African Journal of Soil Science

African Journal of Soil Science ISSN 2375-088X Vol. 12 (3), pp. 001-008, March, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Impact of Flaveria bidentis Invasion Chronosequence on Soil Bacterial Communities

Chaohe Huangfu, Huiyan Li, Xinwei Chen, Hongmei Liu and Dianlin Yang*

Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin, 300191, China.

Received 22 April, 2024; Accepted 31 November, 2024

Abstract

A new exotic weed, Flaveria bidentis, is spreading in central China where it forms dense monospecific patches modifying the structure of different native ecosystems and threatening native aboveground biodiversity. However, little is known about the consequences of such an invasion for soil bacterial community, especially its effect pattern at different invasion stages. In this study, soil samples were taken in native ecosystems that were uninvaded, partially invaded (transition), and severely invaded by F. bidentis. The bacterial richness and diversity in F. bidentis in rhizospheres soil was evaluated using denaturing gradient gel electrophoresis (DGGE) analysis. Different stages of F. bidentis invasion can trigger changes in soil physicochemical properties in particularly in available N and P F. bidentis invasion significantly decreased the richness of soil bacterial community, and the decline contents were positively correlated with invasion progress. In the invaded soils, bacterial species in Proteobacteria, Chloroflexi and Actinomycetes decreased with invasion, with the greatest reduction in relative abundance occurring for Proteobacteria, which was the dominant species in the native soils. Invasion of F. bidentis corresponded with an alteration in the structure of soil bacterial community, and soil microbial biomass as well, thus soil environment modification was expected to promote spreading of this exotic weeds in turn.

Key words: Biological invasion, Flaveria bidentis, soil nutrients, soil bacteria, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE).

African Journal of Soil Science ISSN 2375-088X Vol. 12 (3), pp. 001-016, March, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Bacterial Community Dynamics in Amazonian Dark Earth and Surrounding Soils

Amanda Barbosa Lima¹*, Fabiana de Souza Cannavan1, Mariana Gomes Germano^1,4, Francisco Dini-Andreote², Alessandra Monteiro de Paula³, Julio Cezar Franchini⁴, Wenceslau Geraldes Teixeira5 and Siu Mui Tsai¹

¹Laboratory of Cell and Molecular Biology, Centro de Energia Nuclear na Agricultura - CENA, University of Sao Paulo,
Piracicaba, Brazil.
²Department of Microbial Ecology, University of Groningen, The Netherlands.
³Department of Agronomy, Universidade Federal do Paraná, Palotina, Brazil.
⁴Brazilian Agricultural Research Corporation - EMBRAPA Soybean, Londrina, Brazil.
⁵Brazilian Agricultural Research Corporation - EMBRAPA Soils, Rio de Janeiro, Brazil.

Received 27 October, 2024; Accepted 10 January, 2025

Abstract

Amazonian Dark Earth (ADE) in the Brazilian Amazon is the main evidence left by pre-Columbian indigenous populations indicating that infertile soils can be transformed into highly fertile ground. Changes in vegetation cover and seasonality are likely to influence microbial communities; however, little is known about these effects on ADE. Therefore, this study compared the effects of two land use systems in ADE and adjacent soil (ADJ) during the rainy and dry seasons using biochemical and molecular tools. Bacterial community function was determined by community level physiological profile (CLPP), bacterial community structure by terminal restriction length polymorphism (T-RFLP), and bacterial community composition by pyrosequencing of the V4 16S rRNA gene region. Our results show that the community structure is highly affected by vegetation, in both, ADE and ADJ soils. Regarding community function, Average Well Color Development (from Biolog substrates) were higher in ADE than ADJ during the rainy season and kept the same pattern of substrate utilization during the dry season and finally, community composition showed to be influenced even at the level of family, mostly by soil type rather than vegetation. Collectively, our study provides insights into processes affecting the bacterial community assemblages in both, ADE and adjacent soils.

Key words: Amazonian soils, vegetation type, seasonality, soil bacteria.

African Journal of Soil Science ISSN 2375-088X Vol. 12 (2), pp. 001-013, February, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Impact of Organic and Inorganic Amendments on Acidic Soil Chemistry

Asmare Melese¹* and Markku Yli-Halla²

¹Department of Plant Science, Debre Berhan University, Ethiopia.
²Department of Food and Environmental Sciences, University of Helsinki, Finland.

Received 18 February, 2024; Accepted 9 October, 2024

Abstract

An incubation study was conducted for two months to evaluate the effects of different treatments on the inorganic P fractions and other chemical properties on an acidic soil. Four rates of lime and wood ash (3.5, 7.0, 9.2, 11.2 tons CaCO3 equivalent ha-1) were separately applied to obtain target soil pH values of 5.5, 6.0, 6.5 and a lower pH obtained with half of the lime requirement needed to bring the pH to 5.5. Three rates of mineral P fertilizer and manure P (32.5, 65, 130 kg P ha-1) were separately applied into the whole soil volume. Additionaly, wood ash (7 tons CaCO3 ha-1) and lime (7 tons CaCO3 ha-1) were combined separately with each of the manure and mineral P rates. The experiment was laid down in a completely randomized design with two replications. Lime and wood ash treatments showed a significant effect on the pH and exchangeable acidity compared to manure. The highest lime and wood ash rates (11.2 tons CaCO3 ha-1) increased the pH from 4.89 to 6.03 and 5.93; decreased the exchangeable acidity from 2.22 to 0.14 and 0.16 cmolc kg-1, respectively. The maximum increment in Olsen P by 132%, aluminum bound P (Al-P) by 160%, iron bound P (Fe-P) by 22% and oxalate extractable P (Pox) by 33% were observed by the application of mineral P at 130 kg P ha -1 plus wood ash (7.0 tons CaCO3 ha-1). Therefore, lime and wood ash applications in acidic soils can effectively ameliorate H+ and Al3+ toxicity and P deficiency.

Key words: Acidity, incubation, lime requirement, P form.
 

African Journal of Soil Science ISSN 2375-088X Vol. 12 (2), pp. 001-009, February, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Impact of Floodplain Conditions on Soil Quality in Cassava Agricultural Systems 

Abah R. C.*^1,2 and Petja B. M.^1,3

¹University of South Africa, Pretoria, South Africa.
²National Agency for the Control of AIDS, Central Area, Abuja, Nigeria.
³Water Research Commission (WRC), Rietfontein Pretoria, South Africa.

Received 19 July, 2024; Accepted 3 November, 2024

Abstract

The study was carried out to analyze soils from cassava farms in floodplain terrain of the River Benue. Cassava is the most extensively cultivated crop in Benue State. Soil samples were collected randomly from cassava farms owned by members of farming cooperative societies in Makurdi, Tarka, and Gboko Local Government Areas. These samples were analysed for physical and chemical properties. The pH was slightly acidic with a mean of 5.7 for surface soils and 5.7 for subsurface soils. The organic carbon content had a mean of 0.7% for surface soils and a mean of 0.72% for subsurface soils. The total percentage nitrogen had a mean of 0.05% for surface soils and 0.05% for subsurface soils. Available phosphorus had a mean of 8.48 mg kg-1 for surface soils, while subsurface soils had a mean of 5.66 mg kg-1. The base saturation percentage was 86.58% for surface soils and a mean value of 86.55% for subsurface soils. The values of micro-nutrients were all below tolerable limits. The study recommends the effective application of inorganic fertilizers such as NPK to optimize crop production. Governments should support farmers with credit facilities, agricultural laboratory services, and effective extension services.

Key words: Soil assessment, soil nutrients, organic carbon, phosphorus, nitrogen, micro-nutrients, River Benue, Nigeria.
 

African Journal of Soil Science ISSN 2375-088X Vol. 12 (1), pp. 001-011, January, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Impact of Land Use on Soil Organic Carbon Dynamics in Mount Cameroon National Park

Kum Christian Tegha¹* and Yinda Godwin Sendze²

¹Department of Environmental Science, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.

²Department of Agronomy and Applied Molecular Sciences, Faculty of Agriculture and Veterinary Medicine, University of Buea, Buea, Cameroon.

Received 18 August, 2024; Accepted 1 November, 2024

Abstract

Increasing effects of climate change has led to an urgent need for reliable estimates of the soil carbon pool (SOC) which is one of the carbon sinks in the world. This is especially true in Africa where there is lack of basic data. This study conducted in the southern part of Mount Cameroon National Park (MCNP) seeks to determine SOC patterns and estimate CO2 equivalence from SOC pool following land-use changes. Nine prominent land-use types were identified (under rubber, virgin forest reserve, oil palm, cassava, mixed cropping, tea, maize, banana and sugar cane). Soil samples were collected from 98 plots of 2,500 m2, each spread over the different land uses in five villages at 0 - 30 cm of soil. The collected Soils samples were analyzed for SOC and other physicochemical properties. Mean SOC ranged from 56.1± 11.00 t ha-1 (for rubber) to 225.24 ± 33.65 t ha-1 1 (for forest) giving an average for the area of 130.80 Mg/ha. The mean SOC in forest soil was significantly higher than that for cassava (p=0.038), oil palm (p=0.045) and rubber (t=4.849, p=0.0046). Losses in CO2 equivalence, as a result of land use change from forest to other land use systems, ranged from 234.15 (for mixed cropping) to 620.74 t/ha (for rubber). The study provided estimates of carbon pools for different land uses in MCNP. Mixed cropping was only second to forest in terms of SOC values indicating that agroforestry can mediate between food production and environmental protection.

Key words: Soil organic carbon, land use systems, CO2, carbon sequestration, soil quality.
 

African Journal of Soil Science ISSN 2375-088X Vol. 12 (1), pp. 001-017, January, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Effective Strategies for Soil Acidity Mitigation Using Specialized Liming Materials

Jessica Alves dos Santos¹*, Adriel Ferreira da Fonseca¹, Domenico Zocco² and Igor Vieira³

¹State University of Ponta Grossa, Av. Carlos Cavalcanti, Ponta Grossa, Paraná, Brazil.
²Omya International AG, P. O. Box 335, Baslerstrasse 42, 4665 Oftringen, Switzerland.
³Omya do Brasil Ltda, Av. Angélica, 2220, 2° andar, São Paulo, São Paulo, Brazil.

Received 13 April, 2024; Accepted 8 October, 2024

Abstract

Soil acidity has been the major limiting factor to farming activities in the tropics and subtropics. The objective of this study was to verify the efficacy of special liming materials, when compared with the dolomitic limestone, regarding the correction of soil acidity with variable charge in controlled conditions. Samples of a Typic Dystrudept and Rhodic Hapludox were collected from a of layer 0-20 cm, and used to carry out two experiments in a completely randomized design of 4 x 4 x 8 factorial design. Four liming materials were studied: dolomitic limestone (DL), granulated micronized calcite (GMC), granulated micronized dolomite (GMD) and carbonated suspension (CS). After they have been characterized, each liming material was added to the soils using doses that aimed to increase the base saturation (V) to 50, 70 and 90% and a control treatment was included. The treated soil samples were incubated at 23 ± 2°C and 60% soil water retention capacity for eight periods (0, 7, 15, 30, 45, 60, 75 and 90 days). The attributes active (pH), potential (H+Al) and exchangeable (Al3+) acidity and V were evaluated. The special liming materials GMC and CS were efficient enough to reduce the active potential and exchangeable acidity, and increase V in soils with variable charge.

Key words: Micronized liming materials, carbonated suspension, soil reaction, Inceptisol, Oxisol.