New funding round with money from the Knowledge Exchange FundHow Orchards in Altes Land Could Slow Down Climate Change

17 November 2023, by Christina Krätzig

In 2023, Universität Hamburg funded 13 research projects from the Knowledge Exchange Fund. This year’s application call focused especially on projects that initiated cooperation between scientists and non-scientists. We introduce one of the projects below.

Fruit has been cultivated intensively in Altes Land for 300 years. More than 10 million apple, cherry, pear, and plum trees grow in the region, where one orchard gives way to the next. Altes Land is the largest continuous fruit-growing region in Germany. 

“The soils in the individual areas are much more homogeneous than we expected,” explains soil expert Prof. Dr. Lars Kutzbach of Universität Hamburg. In his current knowledge exchange project, the head of the research group on soils in the climate system at the Institute of Soil Sciences would like to initiate a knowledge network for the sustainable exploitation of fruit-growing soils in Altes Land. One focus lies on the study of the soil’s humus budget. This is vital to fertility. Moreover, dead organic matter binds carbon. If this carbon remains in the soil, it does not enter the atmosphere as carbon dioxide, so humus-rich soils contribute to slowing down climate change.

Yet the features of fruit-growing soils in Altes Land vary considerably from area to area, says Kutzbach. This is due, on the one hand, to agricultural methods used by the farmers there. The methods of soil cultivation and the type and amount of organic fertilizers have great impact on the development of humus and thus the storing of carbon.

On the other hand, the history of individual areas plays an important role. “They have been drained for hundreds of years using trenches,” explains Kutzbach. “But that is not a static system. Trenches are dug or filled in as needed and over time, water management influences the development and features of soils.” Furthermore, he continues, some areas were leased to one of the many brickwork factories in Altes Land. To extract clay for brick manufacture, the topsoil was removed. You can see still this in the soils today.

Kutzbach would like to recruit as many fruit farmers as possible for his knowledge exchange project

“A few families have already been cultivating their land for over 10 generations,” he says. Many think long-term and wish to preserve the fertility of their soils for the future. Many also want their work to contribute to the struggle against climate change and farm in a way that the soil binds as much carbon as possible. “This kind of farming could also be a sales argument or, in the future, financially supported as a contribution to a more sustainable societal transformation,” says Kutzbach.

To set up the transdisciplinary real-life fruit-growing lab in Altes Land, Kutzbach is cooperating with the sociologist Prof. Dr. Simone Rödder from the Department of Social Sciences at Universität Hamburg. She will organize a workshop for everyone involved so they can express their expectations and discuss eye-to-eye.  “We would like for the real-life fruit-growing soils lab to incorporate the knowledge of everyone involved so that we can arrive at a common understanding of the issue and set up and run the resulting knowledge network as a win-win situation for all,” explains Rödder. The expert for transdisciplinary dialog sees this as an essential condition so that fruit farmers will also become researchers in the long-term. Alongside the Esteburg Fruit-Growing Centre Jork, Hamburg’s Ministry of Environment, Climate and Agriculture is an important project partner.

As common in soil research, Kutzbach and his team will analyze many of the soil samples in the lab. Kutzbach also believes, however, that it should be possible using standardized photos to gain an impression of the quality and density of humus layers. “Because humus is a different color from other soil layers, we want to test whether farmers can use spades and a digital camera to contribute by reducing the costly lab analyses to a minimum.”

The project will initially receive €30,000 for 9 months. Soil expert Lars Kutzbach and sociologist Simone Rödder, both active in the Cluster of Excellence Climate, Climatic Change, and Society (CLICCS) at Universität Hamburg, hope that their project teams will be able to initiate and realize a long-term research project during the knowledge exchange project.