Division of Agronomy

Agricultural risks from changing snowmelt - Article in Nature Climate Change


20 April 2020: Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipitation falling as snow and the timing of snowmelt, which may have profound effects on food production in basins where irrigated agriculture relies heavily on snowmelt runoff.

In an article published today in Nature Climate Change global patterns of snowmelt and agricultural water uses are analyzed to identify regions and crops most dependent on snowmelt water resources. Hotspots exist primarily in high-mountain Asia (the Tibetan Plateau), Central Asia, western Russia, western U.S., and the southern Andes. Using projections of sub-annual runoff under warming scenarios, basins are identified that are most at risk from changing snowmelt patterns. Under the 4-degree Celsius warming scenario, the researchers project that the share of irrigation water demand met by snowmelt in the San Joaquin Basin (US) decreases from 33 percent to 18 percent. In the Colorado Basin (US), the share of water demand met by snowmelt decreases from 38 percent to 23 percent and in the River Po basin (Northern Italy) even from 29 percent to 9 percent. The study highlights basins and crops where adaptation of water management and agricultural systems may be especially critical in a changing climate.

The Division Agronomy contributed simulation results for crop specific monthly irrigation water requirements at global scale to the study and collaborated with 11 research teams from US-American universities.

Link to the article in Nature Climate Change
Link to the press release of the University of Göttingen

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Local food crop production can fulfil demand for less than one-third of population - Article in Nature Food

Food flow production consumption

17 April 2020: In an article published today in Nature Food a global analysis of the minimum distance between food production and food consumption is presented for major food crops. Survey data from international databases and simulation results of a global crop model are used to describe spatial patterns of crop production and consumption for temperate cereals, maize, rice, tropical cereals, tropical roots and pulses. Combined, these crops these crops account for approximately 47% of the globally traded calories. Then an optimization approach is used to minimize either the distance or the travel time between the locations of food production and consumption.

The results show that only 11-28% of the global population can fulfil their demand for specific crops within a 100 km-radius, with substantial variation between different regions and crops. For 26-64% of the population, that distance is greater than 1000 km. While yield gap closure and food loss reductions could favour more local food systems, particularly in Africa and Asia, global supply chains would still be needed to ensure adequate and stable food supply.

6 research teams located in Finland, the USA, Australia and Germany collaborated to perform this study to make an important contribution to the ongoing debate about consequences of the globalization of food supply chains versus local food movements and food sovereignty discourses.

Link to the article in Nature Food
Link to the article via Sharedit (open access, read-only)
Link to the press release of the University of Göttingen

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GHG emission savings by oil palm plantations challenged - Article in Nature Communications

Flux tower oilpalms small

27 February 2020: In an article published today in Nature Communications a team headed by Ana Meijide investigated the effect of palm-oil biodiesel on greenhouse gases for the entire life cycle. The researchers found that using palm oil from first rotation plantations where forests had been cleared to make way for palms actually leads to an increase in greenhouse gas emissions compared to using fossil fuels. However, there is potential for carbon savings in plantations established on degraded land.

Link to the article in Nature Communications
Link to press release of the University of Göttingen

Contact at the Division Agronomy: