Friday, 29 June 2012

The clean-up begins on China's dirty secret – soil pollution

The Guardian reports on how China is putting considerable effort into cleaning up its contaminated soils which threaten agriculture and which are likely to prove a bigger long-term problem than air and water pollution.   According to the newspaper, nowhere is the global push to restore degraded land likely to be more important, complex and expensive than in China, where vast swaths of the soil are contaminated by arsenic and heavy metals from mines and factories.

Zhou Jianmin, director of the China Soil Association, estimated that one-tenth of China's farmland was affected.  "The country, the government and the public should realise how serious the soil pollution is," he said.  "More areas are being affected, the degree of contamination is intensifying and the range of toxins is increasing."

The land – and food chain – are threatened by lead and heavy metals from factories and overuse of pesticides and fertilisers by farmers, with one recent report stating that pollution ruins almost 12bn kilograms of food production each year, causing economic losses of 20 billion yuan.

Huang Hongxiang, a researcher from the Institute of Agricultural Resources and Regional Planning, warned earlier this year that China needed to widen its focus from production volumes.  "If we don't improve the quality of farmland, but only depend on increasing investment and improving technology, then – regardless of whatever super rice, super wheat and other super quality crops we come up with – it will be difficult to guarantee the sustainable development of our nation's agriculture."

Read the full report here.

Thursday, 21 June 2012

Global warming threat seen in fertile soil of northeastern US forests reports how a study by the University of California at Irvine and other researchers has found that vast stores of carbon in U.S. forest soils could be released by rising global temperatures.  The findings are published in the online Proceedings of the National Academy of Sciences in Washington, D.C.

The scientists found that heating soil in Wisconsin and North Carolina woodlands by 10 and 20 degrees increased the release of carbon dioxide by up to eight times.  They showed for the first time that most carbon in topsoil is vulnerable to this warming effect.

"We found that decades-old carbon in surface soils is released to the atmosphere faster when temperatures become warmer," said lead author Francesca Hopkins, a doctoral researcher in UCI's Earth system science department.  "This suggests that soils could accelerate global warming through a vicious cycle in which man-made warming releases carbon from soils to the atmosphere, which, in turn, would warm the planet more."

Soil, which takes its rich, brown color from large amounts of carbon in decaying leaves and roots, stores more than twice as much of the element as does the atmosphere, according to United Nations reports.  Previously, it wasn't known whether carbon housed in soil for a decade or longer would be released faster under higher temperatures, because it's difficult to measure.  The team, using carbon isotopes, discovered that older soil carbon is indeed susceptible to warming.

Read the full report on here.

Wednesday, 13 June 2012

Roll up, roll up for India's first soil museum

The Times of India reports that India is expected to get its first soil museum, designed to showcase its rich soil and mineral resources as well as to promote awareness about conservation and protection of ecology.   The museum, planned for the state of Kerala, will have a huge collection of soil samples, intended to provide information on soil types and crops suitable to each type.

The Times reports that of the 11 major global soil categories classified by the USDA soil classification system, the south western state of Kerala is endowed with nine types, ranging from black alkaline soil to extreme acidic soil.   One benefit of the soil musem will be to help improve understanding of soils amongst farmers, many of whom lack first-hand information on the nature of soil and consequently use excess fertilizers, resulting in low margins and high costs.

"The museum will also have a mini theatre where documentaries related to soil conservation and protection will be screened daily.  This will help research scholars, school students, farmers and nature lovers," Dr P N Premachandran, director of soil survey and soil conservation department, said.   Experts said the state has unique soil patterns suitable for paddy and horticulture cultivation. "The black cotton soil in Palakkad is ideal for vegetable cultivation and gives high yield. Similarly, the marshy soil where Pokkali paddy cultivation is done has rich micro-nutrients and farmers need not add additional fertilizers," Premachandran said.

You can read more about the museum here.