Monday, 26 March 2012

One Quarter of World’s Agricultural Land ‘Highly Degraded’

Planetsave reports on a recently published UN Food and Agriculture Organisation (FAO) report which has concluded that 25% of all land is “highly degraded” making it unsuitable for agriculture. The report, ‘State of the World’s Land and Water Resources for Food and Agriculture’ calls for “sustainable intensification” of agricultural productivity on existing farmland.

The report compares current food production rates to those following the ‘Green Revolution’ (which introduced new technologies, fertilizers, pesticides and high-yield crops) during the fifty year period from 1961 through 2009. During this time, though agricultural land increased just 12%, the total agricultural food output increased a remarkable 150%. But that is not the case today where the rate of productivity in many areas is slowing, with some producing only half as much as was produced during the Green Revolution.

Friday, 23 March 2012

'Fertilizer Forecaster' aimed at improving water quality

The Gant Daily reports that Pennysylvania State University and an arm of the USDA have been awarded a grant of US$484,000 to develop a Fertiliser Forecaster, a web-based decision-support tool that producers can use before applying fertilizer to assess the risk of nutrients running off in surface water.

“Mandated nutrient-management plans are designed to provide guidance for farmers that can help them make prudent decisions,” said project director Patrick Drohan, assistant professor of pedology in Penn State’s College of Agricultural Sciences. “But these plans may not provide the day-to-day support required to make operational decisions — particularly when and where to apply nutrients in the short term,” he said. “These short-term decisions can make the difference between whether the nutrients impact water quality or are efficiently utilized by crops.”

Rainfall that infiltrates the soil on the heels of a broadcast fertilizer application is beneficial, Drohan explained, because it washes soluble nutrients into the soil where they can be used by crops. Conversely, rainfall events that generate runoff shortly after fertilizer applications can lead to significant nutrient loss from the site, ultimately polluting bodies of water, such as streams, rivers and the Chesapeake Bay.

“Our goal is to develop a research-driven support tool for nutrient management that identifies the relative probability of runoff or infiltrating events in Pennsylvania landscapes,” said project co-director Anthony Buda, research hydrologist with USDA-ARS. “This tool will support field-specific decisions by farmers on when and where to apply fertilizers and manures over 24-, 48- and 72-hour periods.”

Read more here.

The Wisconsin Department of Agriculture, Trade and Consumer Protection already runs a web-based system advising farmers on the risk of run-off. The Runoff Risk Advisory Forecast map shows day-to-day risk of runoff occurring across Wisconsin using National Weather Service forecast methods that consider precipitation, soil moisture, and individual basin characteristics. The maps are provided to help reduce the risk of runoff losses following nutrient/manure applications or other land management activities. The risk levels shown represent predictions for expected conditions across these large areas, not for specific fields within the basin. Have a look at the system here.

Tuesday, 20 March 2012

The State of Soil in Europe

The recent publication of The State of Soil in Europe by the European Environment Agency (part of the European Commission) went largely unnoticed, but carries some interesting, and quite alarming, statistics.

Greenfacts reports that eight major aspects of soil degradation in Europe have been identified: biodiversity decline, compaction, contamination, erosion, landslides, organic matter decline, salinisation and sealing . Further, acidification, desertification or biofuels production are other potential threats to soil integrity considered in this report. All these problems have considerable economic and environmental consequences and could eventually compromise food production. Poor land management, such as deforestation, overgrazing, construction activities and forest fires are among the main causes of this situation.

The Euro Forest Portal says that the report shows that the main soil degradation processes are accelerating in many parts of Europe, often as a result of human activities. It shows that soil resources in many parts of Europe are being overexploited, degraded and irreversibly lost. These trends are accelerated by inappropriate land management practices, industrial activities and land use changes.

Enterprise Europe London highlights some particularly disturbing statistics from the report: Between 1990 and 2006, at least 275 hectares of soil per day were permanently lost through soil sealing – the covering of fertile land by impermeable material – amounting to 1,000 km² per year, or an area the size of Cyprus every ten years. Soil erosion by water is estimated to affect 1.3 million km² in Europe, an area equivalent to 2.5 times the size of France. Soil degradation affects our capacity to produce food, prevent droughts and flooding, stop biodiversity loss, and tackle climate change.

It quotes Environment Commissioner Janez Potočnik: "These reports highlight the importance of preserving European soils if we are to safeguard supplies of quality food and clean groundwater, healthy recreational spaces, and lower greenhouse gas emissions. We need to use the resources from our soils more sustainably. The best way to do this would be through a common approach across the EU. The Commission has put legislative proposals on the table, and I hope our new reports will help Council and Parliament move towards action."

Download the full report here.

Monday, 19 March 2012

Fertility wisdom challenged for no-till cereals

The Australian journal, The Land, reports that anecdotal evidence of soil nitrogen consistently being above expected levels in no-till, cereal-on-cereal farming systems raises questions over the established wisdom of how nitrogen replenishment works, according to Western Australian consultant and no-till advocate Bill Crabtree.

Mr Crabtree said no-till farmers who, for a range of reasons, had been unable to include legumes in their rotations were finding that soil nitrogen levels were not depleting as fast as expected. He said he’d observed the phenomenon in no-till farming systems internationally, including Western Australia where many producers had been forced to drop lupins from their rotations because of the crop’s poor yields and returns and the difficulty of managing weeds like radish and ryegrass.

“I have found that people who have kept all their stubble and not grown a legume in the system have more nitrogen in their soil than what we would expect them to have,” he said. “A lot of people are now growing wheat/wheat/wheat/canola then wheat/wheat/wheat and we are not finding it crashing. In fact we are measuring good units of nitrogen in the soil.

“Some people will say they are getting the nitrogen out of the straw, but if the organic carbon is not going down across 10 years and you are harvesting 75 units of nitrogen (in the grain) every year and you are only putting on 25 units (in fertiliser) every year, then it has to be coming from somewhere.”

Read the full article here.

Wednesday, 14 March 2012

Using biochar to boost soil moisture

Science Codex reports that scientists at the U.S. Department of Agriculture (USDA) are leading the way in learning more about biochar, the charred biomass created from wood, other plant material, and manure. Their research has shown that differetn biochars produced from a range of feedstocks have varying characteristics, including in relation to moisture and nutrient retention.

For example, biochars produced from switchgrass and hardwoods produced via high-temperature pyrolysis increased soil moisture storage, but only by 3 to 6 percent above the control soil sample. Biochars produced at higher temperatures also increased soil pH levels, and biochar made from poultry litter greatly increased soil levels of available phosphorus and sodium. Given their results, the team believes that agricultural producers could someday select feedstocks and pyrolysis processes to make "designer" biochars with characteristics that target specific deficiencies in soil types.

Read the full article here.

Tuesday, 13 March 2012

Phosphorus and groundwater: Scientists establish links between agricultural use and transport to streams

Waterworld reports that US scientists have, for the first time, demonstrated how aquifer composition can affect how excessive levels of phosphorous (an essential nutrient contained in fertilizers) can be carried from fertilized agricultural fields via groundwater to streams and waterways. This finding will allow for more informed management of agriculture, ecosystem, and human water needs.

Nutrient transport from agricultural fields is one of the most serious environmental problems throughout the world because it can cause adverse effects on aquatic ecosystems and/or drinking water supplies. Excess phosphorus can stimulate algal growth in streams and lakes (eutrophication), leading to decreased levels of dissolved oxygen and the death of sensitive organisms including fish, or can cause changes in the types of algae that are present. Some forms of algae can also release toxins that can negatively impact human health.

"While the widespread use of fertilizer has increased crop yields, excessive application is not only wasteful, but it can also be harmful to water quality, fish, and human health," said US Geological Survey (USGS) director Marcia McNutt. "New USGS science demonstrates how and when excess phosphorous is moving underground from fields to streams, and what underground conditions can mitigate nutrient transport."


Monday, 5 March 2012

Crop sensors outdo farmers at choosing nitrogen rates

Brightsurf.com reports what Euopean farmers have known for years - that crop sensors are better at identifying what nitrogen (N) rates should be used for a particular crop than those chosen by farmers, and that their use can also reduce waste and cut costs. Trials conducted in Missouri showed that applying N at rates recommended by sensors increased maize grain yields by an average of two bushels per acre (around 125kg/ha) and in some cases up to 8 bushels an acre (c.600kg/ha). The same trials also showed that using these sensors reduced N wastage (i.e. N applied but not used by the crop) by around 25%.

The study's leader, Peter Scharf, a University of Missouri extension agronomist, said that although optimal N rates can vary substantially within and between fields, most U.S. corn growers still apply the same rates to entire fields or even entire farms.   Many farmers in Missouri and elsewhere also spread N fertilizer months before planting, often the November before, increasing the chanvces of N being leached by winter rains and lost from the soil.

The sensors take advantage of what farmers know already from experience and common sense, Scharf says: Crops with enough N are darker green and taller, while N-deficient crops are lighter and shorter.  After developing a technique for translating sensor output into a suitable N rate within a few seconds - work that was published in 2009 - Scharf and his collaborators began taking the technology to farms.

Despite the sensors' benefits, however, "the adoption numbers are still quite small," Scharf says.  Complete systems currently range in price from $10,500 to $16,500, and learning to use them involves time and expense, as well. Still, these aren't the main hurdles to wider adoption, he adds.  The bigger one is getting farmers to side-dress N during the growing season, rather than fertilizing in spring before planting or even the fall before.

Read more here.

Friday, 2 March 2012

Soil conservation in the US: the highs and lows

Soil conservation has hit the news in the United States in recent days. The Environmental Working Group reports that most farmers support the long-standing conservation compact that has helped protect the rich soil and clean water that sustain food, farming and public health. This was the 1985 Farm Bill, under which growers agreed to keep soil from washing away and chemicals out of waterways in return for generous taxpayer support. Seven polls taken in the last 30 years show that a solid majority of farmers believe that bargain is a fair one.

Politico reports that EWG's report also finds that early progress reducing soil erosion has stalled and in some states like Iowa, losses have even increased — all in a time of record farm income. “The gold rush in farm country is putting unprecedented pressure on our soil and water,” is the report’s opening salvo. “Now more than ever, the nation needs a reinvigorated and strengthened conservation compact.”

EWG reports that that high prices, intense competition for farmland leases and ethanol mandates have put unprecedented pressure on land and water. As a result, the historic gains in soil conservation the compact achieved are being lost.

“Conservation is once again being pushed to the back seat – the very situation that led to the compact in the first place,” said EWG Senior Vice President Craig Cox. “We need to reinvigorate the compact just to keep things from getting worse, let alone make long-overdue progress on pollution problems that have gone unchecked for decades.”

In the negotiations over a 2012 farm bill, agribusiness lobbyists are pushing their allies in Congress to gut the conservation compact entirely, with dire consequences for the environment and public health.

On the same day that the EWG report was published, the Times and Demorcat reported that Agriculture Secretary Tom Vilsack has announced a new conservation initiative to protect up to 750,000 acres of the nation’s most highly erodible croplands. The new initiative will assist producers with targeting their most highly erodible cropland by enabling them to plant wildlife-friendly, long-term cover through the Conservation Reserve Program.

Europe's dependence on foreign soil deepens

German news website DW.de reports Friends of the Earth claims that Europe is more dependent on land from abroad than any other continent. In a report measuring "land footprints," the group warns that Europe's need for 1.5 times its land is untenable. Analysts discovered that when foreign territory was included, average land utilization in Europe equaled 1.3 hectares per person, compared to less than 0.4 hectares of land in countries like China and India.

Campaigners say the dramatic findings once again expose the true extent to which Europe's consumption levels are unsustainable.

"Europe is more dependent on 'imported land' than any other region in the world," said Kenneth Richter from Friends of the Earth. "This has a significant impact on the ability of people in poor countries, where this land is taken away from food production, to feed themselves," he told Deutsche Welle.

Germany and the United Kingdom were singled out as having the greatest demand, with approximately 70 million hectares of foreign territory used - almost two-and-a-half times the size of Germany. That's in addition to utilizing about 10 million hectares of domestic land. Researchers point to the large-scale import of animal feed -particularly soy - from South America, which is required for meat production in both countries.

Read more here.

Thursday, 1 March 2012

From Tropics to Poles: Study Reveals Diversity of Life in Soils

Brightsurf.com reports on a study published in the journal Proceedings of the National Academy of Sciences finds that microscopic animals that live in soils are as diverse in the tropical forests of Costa Rica as they are in the arid grasslands of Kenya, or the tundra and boreal forests of Alaska and Sweden.

The Brightsurf.com article refers to the accepted wisdom of a wider range of species being found above ground at the equator than at the Earth's poles. But this study proves for the first time that the same rules don't apply to the nematodes, mites and springtails living underground.

Soil samples taken from a range of habitats in 11 sites around the world each hosted a diversity of soil organisms, identified through DNA testing. Each of these ecosystems was found to be unique with its own soil animals – illustrating an "amazing diversity of species" that had never been discovered before.

But 96% of identified soil animals were found at only a single location, suggesting that most soil animals have restricted distributions, or in other words, they are endemic. This challenges the long-held view that these smaller animals are widely distributed. However, unlike most above-ground organisms, there was no indication that latitude made a difference in soil animal diversity. In fact, sites with greater aboveground biodiversity appeared to have lower diversity beneath in soils.

Read more here.