Monday, 30 April 2012

Mice – Are they here to stay?

The Australian Grains Research and Development Corpoation (GRDC)has reported on the phenomenon of mouse plagues in South Australia, and how an increase in the frequency of these epidemics is an unexpected side effect of an increase in minimum tillage in cereal production.

According to this GRDC research update, mouse plagues were recorded in South Australia as early as 1890: “the land swarms with mice; they destroy or damage everything that is eatable; a large quantity of the sown grain has been devoured; no crop is expected from over 100 acres; the farmer will not resow now it is so late - Kapunda Herald, June 1890”.

There has, however, been a marked increase in plague frequency in the last 30 years. On average a plague was recorded somewhere in South Australia every 5-6 years between 1900 and 1980, but every 4 years since then, with severe plagues in 1980, 1993, 2010 and 2011. In addition, substantial localised damage occurred in several other years and some growers have had to bait every 2nd year for the last decade.

The increased frequency of plagues has been caused by changes in cropping systems that use less cultivation, stubble retention, more diverse crops, and fewer livestock. These changes provide mice with better cover, more high-quality food, undisturbed burrows and easy access to sown grain. The end result is both more mice for any given seasonal conditions, and more damage to crops for a given number of mice.

Read the full update here.

Friday, 27 April 2012

Fertilizer Use Responsible for Increase in Nitrous Oxide in Atmosphere

Science Daily reports that University of California, Berkeley, chemists have found a smoking gun proving that increased fertilizer use over the past 50 years is responsible for a dramatic rise in atmospheric nitrous oxide, which is a major greenhouse gas contributing to global climate change.

Climate scientists have assumed that the cause of the increased nitrous oxide was nitrogen-based fertilizer, which stimulates microbes in the soil to convert nitrogen to nitrous oxide at a faster rate than normal. The new study, reported in the April issue of the journal Nature Geoscience, uses nitrogen isotope data to identify the unmistakable fingerprint of fertilizer use in archived air samples from Antarctica and Tasmania.

"We are not vilifying fertilizer. We can't just stop using fertilizer," said study leader Kristie Boering, a UC Berkeley professor of chemistry and of earth and planetary science. "But we hope this study will contribute to changes in fertilizer use and agricultural practices that will help to mitigate the release of nitrous oxide into the atmosphere."

Read the full article here.

Thursday, 19 April 2012

Farmers assess centuries-old system for marginal land

A report on Australia's ABC News tells of growing interest among farmers in systems used in Spain and Portugal to produce high quality pork products in a particularly dry environment.

Farmers in drought-stricken Salmon Gums, near Esperance in Western Australia, are considering a centuries-old Mediterranean farming system as a way to improve marginal land. The area has been through four years of drought and farmers are exploring alternative production systems in order to survive. Some farmers are looking at Dehesa, which creates a symbiotic relationship between trees, pasture and animals to boost the land's productivity.

WA's agricultural region has a Mediterranean climate and so should be suited to tis method which is used on the Iberian Peninsula. Climates are characterised by long, hot, dry summers with cool winters, as well as challenging soil types. Dehesa, known as Montados in Portugal, was developed around the middle ages as a means to cultivate the land in the harsh climate.

Dr Imma Farre grew up on a farming property in Spain and now works at the Department of Agriculture and Food as a research officer. She says estates in the south west corner of the Iberian Peninsula grow Holm Oak and Cork Oak trees on their land for a number of reasons.

"The Cork Oak is harvested for cork while the acorns, which drop from the Holm Oak, feed the livestock," she said. Rather than produce large yields, the farmers have developed a premium high value product, known as Iberian pork ham. "When the pigs eat the Holm Acorns that fall from the tree, the meat takes on a unique taste that is highly sort and sells at a premium price," Dr Farre said. The trees also provide shelter and shade for the animals, as well as nutrients and protection against erosion for the soil.

Read more here about how the WA Department of Agriculture and Food is researching and developing ways to protect farming against a changing climate.


Thursday, 5 April 2012

The world needs new ways to grow food

NJ.com carries a great blog entry on something which fascinates me - perennial crops.

Author Peter C. Kahn, a professor of biochemistry at Rutgers University in New Jersey, USA, argues that "unless we rethink the way we grow our food and use our resources, more and more people will go hungry. For half a century, he says, we’ve concentrated on growing annual crops such as wheat, corn and rice — crops that have to be planted and harvested every year, wearing out the land and using vast amounts of water for irrigation. This is not sustainable."

He continues by saying "that we can reverse the trend by reinvesting in agriculture, especially in perennial crops — plants that don’t have to be replanted every year. Perennials can produce food and fuel, and their cultivation is less damaging to land and water. Perennials include food and fuel-producing trees, grasses and — at least potentially — perennial variations of many crops now cultivated annually."

Wednesday, 4 April 2012

6 Reasons Organics Can Feed the World

Ok, so I know this is isn’t simply about soil and water, but please indulge me while I climb up onto my soapbox for a rather long posting.

So it’s time for another of those ‘reasons why organic farming is the best and conventional agriculture will kill us all’ articles, this time from the Huffington Post. I’ll come on to its content in a minute. These articles, and the same tired arguments, appear time after time and only serve to reinforce the unhelpful polarisation between the organic and conventional sectors which has developed and strengthened in the past few decades.

What would be far more helpful in the global debate of climate change, environmental degradation and ‘how are we going to feed the 9 billion by 2050’ would be a recognition by all that there is not one single agricultural system which we should all be following – successful food production will depend on a range of systems, including organic and conventional, all working together.

Monday, 2 April 2012

Deeper soil tests fill in missing knowledge

Experts in Queensland are advocating soil testing for P and K at depths of up to 30cm deep, rather than in just the top 10cm layer which is traditionally tested, according to the Queensland and Country Life.

The article says that testing deeper in the soil profile can provide clues to the fertiliser needs in the top 10 centimetres.

Dr Mike Bell, Queensland Alliance for Agriculture and Food Innovation (QAAFI) and David Lester, Department of Employment, Economic Development and Innovation (DEEDI) advocate testing for phosphorus and potassium in the 10-30cm layer as well as the 0-10cm layer.

"This further test can fill in missing information about the background fertility of the soils we are trying to manage," Dr Bell said. "Growers baulk at conducting another costly soil test, but once an initial assessment has been made, the normal 0-10cm monitoring can be resumed.

"Fertility in deeper layers changes more slowly than in the top 10cm, where crop residues and starter fertiliser can make significant impacts from season to season. However, what is in these deeper layers can define the fertiliser strategy needed to maximise productivity and fertiliser use efficiency, and this has been the focus of the current research programme."

Read the rest of the article here.