Although most of the world's biodiversity is below ground, surprisingly little is known about how it affects ecosystems or how it will be affected by climate change. A new study demonstrates that soil bacteria and the richness of animal species belowground play a key role in regulating a whole suite of ecosystem functions on Earth. The authors call for far more attention to this overlooked world of worms, bugs and bacteria in the soil.
Ecosystem functions such as carbon storage and the availability of nutrients are linked to the bugs, bacteria and other microscopic organisms that occur in the soil. In fact, as much as 32% of the variation seen in ecosystem functions can be explained by the biodiversity in the soil. In comparison, plant biodiversity accounts for 42%. That is the conclusions of a new study published in Nature Communications led by Peking University and the Center for Macroecology, Evolution and Climate at the University of Copenhagen.
Read more at Biodiversity Belowground Is Just As Important As Aboveground
Large areas of farmland in the east of England could become unprofitable within a generation as soil erosion and degradation make it less productive, according to the Government’s official climate change advisory group.
The Committee on Climate Change (CCC) report says the UK will be in danger of producing less food in the coming decades, when it should be producing more.
The degradation is the result of increasingly intense farming practices, with deep plowing, rapid crop-rotation and ever-larger fields free of trees allowing the wind and rain to carry away the top layer of soil, according to the report. Farmland around the East Anglian Fens could become less productive and less profitable, forcing the country to increase food imports at a time of growing global demand and rising prices, it says.
Britain’s soil quality has already been damaged. The country has lost 84 per cent of its fertile topsoil since 1850, with the erosion continuing at a rate of 1cm to 3cm a year.
Farmers have been able to improve yields through technological advances, but it is only a matter of time before productivity decreases, experts say. “Soil is a very important resource which we have been very carefree with. At the moment we are treating our agricultural soils as though they are a mined resource – that we can deplete – rather than a stewarded resource that we have to maintain for the long-term future,” said Lord Krebs, chairman of the CCC’s adaptation sub-committee.
And climate change is set to make matters worse by increasing temperatures and water shortages that make the soil dustier, as well as the frequency of heavy rainstorms, which wash it away.
“The most fertile topsoils in the east of England – where 25 per cent of our potatoes and 30 per cent of our vegetables are grown – could be lost within a generation,” said Lord Krebs.
“Soil is a very important resource which we have been very carefree with. At the moment we are treating our agricultural soils as though they are a mined resource – that we can deplete – rather than a stewarded resource that we have to maintain for the long-term future,” said Lord Krebs, chairman of the CCC’s adaptation sub-committee.
And climate change is set to make matters worse by increasing temperatures and water shortages that make the soil dustier, as well as the frequency of heavy rainstorms, which wash it away.
“The most fertile topsoils in the east of England – where 25 per cent of our potatoes and 30 per cent of our vegetables are grown – could be lost within a generation,” said Lord Krebs.
Read original article at Soil Erosion a Major Threat to Britain'S Food Supply, Says Government Advisory Group
Climate change may expand suitable cropland, particularly in the Northern high latitudes, but tropical regions may becoming decreasingly suitable, according to a study published September 17, 2014 in the open-access journal PLOS ONE by Florian Zabel from Ludwig Maximilians University, Germany and colleagues.
Most of the Earth's accessible agricultural land are already under cultivation. Ecological factors such as climate, soil quality, water supply and topography determine the suitability of land for agriculture. Climate change may impact global agriculture, but some regions may benefit from it. In a new study, researchers focused on the probable impact of climate change on the supply of land suitable for the cultivation of the 16 major food and energy crops worldwide, including staples such as maize, rice, soybeans and wheat. They simulated the impact of climate change on agricultural production over the course of the 21st century and found that two-thirds of all land potentially suitable for agricultural use is already under cultivation.
The results indicate that climate change may expand the supply of cropland in the high latitudes of the Northern hemisphere, including Canada, Russia, China, over the next 100 years. However, in the absence of adaptation measures such as increased irrigation, the simulation projects a significant loss of suitable agricultural land in Mediterranean regions and in parts of Sub-Saharan Africa. The land suitable for agricultural would be about 54 million km2 -- and of this, 91% is already under cultivation. "Much of the additional area is, however, at best only moderately suited to agricultural use, so the proportion of highly fertile land used for crop production will decrease," says Zabel. Moreover, in the tropical regions of Brazil, Asia and Central Africa, climate change will significantly reduce the chance of obtaining multiple harvests per year.
"In the context of current projections, which predict that the demand for food will double by the year 2050 as the result of population increase, our results are quite alarming. In addition, one must consider the prospect of increased pressure on land resources for the cultivation of forage crops and animal feed owing to rising demand for meat, and the expansion of land use for the production of bioenergy," says Zabel.
The Future of Global Agriculture May Include New Land, Fewer Harvests
Two down, one to go. Researchers have completed the second of three major steps needed to turbocharge photosynthesis in crops such as wheat and rice, something that could boost yields by around 36 to 60 percent for many plants. Because it’s more efficient, the new photosynthesis method could also cut the amount of fertilizer and water needed to grow food.
Researchers at Cornell University and Rothamsted Research in the United Kingdom successfully transplanted genes from a type of bacteria—called cyanobacteria—into tobacco plants, which are often used in research. The genes allow the plant to produce a more efficient enzyme for converting carbon dioxide from the atmosphere into sugars and other carbohydrates. The results were published Wednesday in the journal Nature.
Scientists have long known that some plants are much more efficient at turning carbon dioxide into sugar than other plants. These fast-growing plants—called C4 plants—include corn and many types of weeds. But 75 percent of the world’s crops (known as C3 plants) use a slower and less efficient form of photosynthesis. Researchers have been attempting for a long time to change some C3 plants—including wheat, rice, and potatoes—into C4 plants. The approach has been given a boost lately by novel high-precision gene-editing technologies that are being applied to the C4 Rice Project (see “Why We Will Need Genetically Modified Foods”).
The Cornell and Rothamsted researchers took a simpler approach. Rather than attempting to convert a C3 plant into a C4 plant by changing its anatomy and adding new cell types and structures, the researchers modified components of existing cells. “If you can have a simpler mechanism that doesn’t require anatomical changes, that’s pretty darn good,” says Daniel Voytas, director of the Center for Genome Engineering at the University of Minnesota.
Turbocharging Photosynthesis to Feed the World
INRA research scientists in Dijon have shown that the ability of soils to eliminate N2O can mainly be explained by the diversity and abundance of a new group of micro-organisms that are capable of transforming it into atmospheric nitrogen (N2).
Nitrous oxide (N2O) is a potent greenhouse gas that is also responsible for destroying the ozone layer. INRA research scientists in Dijon have shown that the ability of soils to eliminate N2O can mainly be explained by the diversity and abundance of a new group of micro-organisms that are capable of transforming it into atmospheric nitrogen (N2). These results, published in Nature Climate Change in September 2014, underline the importance of microbial diversity to the functioning of soils and the services they deliver.
Nitrous oxide (N2O) is one of the principal greenhouse gases, alongside carbon dioxide (CO2) and methane (CH4); it is also responsible for destruction of the ozone layer. Terrestrial ecosystems contribute to about 70% of N2O emissions, at least 45% being linked to the nitrogen-containing products found in agricultural soils (fertilisers, slurry, manure, crop residues, etc.). "In order to lower emissions of N2O and develop more environmentally-friendly agriculture, it is important to understand the processes involved not only in its production but in its elimination," explain the scientists. This elimination can be achieved by micro-organisms living in the soil that are able to reduce N2O into nitrogen (N2), the gas that makes up around four-fifths of the air we breathe and which has no impact on the environment.
Greenhouse Gases: New Group of Soil Micro-Organisms Can Contribute to Their Elimination
Ultimately, algae blooms are caused by excess phosphorus in the water that provides the algae with the fertilizer it needs to grow exponentially, given enough sun and warm enough water temperatures. But the source of that phosphorus can vary.
From the 1960s to the 1980s, said Glenn Benoy, a senior water quality specialist and science adviser with the International Joint Commission. the main source of phosphorus was sewage plants. The algae problem was considered so serious that communities on the shores of the lake poured billions of dollars into sewage infrastructure upgrades and implemented laws banning phosphorus in laundry detergents.
This time the main problems are thought to be ones that governments have much less direct control over. To some extent, they include the application of fertilizers to lawns and golf courses, growing expanses of pavement in urban areas that cause water to drain more quickly into waterways without being filtered by vegetation, and invasive zebra mussels that release extra nutrients into the water as they feed. But those aren't thought to be the biggest cause.
"We think farming is the major culprit behind the current levels of phosphorus that's in runoff and the phosphorus loads that are getting dumped into the western basin of Lake Erie," Benoy told CBC News.
The commission's report suggested that changes to farming practices were largely to blame for recent blooms.
"The main changes that are responsible have to do with intensification of farming – getting more out of the land than we did historically," Benoy said, adding that that includes things like:
- More livestock farming and greater application of their waste to fields.
- Higher application of fertilizers in general.
- An increase in corn farming in the U.S. Midwest, partly to meet a demand for ethanol fuel.
Corn is demanding when it comes to fertilizers," Benoy said. In fact, there's so much corn being farmed in some parts of the region that it's not possible to deliver the amount of fertilizer they require in the spring, said Ivan O'Halloran, an associate professor at the University of Guelph's campus in Ridgetown, Ont., who studies soil fertility and nutrient use.
As a result, companies sometimes offer discounts to farmers who buy and apply their fertilizer to the surface of their fields in the fall – a practice that appears to significantly increase the rate at which it gets washed into local waterways.
The algae problem in Lake Erie that fouled the water that hundreds of thousands of people rely on for drinking, cooking and bathing last week was thought to have been successfully eliminated in the 1980s. Farming is the main culprit today, and climate change has become an "aggravating factor."
Lake Erie's Algae Explosion Blamed on Farmers
