NEWSLETTER#54 - SOCIETY OF AFRICAN EARTH SCIENTISTS

Volume 14, Issue 1, January - March 2025

 

CONTENT

Chair's Foreword

Indigenous Soil Management Practices

Earth Science Events

References and selected reading

 

Chair's Foreword*

In the current issue we revisit the topic of indigenous soil management practices.

 Africans have been managing and conserving their soil and water and soil fertility for millenia. However, the recent  history of the continent including its colonisation and neo-colonialism, has seen an adverse effect on African soil and soil fertility. Consequently, much of Africa’s landmass has suffered long term depletion of nutrients,  moisture  and soil material.

   Western modes of agricultural land use in Africa such as intensive monocrop production repeatedly employed on the same land without fallow periods (as indigenous modes of agriculture employ[1] ) has mainly contributed to this degeneration of soils along with the environmental irresponsibility of some extractive industries that actually pollute the land - which is another matter.  The degradation of the land we concern ourselves with here takes the form of  the loss of soil due to erosion, loss of vegetation as well as soil nutrients leached out by rainfall and carried away by overland flow.

   In the current day  we know that a key solution to fixing our degraded lands lies in  employing African indigenous technology.

This has been well established in the three decades since the output of the valuable 1992 report by the International Fund for Agricultural Development (IFAD) [2] by ongoing  follow up work in the Sahel countries [3] where large areas of land were rehabilitated and hundred of thousands of tons of additional amounts of food were produced as a result of applying these simply enhanced indigenous techniques. 

Indigenous Soil Management Practices in Africa

The purpose of this newsletter's focus on indigenous soil management practices is for the Society to 

a) Encourage African use of indigenous technology, enhanced and improved as needed

b) Disseminate the  Knowledge of indigenous technology and its applications within Africa and the African Diaspora.

We focus on the most well known and documented practices, still being employed on the continent today.

Acacia albida tree

1) Planting Acacia trees

Planting the acacia albida tree fixes nitrogen in the soil via symbiotic bacteria. The tree sheds leaves during the rainy season which lead to more organic matter in the soil. This is known to improve soil moisture retention.

   The trees also reduce wind erosion due to the resistance provided by their canopies. These canopies also provide a cover to prevent soil loss by direct rainfall.

   The picture also shows a termite mound, which we recall from last newsletter, is also incorporated as part of a system of indigenous soil management practices[2a].

Applying mulch

2) Mulching

This is the traditional technique of protecting the soil through covering it with organic material to protect it from direct rainfall and sunshine. It is effective in combating weeds. It is widely known to improve crop resilience in West Africa [4].

Stone Bunds

3) Stone Bunds

Stone bunds are a line of stones arranged along the contours of the land  in order to slow the flow of the water and trap sediment and  organic material. In the long term, this enriches the soil. The bunds have the effect of reducing the amount of runoff and mitigating against the nutrient-rich top soil loss. The increased infiltration brought about will lead to more rapid groundwater recharge.

   In the northern Ethiopian highlands large scale stone bunds building programmes were implemented to curb soil erosion. The study of the programmes concluded that crop yields increased by 7% compared to yields when there were no stone bunds[5].

4) Trash Lines

These are obstructions/barriers arranged to slow down overland flow or runoff draining from the catchment and hence reduce erosion.  They consist of crop and plant residues and debris. They serve to eventually  increase infiltration of water and hence assist in the groundwater recharge. They accumulate organic matter.

Terracing - Rwanda

5) Terracing

This practice refers to the stepped platforms on slopes constructed across terrain in order to manage erosion and facilitate farming on steep slopes. The stepped constructions serve to greatly reduce the energy of the runoff and slow its velocity. The flattened terrain allows for greater water infiltration and hence more water retention and speedier recharge of groundwater. It also assists in retaining soil nutrients that would have been washed away without stepped slopes.

   A study on the effect of terracing during the Ethiopian drought of 2015 provided evidence that terraces have potential to help farmers deal with current climate risks[6]. A meta analysis by Wei et al., 2016 [7] found that terracing was on average 11.5 times more efficient at controlling erosion than non- terraced plots.

By reducing plot steepness terraces affect soil composition, hydrology and hence plant growth. Since, as already mentioned, terraces improve groundwater recharge rates, as well as reducing runoff and enhancing the soil nutrients content. 

Check dam - Ethiopia

6)  Check Dams

These are small barriers built across  gullies (channels in the landscape created by erosive overland flow) using stones, logs, or earth to slow the flow of runoff. The dam serves to trap sediment and hence conserve soil as well as moisture. The effect is to recharge the groundwater and increase the level of the water table. The sediment also contains organic material which improves the organic material content of the soil, further improving its capacity to retain moisture.

   Check dams are used all over the globe for control of torrential flows. Through experience and numerous case studies, people have realised their advantages in land development, environmental improvement, agricultural production, erosion gully stability and the mitigation of intensive flooding[8].

Zai planting pits

7) Zai Planting Pits

In Burkina Faso, the traditional form of agricultural planting pit was enhanced. The Zai planting pits are larger. Zai planting pits are 30-40cm in diameter and 10-20 cm deep. The bottom of the planting pit is lined with manure, which retains moisture in the planting pit as well as providing fertiliser for the crops planted in the pit.

   As emphasized by further studies in Nigeria [9], it is accepted that Zai along with other indigenous techniques are an effective way of improving degraded land and reducing vegetation loss and increasing  bio-diversity. Progress was seen in Niger and Burkina Faso where people rehabilitated many hectares, and increased the food yield many fold. In the report by Reij et al [10] various methods applied in Burkina Faso including Zai rehabilitated 200,000 - 300,000 ha and resulted in additional yield of 80,000 tons of food. In Niger, an even greater land area was rehabilitated: 5 million ha and there was an additional yield of 500,000 tons of food.

Earth Science Events

20 May 2025

International Conference on Environmental and Life Sciences

VENUE: Kenema, Sierra Leone

21-22 May 2025

Environment Social and Governance (ESG) Climate Africa Summit

VENUE: Nairobi, Kenya

2 June 2025

International Conference on Environmental Science & Engineering

VENUE: Gulu, Uganda

18–21 August 2025

VISION: We are excited to announce the TC/ESG25 Conference, a collaboration between the Transformations Community, the Earth System Governance Project (ESG), and Wits University. 

VENUE: Johann & Krugee National Park, South Africa

1  September 2025

International Conference on Environmental Science & Engineering

VENUE: Kisumu, Kenya

5 September 2025

International Conference on EEnvironmental Meteorology & Climatology

VENUE: Bamako, Mali

References

[1] Bado, V., Savadogo, P., et al., Technical Report. Restoration of Degraded Lands in West Africa Sahel: Review of Experiences in Burkina Faso and Niger, International Fund for Agricultural Development (IFAD).

[2] Soil and Water Conservation in  Sub-saharan Africa, International Fund for Agricultural Development (IFAD), Rome 1992.

[2a] Newsletter #53 - Society of African Earth Scientists. 

[3] Reij, C., Smale, M., and G. Gray, Re-Greening the Sahel: Farmer-led Innovation in Burkina Faso and Niger, in Miliions fed: Proven success in agricultural developments, International Food Policy Research Institute,  Washington 2009, p.53-58.

[4] Lamers, J., Bruentrap, M., and Buerkert, A., The Profitability of Traditional and Innovative Mulching Techniques Using Millet Crop Residues in the West African Sahel, Agricultural Ecosystems and Environment, Vol. 67, Issue 1, January 1998, pages 23-35.

[5] Vancampout, K., Nyssen, J., Gebremichael, D., et al., Stone bunds for soil conservation in the northern Ethiopian highlands: Impacts on Soil Fertility and Crop Yield, Soil and Tillage Research, Vol. 90, Issues 1-2, November 2006, pages 1-15.

[6] Kosmowski, F., Soil Water Management Practices (terraces) helped to mitigate the 2015 drought in Ethiopia, Agricultural Water and Management, Vol. 204, 31 May 2018, pages 11-16. https://doi.org/1016/j.agwat.2018.02.25

[7] WeiWei et al., Global synthesis of the classifications, distributions, benefits and issues of terracing, Science Direct, Elsevier, 2016. https://www.sciencedirect.com/science/article/pii/S0012825216301313

[8] Abbasi, N.A., et al,  The use of check dams in watershed management projects: Examples from around the world, Sci. Total Environ. 2019.

[9] Danjuma, M.N., and Mohammed, S., Zai Pits System: A Catalyst for Restoration in the Dry Lands, Journal of Agriculture & Veterinary Sci., Vol. 8, Issue 2, Ver. 1 (2015).

[10] Reij, C., Smale, M., et al. Ibid.

 

*Board of the Society of African Earth Scientists: Dr Enas Ahmed (Egypt), Osmin Callis (Secretary - Guyana/Nigeria), Mathada Humphrey (South Africa), Damola Nadi (Nigeria), Dr Chukwunyere Kamalu (Chair - Nigeria).

NEWSLETTER #53 - SOCIETY OF AFRICAN EARTH SCIENTISTS

 

Volume 13, Issue 4,  October - December 2024

 

CONTENT

Chair's Foreword

The Contribution of Termite Mounds to Local Soil Fertility

Earth Science Events

References and selected reading

 

Chair's Foreword*

In the current issue we review the importance of termite mounds to soil health. Termites are often referred to as nature's ecosystem engineers; a title that is merited by the benefits termites impart to the surrounding soils through their remarkable mound constructions and intra-soil activities.

THE CONTRIBUTION OF TERMITE MOUNDS TO LOCAL SOIL FERTILITY

To highlight how effective termite mounds can be in enhancing soil health in the African savannah, we briefly consider the key elements or qualities that indicate good soil health.

   According to African highland farmers in Kenya [1], the two most prominent indicators of soil health are vegetation performance and soil colour which are indicators common to all 9 countries featured in the study. In addition to these we must also take note of up to 16 parameters that feature here as indicators of good soil health. Four prominent indicators in this group are shown below : 

1) moisture infiltration and retention

2) soil structure

3) amount of organic material

4) sufficient nutrients for plant growth in the form of nitrogen, phosphorous and  potassium.

   Having reviewed  key soil qualities that indicate a healthy soil we can  see why termites are regarded as ecosystem engineers. We can see that precisely the missing elements to make healthy soils are added by the actions of these creatures.

   Through the construction of termite mounds the termites create an environment with greater biodiversity, and local soil that has greater level of soil health and fertility.

   Termites burrow deep into the soil (to depths of > 1m) bringing in organic material foraged from eating plant material to build the mound. In the process they create mound and soil structures having good infiltration capacity as well as significant amounts of organic material. This helps the mound and surrounding soil in improving moisture retention.

 Termite mounds also contain significant amounts of nitrogen, phosphorous and potassium, the elements so much needed to stimulate plant growth and enable processes like photosynthesis (in the case of nitrogen).

    Rainfall has the tendency to leach the contents out of the termite mounds so that these chemicals and organic matter are transported by runoff to the surrounding soil and groundwater.  Termite mounds are efficient in capturing carbon from the atmosphere [2]. An investigation into calcareous termite mounds on the west coast in South Africa inhabited by southern harvester termites and enriched by soil organic and inorganic carbon and soluble minerals, offer carbon sequestering via the leaching of carbonates into the groundwater.

   The termites burrow deep into the soil helping to improve the mound and surrounding soils structure, allowing for greater water infiltration and aeration. Studies in China [3] found that when termite mounds were abandoned the microbial communities in the surrounding soils resembled that of the mound. Furthermore, the soil physico-chemical properties, including water retention, soil pH, organic matter and nitrogen and phosphorous levels were closely associated with soil microbial communities.

Earth Science Events

October  6-9, 2024

XVIII African Regional Conference  on Soil Mechanics and Geotechnical Engineering

VISION:  https://algeos-dz.com/18ARC.html

VENUE: Hammamet, Tunisia

6 January 2025

International Conference on Environmental Meteorology and Pollution

VENUE: Abuja, Nigeria

10 February 2025

International Conference on Environmental Chemistry and Engineering

VENUE: Suez, Egypt

19 February 2025

International Conference on Soil Productivity and Quality

VENUE: Alexandria, Egypt

26 February 2025

World Congress on Soil and Water Sciences

VENUE: Giza, Egypt

21-22 May 2025

ESG Climate Africa Summit

VENUE: Nairobi, Kenya

August18–21, 2025

VISION: We are excited to announce the TC/ESG25 Conference, a collaboration between the Transformations Community, the Earth System Governance Project (ESG), and Wits University. 

VENUE: Johann & Krugee National Park, South Africa

References

[1] Eze, Samuel et al, Farmers indicators of  soil health in the African highlands, CATENA, Volume 203, August 2021, 105336

[2] Francis, M.I, et al., Calcareous termite mounds in South Africa are ancient carbon reservoirs,  Science of the Total Environment, 926 (2024).

[3] Chen, Chunfeng, et al., Effect of termite mounds on soil microbial communities and microbial processes: Implications for soil carbon and nitrogen cycling, Geoderma 431(2023), 116368.

 

*Board of the Society of African Earth Scientists: Dr Enas Ahmed (Egypt), Osmin Callis (Secretary - Guyana/Nigeria), Mathada Humphrey (South Africa), Ndivhuwo Cecilia Mukosi (South Africa), Damola Nadi (Nigeria), Dr Chukwunyere Kamalu (Chair - Nigeria).

NEWSLETTER #52 - SOCIETY OF AFRICAN EARTH SCIENTISTS

 

Volume 13, Issue 3,  July- September 2024

 

CONTENT

Chair's Foreword

Review of APET Working Paper

Earth Science Events

References and selected reading

 

Chair's Foreword*

In this issue we critically review the African Union Working paper on Emerging Technologies (APET)[1]. In some ways it is a welcome report. The continent is obviously in need of policies that can be implemented to drive an acceleration of science, technology and innovation developments. However, it is not clear that this report can adequately guide such developments on its own  without comment, or review to help the reader. Hopefully this critical review can enable the reader to discern some of the most valuable information and research that it offers.

REVIEW OF THE AFRICAN 

UNION WORKING PAPER 

ON

EMERGING TECHNOLOGIES

(APET)

Strengthening the technology and innovation capabilities of African countries is critical to achieving the African Union Agenda 2063 [2] and the UN Sustainable Development Goals[3], which more or less universally are agreed will benefit African socio-economic development and therefore there has been a concerted drive to focus on the improvement of African human resources capacity towards science and technology and innovation skills.

   The APET report encourages efforts to broaden and mobilise participation of African citizens possessing the requisite scientific skills that can address Africa's current challenges; from Sustainable Development to climate change mitigation and disaster recovery and aversion.

   The report suggests that enhancing a culture of science among African citizens will lead to science, technology and innovation (STI)  progress and formulation. The APET report holds that African led scientific findings and a culture of scientific thinking can benefit the society by nurturing scientific innovation. The report holds that enabling and supporting a scientific culture in Africa will give rise to a strong foundation for socio-economic development and growth on the continent. The APET Working Paper Report recognises with the rapid progress seen in  information technology, that without scientific advancement the continent will lag  "socio-economically" far behind the rest of the world.

   In its analysis of science culture in Africa the report has noted that indigenous knowledge and innovation history informs us that African peoples have always possessed a scientific culture; but due to widespread ignorance of its history it has been assumed that African scientific culture is non-existent. Several reports cited by the APET study demonstrate to us that Africans have always been at the forefront of important scientific developments, with the advent of the sciences of mathematics, metallurgy, astronomy, stratigraphy, medicine and surgery, and many other examples on the African continent which the report documents.

   Perhaps controversially, the report does claim that African traditional beliefs such as the concept of personal immortality (where for instance immortality is  guaranteed by having offspring to retain the memory of deceased parents/ancestors) impede socio-economic and scientific progress; since it encourages overpopulation. However, this would appear to be a narrow view of African beliefs and their impact on societal outcomes. Furthermore, it has never been established scientifically that Africa is an overpopulated continent, beyond mere popular mythology and hearsay that is often parroted and suggested without inspection of the facts. For a fact we know that the combined populations of USA, Mexico, China, Iberian Peninsula, Western Europe, Japan, India and UK total 3.796 billions compared with Africa's 1.38 billions; whilst the land area of these combined countries totals just 27.02 million sq. km compared with Africa's 30.8 million sq km. So this often repeated assertion of African overpopulation is patently false. Yet even the African Union paper suggests this falsehood without inspection of the facts.

   The APET report goes on to chart Africa's historic capacity in STI,  noting its role in the early developments in

- chemistry and metallurgy [4]

- mathematics and geometry [5]

- medicine and surgery [6]

   It has been observed by earlier reports - for example, in the study of land and soil conservation practices in Africa - that western science and technology is often superimposed in a bid to eradicate indigenous African science and technology.  A thirty-two year old study of soil and water conservation in Africa [7] notes how modern western soil and water conservation solutions are often imposed on top of indigenous African systems that have existed for thousands of years. These include ancient terracing systems and systems of land management such as shifting cultivation and multi-cropping as opposed to mono-cropping which have served in modern times to deplete the soil quality in terms of material loss and  fertility loss.

   The report concludes with some recommendations. These include making the curriculum in Science in schools relevant to African peoples needs and realities. African governments should provide the infrastructure (e.g., technology hubs, etc) to enable a scientific culture. Also significant, in the papers conclusion, are the observations of numerous modern frameworks that now exist to guide development. These include and are not limited to: AU Agenda 2063, Science Agenda 2030,  Leading Integrated Research for Agenda 2030 (LIRA 2030) and Alliance for Advancing Excellence in Science in Africa (AESA).

   Finally, the report is rightly critical at the government level and continental level of how African governments are often content to import foreign solutions to  address African problems rather than encouraging indigenous solutions through intra-African collaboration. Furthermore, the report rightly notes too few Africans in decision-making positions showing sufficient interest in embracing the role of science and technology in African development.

   A recent and stark example of this cited failure includes the decision-making body of the African Union itself in the ongoing case of the Great Green Wall project. This grand project aims to halt the further southward encroachment of the Sahara desert and revitalise degraded landscapes across the 8,000 mile Sahelian belt of Africa, crossing some 21 countries in the process. It is an example on a grand scale, of how our African decision-makers can display lack of creativity and political will in seeking and encouraging intra-African solutions, and collaboration leading to formulation of African solutions to African problems rather than waiting for investments and solutions to be offered from abroad by foreign governments and institutions. This most definitely needs to change if African development is to be spurred on by indigenous African science, technology and innovation.

Earth Science Events

October  6-9, 2024

XVIII African Regional Conference  on Soil Mechanics and Geotechnical Engineering

VISION:  https://algeos-dz.com/18ARC.html

VENUE: Hammamet, Tunisia

6 January 2025

International Conference on Environmental Meteorology and Pollution

VENUE: Abuja, Nigeria

10 February 2025

International Conference on Environmental Chemistry and Engineering

VENUE: Suez, Egypt

19 February 2025

International Conference on Soil Productivity and Quality

VENUE: Alexandria, Egypt

26 February 2025

World Congress on Soil and Water Sciences

VENUE: Giza, Egypt

21-22 May 2025

ESG Climate Africa Summit

VENUE: Nairobi, Kenya

August18–21, 2025

VISION: We are excited to announce the TC/ESG25 Conference, a collaboration between the Transformations Community, the Earth System Governance Project (ESG), and Wits University. 

VENUE: Johann & Krugee National Park, South Africa

References

[1] African Union High Level Panel on Emerging Technologies[APET], Working Paper Series 1, African Union Development Agency, November 2021.

[2] Agenda 2063, The Africa We Want, Framework Document, African Union, September 2015.

[3] Transforming Our World: The 2030 Agenda for Sustainable Development, UNDP, 2015.

[4] New York Times (South African edition), 8 February, 1979. See also Debra Shore, Steel-Making in Ancient Africa in Black's in Science ancient and modern, I. Van Sertima (ed.), Transaction Books, New Brunswick and London, 1985, pp.157-175.

[5] Kamalu, Chukwunyere, THE ISHANGO BONE: The World's First Known Mathematical Sieve and Table of the Small Prime Numbers, Society of African Earth Scientists, AfricArXiv. February 28, 2021. doi:10.31730/osf.io/6z2yr. See also Diop, C.A., Civilization or Barbarism, Lawrence Hill Books, 1991. pp.231-243.

[6] Finch, Charles S., African Background to Medical Science, in Black's in Science ancient and modern, I. Van Sertima (ed.), Transaction Books, New Brunswick and London, 1985, pp. 157-175.

[7] Soil and Water Conservation in Sub-saharan Africa, International Fund for Agricultural Development, Rome, 1992.

*Board of the Society of African Earth Scientists: Dr Enas Ahmed (Egypt), Osmin Callis (Secretary - Guyana/Nigeria), Mathada Humphrey (South Africa), Ndivhuwo Cecilia Mukosi (South Africa), Damola Nadi (Nigeria), Dr Chukwunyere Kamalu (Chair - Nigeria).