavonoids, crude saponins and beta-carotene. Of the 12 phytochemicals tested, five compounds showed positive results for all the seven extracts in the tubers, whereas only two phytochemicals responded positively in the leaves. The water extract of anchote showed positive results for 11 of the phytochemicals while n-butanol showed positive results for six in both the tuber and leaf parts. The water extract also had the highest phytochemicals in both the tuber and leaf parts when compared to the other solvent extracts. Anchote leaf had the highest total phenol and flavonoid contents followed by the fruit and the least concentration was in the tuber for all the accessions. The leaf contained the highest percentage of saponins (27.65%) while tuber had the lowest (14.65%). The β-carotene content in five accessions of anchote leaf ranged from 25.9±0.03 to 35.2±0.16 µg/g. Anchote is popular in the Oromo and non-Oromo tribes in Ethiopia, because of its medicinal role. Owing to the various phytochemical compounds present in the plant further screening and identification of its active compounds is recommended.","PeriodicalId":147981,"journal":{"name":"Botswana Journal of Agriculture and Applied Sciences","volume":"362 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130960049","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}

引用次数: 1