Underuse of phosphorus-based fertilizers in Africa currently contributes to a growing yield gap—the difference between how much crops could produce in ideal circumstances compared to actual yields.
This phosphorus-specific yield gap currently lies at around 10% for subsistence farmers, but will grow to 27% by 2050 if current trends continue, according to a study published today in the journal Global Change Biology.
“This research shows that the imbalance between nitrogen and phosphorus applications has the potential to further limit food production for a growing population in Africa” says Marijn van der Velde, a researcher now at the Joint Research Centre of the European Commission, who led the study while working at IIASA.
While nitrogen-based fertilizers can be produced by a process that extracts the element from the air, phosphorus must be mined from rock—and reserves are limited. That makes phosphorus fertilizers expensive, especially in the longer term.
“Farmers with limited money are more likely to buy and have access to cheaper nitrogen-based fertilizers,” says van der Velde. “While this might work in the short term, in the longer term it has a negative effect on crop growth as soil nutrients become more imbalanced.”
As farmers use fertilizers for their crops, nutrients such as nitrogen and phosphorus build up in the soil, providing a reserve of nutrients that plants need to grow. But fertilizer use remains very low in Africa, and to increase crop production, it is widely recognized that farmers must increase their fertilizer use. And while nitrogen-based fertilizer usage has begun to increase in Africa in the last 10 years, the application of phosphorus to cropland has not kept pace, leading to a growing imbalance between nitrogen and phosphorus levels in soil. The new study shows that increases in nitrogen and phosphorus inputs must happen in a way that provides crops with the balanced nutrient input they need.
The study used data from Food and Agriculture Organization (FAO) crop trials as well as an established EPIC large-scale crop model to estimate how the imbalance affects current and future crop yields.
“Previous research has looked at these effects on a field and local scale, but this is the first study to do so at the continental scale,” says IIASA researcher Christian Folberth, who also worked on the study.
In order to make optimal use of current nitrogen inputs, the researchers estimated that phosphorus applications would need to increase 2.3-fold. To close yield gaps nitrogen applications would have to increase 5-fold. Phosphorus applications would have to increase nearly 12-fold from 2.2 to 25.9 kg per hectare.
But because of the cost of phosphorus, that remains a challenge. ”While much of the remaining phosphorus reserves are found in Morocco, on the African continent, we need to find better ways for African farmers to access this precious resource” says van der Velde.
The global phosphorus cycle is, besides nitrogen, also increasingly growing out of balance with carbon, the subject of another recent paper by the same group of researchers and a new European Research Council grant for continued research by IIASA and an international team of scientists.
“The change in the stoichiometry of nitrogen and carbon from rising atmospheric CO2 concentrations relative to phosphorus has no equivalent in the Earth’s history and the impacts will go beyond the agricultural sector.” says van der Velde.Reference
ContactsMarijn van der Velde
Katherine Leitzell | idw
When a fish becomes fluid
17.12.2018 | Institute of Science and Technology Austria
Some brain tumors may respond to immunotherapy, new study suggests
11.12.2018 | Columbia University Irving Medical Center
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
18.12.2018 | Materials Sciences
18.12.2018 | Physics and Astronomy
18.12.2018 | Physics and Astronomy