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New solutions for improved agriculture in Africa

Researchers from the Department of Agroecology at Aarhus University have just completed a research project in Ghana, which points to new solutions to increase crop yield in African agriculture, and thus can slow the rate of deforestation. The project has shown that irrigation as well as production and use of biochar can increase yields, as well as help to increase employment, improve the economy and provide a cleaner environment.

2020.04.24 | Camilla Brodam

Photo: Mathias Neumann Andersen

Imagine this: a new kind of agricultural production in Africa that offers greater crop yields, improves soil fertility, reduces deforestation, protects the environment and provides more growth and employment in the local area - all in a sustainable way tailored to local conditions and resources.

It sounds like a dream scenario, but nonetheless, it was the goal of the WEBSOC project when it started 6 years ago. The research project, which was awarded DKK 10 million from Danida, was a collaboration between Aarhus University, Copenhagen University, Aalborg University, the Technical University of Denmark, the University of Ghana and the University of Cape Coast. 

The Department of Agroecology at Aarhus University was the head of the WEBSOC project, which had two main purposes. One was to build research capacity at the two Ghanaian universities that were part of the project. And the second purpose was through research and trials to find solutions that could improve Ghana's agricultural production. 

Capacity building at universities

One of the aims of the WEBSOC project was to build research capacity at the universities in Ghana, which means, among other things, to educate more PhDs.

“Over the last six years, we have completed six PhD studies and four master's studies. Two of our post docs have obtained permanent positions at the University of Ghana. And we have produced more than 20 international scientific articles,” says Professor Mathias Neumann Andersen from the Department of Agroecology, who was the project leader.

In this way, WEBSOC has been instrumental in strengthening the research capacity at the universities in Ghana, but in fact, the group behind the project has succeeded in virtually all parts of the project.

The earth is sour

The WEBSOC project was aimed at changing some of the farming strategies in Ghana, so that simple, but modern, technologies could improve agricultural production. By using targeted irrigation, farmers can get extra growing seasons out of their fields, and by adding biochar, the quality of the soil will be improved and the yield in the field increased. Biochar is charred plant material, in Ghana, for example, it can be produced from residual products from the palm oil industry. The increased yield will create more growth and higher employment in the local area, thereby alleviating poverty. And with a higher yield in the fields, the need for deforestation is also decreasing. 

“Agricultural production in Ghana has been and still is dependent on deforestation. They simply need to use the land to grow crops and the tree for fuel. But deforestation has major negative consequences. Originally, 36% of Ghana was covered by forest. In 2000, that area was reduced to 10.2%, and now it is even smaller. And this has major implications for the local population when forests are cleared. The possibilities of obtaining firewood, timber, clean water and food from forests and biodiversity as a whole are limited. The soil is depleted and the yields stagnate as a result of erosion on the agricultural soil. And declining productivity leads to increased poverty among the already poorest population,” explains Mathias Neumann Andersen. 

The degraded land in Ghana creates major problems for agricultural production and it increases deforestation as farmers need larger and larger areas to grow their crops.

“The quality of the soil in Ghana is a major problem for agriculture. The soil is simply too acidic, it lacks calcium, which is not available locally. So, in the project we wanted to investigate if there were other opportunities to increase the quality of the soil without the use of calcium, and biochar is an option, but it must be produced locally before it is profitable,” explains Mathias Neumann Andersen.

Oven for biochar

In total, the project included 5 work packages, all of which should help to improve agricultural production. And the first was to develop an oven for biochar production. Along with DTU (Technical University of Denmark) they succeeded. The furnace produces biochar from waste products from palm oil extraction.

“The furnace produces both energy for refining the oil and biochar for agriculture, and local tests have shown that it can even significantly improve the working environment in the palm oil industry. Our PhD student got the idea to supply it with a chimney that lifts the smoke away from the work area. Last but not least, it eliminates the use of wood needed to heat the oil so water can be evaporated,” says Mathias Neumann Andersen.

Next, the project investigated the effect of biochar on soil quality, as well as its effect on yield. And the project showed that biochar has a lot of positive effects.

“Biochar is the only known mean of raising the carbon content of the earth in the long term, which is otherwise declining not only in Ghana but worldwide. And a declining carbon content in the soil contributes to the emission of greenhouse gases from agriculture. Biochar also increase the soil's aggregate stability, i.e. the soil's ability to withstand erosion. And precisely that is a growing problem in connection with stronger rainfall in the country. Last but not least, the addition of biochar has also increased the soil's pH value and fertility, including the availability of phosphorus, and this has resulted in large yield increases in our field trials,” says Mathias Neumann Andersen.

There are many benefits to using biochar for both the soil and the environment. By converting plant pulp into biochar and utilizing it in the field, CO2 emissions will be reduced. And by adding biochar to the soil, the storage of carbon in the soil increases. This in turn reduces CO2 emissions to the atmosphere further and increases the earth's ability to hold on to the water. When the soil is better at holding the water, fewer nutrients are washed out and the soil fertility is further increased.

Water is needed

The researchers have developed a cheap but fully automatic drip irrigation system that runs on solar energy for growing vegetables in small farms. The irrigation system enables cultivation in the dry season and thus greatly increased earnings during a period of the year when there is a shortage of vegetables. By watering in the dry season one can grow high value crops such as tomatoes, cabbage and okra. Farmers can achieve one or two growing seasons more in a year at times when prices are high. It increases agricultural earnings and consumer health. And the increased productivity will of course also lead to larger quantities of plant waste and thus the opportunity to increase biochar production further.

Effect of water and biochar

“We knew beforehand that irrigation would have an effect, but it surprised us that there was such an effect of biochar. This is probably because the soil is so acidic and has as low a phosphorus content as it has in Ghana. We saw that the use of biochar doubled the yield of okra. And in our experiment with corn we also saw similar great results,” says Mathias Neumann Andersen.

The normal yield of maize in Ghanaian agriculture is 1.5 tonnes per hectare. Using biochar alone, the yield increased to 2.5 tonnes per hectare. And as the researchers added irrigation to the experiments, the yield was increased to 6-8 tonnes of maize per hectare. Thus, the combination of biochar and irrigation caused the yield to increase massively.

“The system of biochar and irrigation has been successfully tested by farmers in Ghana. It's a win-win situation. Farmers receive higher yields from irrigation, improved soil fertility and less greenhouse gas emissions due to increased carbon storage in the soil. But these are at the same time measures that require investment otherwise there will be no long-term effect of biochar, and it is needed before it is profitable. Although we have had the trials running for three years now, it is too short a time to measure the long-term effect of biochar and whether it lasts. That is why we are so lucky that we are now embarking on a new project that will investigate just that,” says Mathias Neumann Andersen. 

The new project, which is the third project since 2008 focusing on improving agricultural production in Ghana. The project is called "Building vegetable farmers resilience to climate change". It runs from 2020 to 2025, and it builds on the WEBSOC project's irrigation and biochar project as a basis for improved agricultural production, greater yields, higher resilience to climate change, and emission of fewer greenhouse gases.

You can read more about the new project  ”Building vegetable farmers resilience to climate change” here.

Behind the project

Collaborators: Aarhus University, University of Copenhagen, University of Aalborg, Technical University of Denmark, University of Ghana and University of Cape Coast.

Funding: The project has been granted DKK 10 million. DKK from the Ministry of Foreign Affairs

Conflicts of Interest: None

Contact information: Professor and section manager Mathias Neumann Andersen, Department of Agroecology at Aarhus University. Email: mathiasn.andersen@agro.au.dk. Tel: +45 224 007 42

Research, Agro, DCA