Humboldtians in Focus

Network for Sustainability

By Kristina Güroff

Amina Saied and Jens Gebauer are the personification of the Humboldt Network, and both work for the same goals: utilising local resources, preserving biodiversity and guiding young researchers through the academic jungle. 

There is a tropical forest sleeping peacefully on the shelves: piles of plastic containers, jars and bags full of strange seeds, shells, and fruit of every conceivable size, just waiting to be awoken to new life in the service of research.

The shelves can be found in the office belonging to agronomist, Jens Gebauer. Four years ago, he was a Feodor Lynen Research Fellow, hosted by a Sudanese Humboldtian; now he himself is the host for Georg Forster Fellow Amina Saied. When she arrived at the beginning of 2007, the young agronomist from Sudan brought new bags of supplies to replenish Jens Gebauer's store, the climatic chambers and the laboratory of the Department for Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics at Kassel University. She is investigating the salt tolerance of two varieties of wild fruit. Everything about Amina Saied is bright and shining: her eyes, her laugh, her bold blue clothes; but when she talks about the effects of salt stress on her painstakingly cultivated little plants her face puckers up as though she had bitten into a lemon. She just feels so sorry for the plants. But then she shrugs her shoulders, overcoming her misgivings with a gesture that says what will be, will be.

Given the increase in soil salination and desertification in Africa, her research is extremely relevant. Strong solar radiation in combination with low precipitation leads to high evaporation. Th is loosens the salt in the soil which increasingly penetrates the upper layers. However, soil salination can also be caused by incorrect artificial irrigation if the water introduces more salt than it carries away. Furthermore, due to intensive farming, much of the new soil gained from clearing is oft en only fertile for a short time. If these areas are subsequently used for grazing, the vegetation cover cannot renew itself; the unprotected soil dries out and erodes. Every year, millions of hectares of agricultural land get lost in this way. Amina Saied describes the situation in her own country, "In some parts of Sudan at the moment, huge monocultures of potatoes or wheat are being laid out, and so whole areas have been completely cleared of any vegetation that was there before. These monocultures are more susceptible to disease and pests and require a lot of fertiliser and pesticides. But people only think about profit, not about the environment."

Amina Saied and Jens Gebauer in the Greenhouse for Tropical Crops at Kassel University: Research to preserve biodiversity.
Amina Saied and Jens Gebauer
in the Greenhouse for Tropical
Crops at Kassel University:
Research to preserve
Foto: Kristina Güroff

Researchers offer grounds for hope

Understandably, cultivating fruit trees is a tall order when every day is a fight for survival. If my tree is only going to bear fruit in ten years, what am I supposed to live off today? So how can soil be managed ecologically and local resources be utilised better in future? These are the issues that occupy Jens Gebauer who spent almost two years in Sudan with his academic host, Kamal El-Siddig, from the Agricultural Research Corporation (ARC). He is a very good example of how the worldwide Humboldt Network thrives. Even before his stay abroad, Gebauer had met his later host, El-Siddig, in Berlin where he was doing research on the strength of a Georg Forster Fellowship. Then, in turn, a Feodor Lynen Fellowship took Gebauer to Sudan to investigate agroforestry systems involving the combined cultivation of annual cultures and perennials on the same area. This system could be a means of combating increasing salination and erosion. And this is where Gebauer's and Saied's research coincide. Wild fruit trees are often more salt tolerant, they have deeper roots than annuals and are thus able to draw water from non-saline soil layers. They also stabilise the soil and provide additional shade. Indigenous annual cereals like sorghum and millet can be cultivated beneath them and require less irrigation.

“In the confusion of buses and people in Khartoum, at the beginning you feel like a child who has only just learnt to walk but doesn’t know which way to go.”

Gebauer worked in El Obeid, an important market town 400 km south west of the capital, Khartoum, at the foot of the Nuba Mountains. He felt as helpless as a child when he first arrived, Gebauer comments. He can still remember only too well the confusion of the buses in Khartoum, his fear of disease, the strange food, and the incredible heat. but after a while, he had learned to appreciate the time and peace for contemplation in the savannah. In retrospect, he got to know himself much better in Sudan, Gebauer notes.

Settling down in Germany was not nearly so difficult for Amina Saied, especially as the period spent at Bonn University where she took her doctorate in 2004, meant she knew all about the difficult climatic conditions! This was when she first met her research colleague, Jens Gebauer. The only thing she misses, according to Saied, is the close-knit social life in her own country for which not even the touching care shown by her colleagues could compensate. But the only real source of worry had been the Immigration Office which had only issued her residence permit at the very last minute.

Closing the gap between theory and practice

The two varieties of wild fruit Saied has chosen to investigate in Kassel, Grewia tenax and Ziziphus spina-christi, are particularly suited to systematic cultivation. Her experiments are proving extremely promising: Grewia in particular appears to be very salt tolerant, and why this is, is currently being tested in the laboratory by chemical analysis. Roughly the size of a blackcurrant, the bright orange-red fruit of the Grewia tenax, a bush which reaches a height of three metres, shines just as brightly as the cherry-like fruit of the Ziziphus spinachristi, a tree which can grow to a height of ten metres. The fruit is collected by women and children and sold at market to be eaten fresh or dried. Both fruits are very nutritious. Because its juice is a frequent source of iron for children and pregnant women, Grewia fruit costs fifteen times as much as sorghum. The leaves and small branches provide animal feed. The roots and leaves are used for medical purposes. However, overexploitation leads to senescence: there is less fruit, which is harvested none the less from need or ignorance, and a vicious circle ensues.

Amina Saied subjecting her plants to salt stress in the climatic chamber.
Amina Saied subjecting her
plants to salt stress
in the climatic chamber.  
Foto: Kristina Güroff

Gebauer also registered the discrepancy between theoretical knowledge and practical use of wild fruit during his stay in Sudan. It is important to investigate and run practical trials on suitable methods of making the seeds germinate - the precondition for targeted cultivation. Saied has now done this in depth in Kassel and published the results for the first time. Her research should lead to concrete forestation recommendations for her colleagues in Sudan. Saied and Gebauer want to make sure that biodiversity and genetic resources are preserved and draw attention to the advantages of considering ecological aspects in the use of indigenous plants. "This is what we're interested in: using local resources. In the savannahs the farm structures are tiny; the people have to fight to produce their food. There's no investment out there like there is around Khartoum, and people have to search for their daily bread! If the harvest fails because of drought everyone heads off to collect wild fruit to keep them going through the next year," Jens Gebauer explains.

The Humboldt Network bears fruit

In 2006, Jens Gebauer and his head of department, Andreas Bürkert, started up an institutional partnership between their own institute and the ARC. In Sudan, Gebauer's former host, El- Siddig, manages the project which aims to improve urban agriculture in Khartoum. In spring 2007, Gebauer and a colleague from Kassel ran a course there for students from ARC and - facilitated by Amina Saied - from Khartoum University. Cooperation and exchange within the network open up perspectives for both Sudanese and German students and benefit everyone: the quality of individual research is significantly improved by interdisciplinarity and by drawing on different points of view, ideas and experience, Saied believes.

The benefits for the Humboldtians go beyond pure research. Amina Saied was able to take part in an International Deans' Course, for example, providing qualifications in university management for deans from Africa. This was extremely useful, Saied claims, because after she had returned from Germany in 2005, she had had to take on the leadership of her institute more or less unprepared.

To make sure the Humboldt Network continues to blossom and grow, Jens Gebauer was involved in founding the German Association of Humboldtians in Kassel this year. Now he has just submitted his thesis for a Habilitation, but like all true field researchers, he cannot resist the call to go out into the world: in summer 2008, he is planning the next stay at the partner institute. Hanging on the shelves next to the inventory list for his office is his sun hat - ready for action.

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Amina Saied, Jens Gebauer Amina Saied, Jens Gebauer

Dr. Amina Sirag Saied is head of the Department of Horticulture at Khartoum University in Sudan. She has been a Georg Forster Fellow since January 2007, researching at Kassel University together with Professor Dr. Andreas Bürkert and Dr. Jens Gebauer. From 2003 to 2005, Jens Gebauer was a Feodor Lynen Fellow in Sudan.

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