African Journal of Soil Science

African Journal of Soil Science ISSN 2375-088X Vol. 11 (9), pp. 001-009, September, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Impact of Biochar Application on Waterleaf (Talinum triangulare) Growth in Humid-Tropical Forest Soil

Billa Samuel Fru¹*, Ngome Ajebesone Francis², Tsi Evaristus Angwafo³ and Tata Ngome Precillia²

¹School of Agriculture and Environment, University of Dschang, P.O. Box 222, Dschang, Cameroon.
²Institute of Agricultural Research for Development, P.O. Box 2123 Yaoundé, Cameroon.
³Department of Fundamental Science, University of Bamenda, P.O. Box 39 Bambilli, Cameroon.

Accepted 20 July, 2024

Abstract

Waterleaf (Talinum triangulare), like many other leafy vegetable is cultivated in home gardens to improve nutritional quality for the family and may provide additional income for female farmers. However, the role of Talinum cultivation is often counteracted by declining soil fertility. In recent years, biochar (pyrolysed biomass) has gained importance as a soil amendment tool. However, not much attention has been focused on the influence of biochar on soil quality and plant growth in the humid tropics. This study was conducted to assess different locally available crop waste residues as possible sources of biochar for home garden or small-scale production units of leafy vegetable using Talinum as proxy on highly weathered acid soils in the humid tropics. The experimental set-up was a pot experiment in a complete randomized design in five replicates using biochar sources from cassava stems, rice husk, corncob and sawdust. The results obtained showed that biochar samples had a high cation exchange capacity (CEC), total nitrogen, total carbon and pH (7.8 to 10.8), as compared to the no-input soil (pH 5.7). It is evident that adding biochar to poor and acidic soils could possibly increase the pH and reduce lime requirements. Positive and significant response of biochar (P<0.05) application were also observed with the growth, nutrient uptake, and yield of waterleaf. Biochar produced from rice husks obtained the best response followed by sawdust, cassava and corncob. Similarly, the C and N uptake of waterleaf was generally higher with rice husk biochar use as compared to the other treatments. This study has demonstrated that biochar production could be useful in valorizing crop waste residues and biochar use is likely to enhance the productivity of leafy vegetables. More research on possible combination of biochar and other farming strategies such as the application of animal manure and mineral fertilizer to maximize Talinum production should be encouraged.

Key words: Biochar, cassava stems, crop waste, residues, nitrogen, soil pH, Talinum.
 

African Journal of Soil Science ISSN 2375-088X Vol. 11 (9), pp. 001-012, September, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Investigating phosphorus fixation in relation to soil physicochemical properties on the eastern side of Mount Cameroon

Kenneth Mbene^1,2*, Aaron SuhTening³, Cheo Emmanuel Suh⁴, Norbert Nkafu Fomenky² and Vivian Bih Che⁴

¹Department of Chemistry, Higher Teacher Training College, University of Yaounde 1, P. O. Box 47, Yaounde,
Cameroon.
²Department of Chemistry, University of Buea, P. O. Box 63, Buea, Cameroon.
³Department of Agronomic and Applied Molecular Sciences, University of Buea, P. O. Box 63, Buea, Cameroon.
⁴Department of Geology, University of Buea, P.O. Box 63, Buea, Cameroon.

Accepted 4 July, 2024

Abstract

The Eastern flank of Mount Cameroon is made up of human settlement and agricultural activities. Determination of phosphorus (P) fixation characteristics of soils around this region is important for a clean environment and economic fertilizer application. The objectives of this study were to evaluate P-fixation characteristics of soils within the region and identify factors contributing to P-fixation. Composite surface soil samples from five sites (between 36 to 1006 m) were collected and analyzed for physicochemical properties and P-fixation capacity. Fixation data were obtained by equilibrating the five soil samples with 25 ml of KH2PO4 in 0.01 M CaCl2, containing 0, 10, 50, 100, 250 and 500 mg L-1. Phosphorus-fixation data were fitted to Langmuir and Freundlich adsorption models and the relationship between P-fixation and soil properties was determined. The adsorption maximum (KL) for Freundlich model was the highest for Limbe - Man O’War Bay Road (LMR, 174.58 mg P kg-1), followed by SLR (34.12 mg P kg-1), Dibanda-Mutengene Road (DMR, 24.72 mg P kg-1), VAS and UPD (16.87 mg P kg-1). The Langmuir adsorption maximum for Vasingi (VAS), Upper Boduma (UPD), Sasse-Limbe Road (SLR), DMR, and LMR were 0.01, 0.02, 0.01, 0.02 and 0.05 mg P kg-1, respectively. The phosphate adsorption isotherm gave good fit adopting Freundlich (r = 0.98 to 0.99). KF correlated with pH (r = - 0.87), Ca (r = - 0.87), exchange acidity (r = 0.87), and clay (r = 0.67). This study illustrated that P sorption isotherm in relation to soil properties can be used as a tool for P management in sustainable crop production.

Key words: Phosphorus fixation, adsorption isotherms, soil physicochemical properties, volcanic soils, Mount Cameroon.

African Journal of Soil Science ISSN 2375-088X Vol. 11 (9), pp. 001-013, September, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Review

Analysis of heavy metals in soil and water systems of urban and semi-urban areas in Malawi: Insights from comparative research with other nations

Chikumbusko Chiziwa Kaonga¹*, Ishmael BobbyMphangwe Kosamu¹, Deliwe Dinah Lakudzala¹, Rex Mbewe1, Benard Thole¹, Morris Monjerezi², Russel Chrispine Garvin Chidya^3,4, Stephen Kuyeli⁵ and Samson Mkali Idruss Sajidu²

¹Physics and Biochemical Sciences Department, University of Malawi, The Polytechnic, P/Bag 303, Chichiri,
Blantyre 3, Malawi.
²Chemistry Department, Chancellor College, P. O. Box 280, Zomba, Malawi.
³Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan.
⁴Faculty of Environmental Sciences, Mzuzu University, P/Bag 201, Mzuzu, Malawi.

⁵Malawi Bureau of Standards, P. O. Box 946, Blantyre, Malawi.

Received 13 June, 2024; Accepted 26 July, 2024 and Published 10 September, 2024

Abstract

Growth of cities in developing countries comes with increasing transportation and industrial activities which may contribute to accumulation of heavy metals in the environment. This paper provides a review of studies on heavy metals in Malawi`s environment, their potential environmental impacts and possible removal methods with comparisons to other selected countries. The reviewed data from Malawi showed that in water samples, heavy metal concentrations were higher than World Health Organisation (WHO) and Malawi Bureau of Standards (MBS) safe limits especially in streams passing through industrial sites. Reports of heavy metals (especially Cu, Mn and Zn) showed that in industrial effluents, the individual levels of each of them were at least 6 times higher as compared to those in surface water bodies. In rivers there was accumulation of heavy metals (Cu, Cd, Cr, Fe, Mn, Pb, Ni and Zn) by algae whereby bioconcentration factors (BCF) ranged from 1.0 to 42 in some of the studies. Generally, metal levels in soils and selected organisms were much higher than those in water samples which further confirm possible accumulation. Since some aquatic organisms are consumed by humans, there is potential for the heavy metals to cause cancer and kidney damage. The studies done in Malawi compared well to those conducted elsewhere. The degradation of water resources by heavy metals compromises sustainability of water bodies and vital aquatic ecosystems hence negatively impacting on Integrated Water Resource Management (IWRM) efforts. This calls for periodic heavy metal monitoring and identifying ways of reducing their release into the environment.

Key words: Environment, heavy metals, pollution, public health, Malawi.
 

African Journal of Soil Science ISSN 2375-088X Vol. 12 (8), pp. 001-011, August, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Cytotoxic Effects of Emericella nidulans EGCU 312-Derived Secondary Metabolites on Cancer Cells

Neveen M. Khalil¹*, Emad A. Shalaby², Dalia M. I. A. Ali¹, Enas M. Ali¹ and Ahmed M. Aboul-Enein²

¹Botany and Microbiology Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
²Biochemistry Department, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.

Accepted 12 May, 2024

Abstract

The fungus, Emericella nidulans was isolated from soil. The ITS region of 5.8S rRNA of the isolated fungus was amplified and sequenced. E. nidulans EGCU312 was given an accession number: KC511056 in the NCBI GenBank. Twenty one (21) fractions were obtained from the ethyl acetate extract of fungal filtrate. Fraction no. 12 showed the highest antioxidant activity with 81.54% at 200 µg/ml. High anticancer activities (against EACC cell line) ranging between 64.3 and 87.7% at 200 µg/ml, were exhibited by fractions no. 1, 2, 4, 9, 12 and 20. The mode of action of anticancer activity was studied by measuring activities of lactate dehydrogenase (LDH) and caspase-3. Fraction no. 12 gave the highest effect (2249.2 U/l) in LDH released as compared to control cells (1127.7 U/l) and caused a 1.56-fold increase in caspase-3 activity. Interestingly, fraction no. 12 caused 100% inhibition of Staphylococcus aureus and Escherichia coli at 50 µg/ml, and Aspergillus fumigatus at 100 µg/ml. The minimum bactericidal concentrations (MBC) of this fraction were 4 and 10 µg/ml for S. aureus and E. coli, respectively, while the minimum inhibitory concentration (MIC) was 45 µg/ml against A. fumigatus. GC-MS profile of fraction no. 12 showed 21 compounds, six of which, that is, 2-methylbenzylamine, N-heptyl-N-octyl; naphthalene, 2,3,6-trimethyl-; octadecanoic acid, ethyl ester; 1,2-benzenedicarboxylic acid, butyl octyl ester; tributylacetylcitrate; 1,2- and benzenedicarboxylic acid, diisooctyl ester, were of known biological activities.

Key words: Emericella nidulans EGCU 312, antioxidant, anticancer, antimicrobial.
 

African Journal of Soil Science ISSN 2375-088X Vol. 12 (7), pp. 001-008, July, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Factors Affecting Nodulation Efficacy of Bradyrhizobium japonicum Inoculant Strain WB74 on Soybean (Glycine max L. Merrill)

Ahmed Idris Hassen*, Francina L. Bopape, Isabella H. Rong and Galaletsang Seane

Agricultural Research Council, Plant Protection Research Institute (ARC-PPRI), Private bag X134, Queenswood 0121, Pretoria, South Africa.

Accepted 14 April, 2024

Abstract

Lack of indigenous soil rhizobia that colonize and nodulate soybean (Glycine max L. Merrill) roots is a common problem of South African soils. Bradyrhizobium japonicum strain WB74 has long been used as an effective commercial inoculant strain for soybean since its introduction in 1998. This paper investigates the major limiting factors involved in the nodulation efficiency of B. japonicum WB74 that affect soybean growth and yield in South Africa. Methods including analysis of soil physicochemical properties, farmers’ management practices and quality control tests of locally manufactured inoculant products were employed. Inoculant’s strain verification was conducted using phylogenetic analysis of the 16S ribosomal RNA of the Bradyrhizobium strains in each of the inoculant product. The major findings of this study is that nodulation failure of introduced B. japonicum is caused by a combination of several limiting factors such as acidic nature of the soils as well as poor soil nutrition status especially that of phosphorous. Nodulation failure was also prominent in the soybean farms where there was no proper soil management practice. Results of the viability and shelf life studies also indicate that nodulation failure is caused by using sub-standard soybean inoculants products available on the market.

Key words: Bradyrhizobium japonicum WB74, inoculants, nodulation, quality control.

African Journal of Soil Science ISSN 2375-088X Vol. 12 (6), pp. 001-008, June, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Exploring the Impact of Antimicrobial Volatile Organic Compounds on the Antioxidative Pathways of Guignardia citricarpa

Mauricio Batista Fialho¹, Giselle Carvalho², Paula Fabiane Martins², Ricardo Antunes Azevedo² and Sérgio Florentino Pascholati¹*

¹Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura "Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900, Piracicaba, SP, Brazil.
²Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900, Piracicaba, SP, Brazil.

Accepted 7 April, 2024

Abstract

Volatile organic compounds (VOCs) produced by the yeast Saccharomyces cerevisiae strain CR-1 are able to inhibit the development of the fungal phytopathogen Guignardia citricarpa, causal agent of the disease citrus black spot. Antimicrobial VOCs have potential applications to control plant pathogens; however, there is limited information on the action mechanisms. It is possible that VOCs trigger the accumulation of harmful levels of reactive oxygen species. Therefore, this work aimed to evaluate the effect of the artificial mixture of VOCs, constituted by alcohols and esters identified from S. cerevisiae, on the antioxidant system of G. citricarpa. The VOCs at 0.48 μl/ml of air space completely suppressed the mycelial growth and reduced the respiratory rate. Increased activity of the antioxidant enzymes superoxide dismutase and catalase in the first 24 to 48 h of exposure to the VOCs indicating intracellular accumulation O2• - and H2O2, respectively was observed; however, the antioxidant glutathione pathway was not activated. In addition, increased lipid peroxidation was detected, confirming the oxidative stress process. Therefore, it was reported for the first time the disruption of the cellular redox homeostasis in microorganisms caused by VOCs. This knowledge is important to better understand the action mechanisms of antimicrobial volatiles and to develop safer fumigants to control postharvest diseases.

Key words: Antifungal, citrus, fumigation, stress response.