Diverse plant communities are more successful and enable higher crop yields than pure monocultures, a European research team headed by ecologists from the University of Zurich has discovered. The scientists are convinced that the cultivation of crop mixtures in agriculture and forestry will play a key role in food safety in the future.
Although monocultures can be cultivated efficiently, they are anything but sustainable: environmental damage to soil and water caused by monoculture cultivation is becoming increasingly evident. Despite their disadvantages, however, monocultures remain the principal crop form and are regarded as the sole possibility of achieving higher yields in plant production – quite wrongfully, finds Bernhard Schmid, an ecology professor at the University of Zurich, who advocates a novel form of agriculture and forestry.
After all, a new study carried out by PhD student Debra Zuppinger Dingley reveals that in grassland plants the yields of diverse plant communities are larger than those of monocultures.
Schmid sees “an opportunity for the future of nutrition for humankind in the untapped potential of biodiversity” – a promising prospect as the OECD and the United Nations’ Food and Agriculture Organization (FAO) are giving off worrying signals: Both organizations predict that agricultural productivity will rise less steeply in future than has been the case thus far. With a global population that is also on the increase, this would signify a decline in food safety.
Diverse plant communities use resources more effectively
In a 10-year study, a team of researchers from Switzerland, Germany and the Netherlands headed by Schmid examined the yields from grassland plants which they had cultivated in monocultures or mixed plant communities. Surprisingly, the latter proved to be more productive than the monocultures. “Due to their diversity, plant species in communities occupy all the niches available in an ecosystem. This enables them to use soil nutrients, light and water far more effectively than monocultures, which ultimately leads to greater yields,” explains Dan Flynn, a postdoc in Schmid’s group.
Another advantage: There is less pressure from parasites on plants in diverse communities than on those in monocultures. In other words, a parasite can spread less effectively as it is unable to find its special host plant as easily in a biodiverse plant world. The different plant species thus act as protective shields for each other. This mutual protection within the group enables individual plants to invest the resources available into growth and the production of offspring instead of pest control. “Diversity offers protection against pests and is a prerequisite for higher yields in plant communities,” says Schmid.
Plant species evolve with each other
Moreover, the researchers discovered that species adapt to their plant communities in the time of a few generations. This so-called short-term evolution leads to a continued increase of crop yield in mixtures – a possibility that, according to Schmid, was unexpected in both basic research and plant cultivation. In this adaptation process, the various species specialize in their strengths and thus improve the complementary utilization of resources throughout the plant community by a process called character displacement. Grasses, for instance, develop thicker leaves, which are able to utilize the direct sunlight in the upper layer of a meadow while clover species sprout larger but thinner leaves to absorb the weaker light close to the ground more effectively.
Paving the way for sustainable agriculture and forestry
Today, biodiversity is primarily associated with pure conservation, the preservation of species and genetic diversity. “The research results reveal that diversity enables the functionality of the ecosystems to be stabilized at a high level in the course of time and in different environments,” concludes Schmid. He is convinced that the results published in the science journal Nature, coupled with the findings from his earlier research projects, can trigger a paradigm shift in agriculture in the long run. After all, the positive effects of mixed crops are not just evident in plant communities like meadows and forests, but also in the mixed cultivation of different varieties or genotypes of a single crop such as wheat.
“Plant breeding and cultivation methods should therefore be geared towards mixtures instead of improving the output of monocultures,” says the ecologist from UZH. The fact that more sustainable farming will also be promoted in the process because mixtures require less pest control and utilize fertilizers more effectively is a welcome bonus.
Debra Zuppinger-Dingley, Bernhard Schmid, Jana S. Petermann, Varuna Yadav, Gerlinde B. De Deyn, Dan F. B. Flynn. Selection for niche differentiation in plant communities increases biodiversity effects. doi: 10.1038/nature13869
Simon L. Zeller, Olena Kalinina, Dan F. B. Flynn, Bernhard Schmid, Mixtures of genetically modified wheat lines outperform monocultures. Ecological Applications, 22(6), 2012, pp. 1817–1826
Prof. Bernhard Schmid
Institute of Evolutionary Biology and Environmental Studies
University of Zurich
Tel.: +41 79 681 99 36
Nathalie Huber | Universität Zürich
Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München
Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences