In the race to feed a growing population, it is important to consider sustainability. University of Illinois researchers are promoting the practice of agroforestry—the intentional planting of trees and shrubs with crops or livestock—to achieve sustainability goals. A number of practical and policy challenges have prevented adoption of agroforestry practices on a large scale in the U.S. If adopted more widely, agroforestry could benefit wildlife, soil and water quality, and the global climate.
Feeding the world’s burgeoning population is a major challenge for agricultural scientists and agribusinesses, who are busy developing higher-yielding crop varieties. Yet University of Illinois researchers stress that we should not overlook sustainability in the frenzy to achieve production goals.
More than a third of the global land area is currently in food production. This figure is likely to expand, leading to deforestation, habitat loss, and weakening of essential ecosystem services, according to U of I agroecologist Sarah Taylor Lovell and graduate student Matt Wilson. To address these and other problems, they are promoting an unconventional solution: agroforestry.
Agroforestry is the intentional combination of trees and shrubs with crops or livestock. Or, as Wilson simply puts it, “You stick trees or shrubs in other stuff.”
The researchers describe five agroforestry practices:
- Alley cropping: field crops planted between rows of trees.
- Silvopasture: trees added to pasture systems.
- Riparian buffers: trees planted between field edges and river edges.
- Windbreaks: trees planted adjacent to planted fields and perpendicular to the prevailing wind pattern.
- Forest farming: harvest or cultivation of products—such as mushrooms, ginseng, or ornamental wood—in established forests.
Each of the five practices can benefit conventional and organic agroecosystems in similar ways. Woody plants can provide habitat for beneficial wildlife, prevent soil erosion, sequester atmospheric carbon, and absorb nutrient runoff while providing farmers with additional streams of income in the form of lumber or specialty products like nuts or berries. Each specific practice also provides unique benefits. For example, trees added to pasture landscapes provide shade to grazing livestock.
Farmers might be concerned about the trees casting too much shade on crops, but it is simply a matter of choosing the right complement of species. For example, the combination of winter wheat and walnut trees in an alley cropping system works well.
“Winter wheat grows in the late winter or early spring, but the walnut doesn’t leaf out until late spring,” Wilson explains. “So, when you mix the two together, you’ve got the benefit of having two crops growing in different parts of the year.”
Lovell adds, “The grain crop growing near the trees can actually force the trees to grow deeper roots. This can benefit individual trees because the root zone they’re forced to occupy gives them greater access to water.”
European farmers are ahead of their U.S. counterparts in terms of their adoption of agroforestry practices. “It’s very common in Europe. A lot of farmers are already doing hedgerows, which are similar to windbreaks, as part of their agroforestry systems, and even more integrated systems are fairly common,” Lovell says.
Wilson suggests that there are cultural barriers to adopting agroforestry practices in the U.S. “We’ve had some farmers share sentiments like, ‘why should I plant trees? My grandpa spent his whole life tearing trees out so he could put crops in.’ There’s definitely some perception that trees are not good in a farm landscape. Trying to overcome that has been a challenge,” he says.
Another obstacle in the U.S. is a policy mindset that treats production and conservation as completely separate functions of the land. For example, farmers are prohibited from harvesting or selling products from land designated for conservation, as in the USDA’s Conservation Reserve Program. There are USDA programs that support certain agroforestry practices such as wind breaks, but government support for more integrated practices is generally lacking. That’s why Lovell’s team is advocating for farmers to utilize marginal land.
“We are working with farmers to identify lands that are less productive, sensitive, or marginal, and suggesting those as the places to start transitioning,” Lovell explains. Or, she suggests, farmers could plant young “edibles” (trees and shrubs bearing fruit or nuts) in a CRP easement. By the time the CRP lease expires in 10 to 15 years, the trees would be mature, bearing edible—and potentially profitable—products.
The long timeframe needed for trees to establish and mature may discourage some farmers, but the researchers offer a strategy for the transition period. In an alley cropping system with hazelnut and chestnut trees, for example, they suggest growing edible shrubs and pasture between rows. Farmers can expect to start harvesting and selling hay almost immediately, and will start seeing fruit production from the shrubs within a couple of years. Eight to ten years after establishment, trees will begin producing nuts.
“We’re looking at economic strategies to maximize profit from the very beginning,” Lovell says.
Despite the challenges, the researchers insist the environmental benefits are worth the trouble. “If you have trees in a system, you’re holding soil, preventing runoff, and ameliorating greenhouse gas emissions. At the same time, you are getting a harvestable product. This combination of environmental services and agricultural production makes agroforestry an exciting opportunity to both feed the world and save the planet,” Wilson says.
The article, “Agroforestry—The next step in sustainable and resilient agriculture,” is published in Sustainability. The research was supported by the Jonathan Baldwin Turner Fellowship though the Department of Crop Sciences at the University of Illinois. The full text of the article is freely available at the journal’s website.
For further information, please contact:
Lauren Quinn | AlphaGalileo
Kakao in Monokultur verträgt Trockenheit besser als Kakao in Mischsystemen
18.09.2017 | Georg-August-Universität Göttingen
Ultrasound sensors make forage harvesters more reliable
28.08.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy