Crops, number, globally, sustainable, agriculture dominating. A new study finds that globally we’re growing more of the same kinds of crops, and this presents major challenges for agricultural sustainability on a global scale.
The study, done by an international team of researchers led by the University of Toronto assistant professor Adam Martin, used data from the U.N.’s Food and Agricultural Organization (FAO) to look at which crops were grown where on large-scale industrial farmlands from 1961 to 2014.
They found that within regions crop diversity has actually increased — in North America for example, 93 different crops are now grown compared to 80 back in the 1960s. The problem, Martin says, is that on a global scale we’re now seeing more of the same kinds of crops being grown on much larger scales.
In other words, large industrial-sized farms in Asia, Europe, North and South America are beginning to look the same.
“What we’re seeing is large monocultures of crops that are commercially valuable being grown in greater numbers around the world,” says Martin, who is an ecologist in the Department of Physical and Environmental Sciences at the University of Toronto Scarborough.
“So large industrial farms are often growing one crop species, which are usually just a single genotype, across thousands of hectares of land.”
Soybeans, wheat, rice, and corn are prime examples. These four crops alone occupy just shy of 50 percent of the world’s entire agricultural lands, while the remaining 152 crops cover the rest.
It’s widely assumed that the biggest change in global agricultural diversity took part during the so-called Columbia exchange of the 15th and 16th centuries where commercially important plant species were being transported to different parts of the world.
But the authors found that in the 1980s there was a massive increase in global crop diversity as different types of crops were being grown in new places on an industrial scale for the first time. By the 1990s that diversity flattened out, and what’s happened since is that diversity across regions began to decline.
The lack of genetic diversity within individual crops is pretty obvious, says Martin. For example, in North America, six individual genotypes comprise about 50 percent of all maize (corn) crops.
This decline in global crop diversity is an issue for a number of reasons. For one, it affects regional food sovereignty. “If regional crop diversity is threatened, it really cuts into people’s ability to eat or afford food that is culturally significant to them,” says Martin.
There is also an ecological issue; think potato famine, but on a global scale. Martin says if there’s increasing dominance by a few genetic lineages of crops, then the global agricultural system becomes increasingly susceptible to pests or diseases. He points to a deadly fungus that continues to devastate banana plantations around the world as an example.
He hopes to apply the same global-scale analysis to look at national patterns of crop diversity as a next step for the research. Martin adds that there’s a policy angle to consider, since government decisions that favor growing certain kinds of crops may contribute to a lack of diversity.
“It will be important to look at what governments are doing to promote more different types of crops being grown, or at a policy-level, are they favoring farms to grow certain types of cash crops,” he says.
The practice of agriculture is also known as “farming”, while scientists, inventors, and others devoted to improving farming methods and implements are also said to be engaged in agriculture.
Subsistence farming, who farms a small area with limited resource inputs, and produces only enough food to meet the needs of his/her family.
At the other end is commercial intensive agriculture, including industrial agriculture.
Such farming involves large fields and/or numbers of animals, large resource inputs (pesticides, fertilizers, etc.), and a high level of mechanization.
These operations generally attempt to maximize financial income from grain, produce, or livestock.
Modern agriculture extends well beyond the traditional production of food for humans and animal feeds.
Other agricultural production goods include timber, fertilizers, animal hides, leather, industrial chemicals (starch, sugar, alcohols and resins), fibers (cotton, wool, hemp, silk and flax), fuels (methane from biomass, ethanol, biodiesel), cut flowers, ornamental and nursery plants, tropical fish and birds for the pet trade, and both legal and illegal drugs (biopharmaceuticals, tobacco, marijuana, opium, cocaine).
The 20th Century saw massive changes in agricultural practice, particularly in agricultural chemistry.
Agricultural chemistry includes the application of chemical fertilizer, chemical insecticides, and chemical fungicides, soil makeup, analysis of agricultural products, and nutritional needs of farm animals.
Beginning in the Western world, the green revolution spread many of these changes to farms throughout the world, with varying success.
Other recent changes in agriculture include hydroponics, plant breeding, hybridization, gene manipulation, better management of soil nutrients, and improved weed control.
Genetic engineering has yielded crops that have capabilities beyond those of naturally occurring plants, such as higher yields and disease resistance.
Modified seeds germinate faster, and thus can be grown in an extended growing area.
Genetic engineering of plants has proven controversial, particularly in the case of herbicide-resistant plants.
As of 2006, an estimated 36 percent of the world’s workers are employed in agriculture (down from 42% in 1996), making it by far the most common occupation.
However, the relative significance of farming has dropped steadily since the beginning of industrialization, and in 2006 – for the first time in history – the services sector overtook agriculture as the economic sector employing the most people worldwide.
Also, agricultural production accounts for less than five percent of the gross world product (an aggregate of all gross domestic products).
Daily fluctuating rhythms were first discovered in plants in 1729 by measuring leaf-movement rhythms in Mimosas. Now research at the Earlham Institute, led by Ph.D. Student Hannah Rees, has ‘shed light’ on how they work in different crop plant species.
Importantly, Hannah has developed a robust method to accurately measure plant clocks in wheat and Brassica using naturally occurring ‘delayed fluorescence’, which will be very useful for research into improving crops for the future.
Delayed fluorescence is light that is emitted by plants after being illuminated, which persists for a long time when placed in the dark.* The paper, published in Plant Methods, sheds light on what makes wheat ‘tick’, and how plants show signs of aging.
The circadian clock in people is well known, and well understood — such as experiencing jet lag and sleep-deprivation after traveling between different time zones. Even the changing of the clock by one hour either side of summer can put us out of sync, our body clocks taking a few days to re-attune.
Plants, too, suffer similar consequences of changing light conditions, which are now easier to investigate thanks to the recent work at EI. Among the findings, the in-built circadian clock keeps ticking along in Brassica plants in 24-hour light, whereas in wheat the clock oscillates better under constant darkness.
More interestingly still, it appears that in both types of plants, the circadian clock oscillates faster as the plant ages — which is true of even older leaves and younger leaves on a single plant.
Hannah has developed a robust method of measuring daily patterns in plants such as wheat, which has proven difficult previously as most methods have relied on using genetic modification — a technique that isn’t very easy to pull off in wheat. Other techniques looking at leaf movement only work in dicots (plants with two seed leaves), whereas wheat is a monocot (a plant with one seed leaf, like grasses and lilies).
The technique works by measuring delayed fluorescence from photosystem II, which as the name implies, is crucial for photosynthesis. The activity of photosystem II oscillates in a 24-hour window, which is very useful in organisms that rely on the sun upon for energy.
This technique will allow researchers to detect differences between circadian rhythms in crops currently being grown for food and help them work out if the rhythm fits the environment in which it is being grown. Crops grown on the equator may need different rhythms to plants grown near the poles because of differences in day-length. Plants with circadian clocks in sync with the natural environment are healthier and produce higher yields.
Lead author Hannah Rees, said: “We’re really thrilled to lead the first study using delayed fluorescence (light emission) as a tool for enhancing crop plants, focusing on the useful insight we’ve gained on the differences between how the clock rhythms work in Brassica and wheat. Read Here
“The fact that the clock speeds up as the plant gets older is also really amazing and our next question is why this might happen? Is there a biological advantage for having a ‘teenage’ clock and an ‘elderly clock’? We hope our work will help to improve crop yields by allowing breeders to select crops with circadian clocks matched for optimal growth in certain regions of the world.”