Mussel shells used to fertilize soil

Fish Information and Services reports on a study by University of Madrid researchers which has found that treating acid soils with mussel shells can increase their pH and reduce levels of aluminium in the soil.

The reports explains that the findings offer great potential in demonstrating novel ways of getting rid of industrial waste by reusing it to improve soil quality. Currently, mussel shells are discarded so there are cost and aesthetic issues. According to the experts, most soils in the Spanish study area are acid and in many of them slurry is used in order to return nutrients to the soil. Much of the work was done in the Spanish region of Galicia, which has a large fishing industry generating substantial quantities of waste.

Mussel shell contains calcium carbonate (from 95 per cent to 99 per cent of the shell weight) and small amounts of nitrogen, sulfur, phosphorus, potassium and magnesium, all of which are beneficial to the soil and plant life.

No-till cropping can improve air quality, say scientists

California's Central Valley Business Times reports that experiments in the dry, wheat-growing palouse region of eastern Washington State might lead to cleaner air in the Central Valley of California.

Studies by U.S. Department of Agriculture (USDA) scientists show some no-till management systems can lower atmospheric levels of PM10 — soil particles and other material 10 microns or less in diameter that degrade air quality — that are eroded from crop fields by the wind. The findings could help reduce erosion and assist communities in complying with federal air quality regulations, the USDA says.

Agricultural Research Service (ARS) research leader Brenton Sharratt and ARS agronomist Frank Young conducted the research. “In the inland Pacific Northwest, when atmospheric levels of PM10 exceed federal limits, it’s usually because of erosion from farm lands,” says Mr. Sharratt. “Since the U.S. Environmental Protection Agency regulates air quality, farmers in this area are looking for ways to reduce erosion from their fields and assist communities in complying with regulations."

Farmers in the inland Pacific Northwest favour winter wheat-summer fallow production systems so that crops can germinate and grow during late summer and fall. But controlling weeds and conserving soil water during the summer can require up to eight tillage passes. This produces a dry, loose layer of fine soil particles that can be easily eroded by strong summer winds. “One major windstorm can generate enough airborne dust to exceed air quality standards for PM10,” says Mr. Sharratt. “But annual no-till cereal crops appear to be a viable strategy that farmers can use to control erosion and meet air quality regulations in the Pacific Northwest.” The next challenge is finding ways to make annual no-till crop systems as profitable as the current winter wheat/fallow system.

Read the rest of the article here.

Science supports ‘anecdotal’ biological farming experience

New Zealand's online Business Scoop reports that farmers across the country are increasingly finding positive solutions to many on-farm challenges; proving that farming can provide both economic and ecological outcomes. For many years these farmers have been vocally dismissed by a faction that believes it is not possible to be profitable and to take care of New Zealand’s ‘clean green image’. The Association of Biological Farmers (ABF) has just completed a one year project showcasing some of the successful farmers and growers around the country who are bucking a trend of diminishing natural capital returns.

ABF has collated data from research from New Zealand and around the world supporting the ‘anecdotal’ on-farm experiences of these innovative and progressive farmers. This research shows that biological farming systems use significantly less agro-chemicals, are more energy efficient, reduce greenhouse gas emissions, improve soil qualities without reducing output and financial benefits; all in all resulting in a more ecologically, economically and socially more robust model compared to the conventional farming approach.

Read the full Scoop report here and the ABF's project report summary here.

South Australia's soil health initiative

Another report from Stock and Land, this time on the benchmarking of the health and quality of South Australian cropping soils through an innovative online resource. The website, soilquality.org.au, enables growers to compare the condition of their soils with that of their regional farming counterparts.

The new resource provides growers with insightful paddock data, assisting them in their efforts to improve yields and productivity. Dr Murray Unkovich, from the University of Adelaide’s School of Agriculture Food and Wine, said development of the online tool had been strongly supported by the GRDC which recognised the importance of comparative data in informing growers about the status of their soils. “For growers to know how their property’s soils fit within the local region is very useful in terms of gaining a better understanding of the health of their soils,” Dr Unkovich said.

Read more on the initiative here and visit the soil quality website here.

Suppressive soils offer defence against grain diseases

Australia's Stock and Land journal argues that soil biology is tipped to be the ‘next big thing’ in terms of productivity gains and reports on a five-year research programme is currently being funded by the Grains Research and Development Corporation (GRDC) to address some of the knowledge gaps.   The journal suggests that high rainfall zone (HRZ) grain growers stand to increase yields and save significant amounts of money on chemicals, if the secrets of suppressive soils can be unlocked.

Associate Professor Pauline Mele, LaTrobe University and principal research scientist, Department of Primary Industries Victoria (DPI), is co-ordinating an investment in soil biology that includes a team of some 90 researchers working on 15 different projects as part of the GRDC Soil Biology Initiative II.

She says understanding suppressive soils is one of the priorities, along with monitoring soil quality for better decision making and improving nutrient availability.   “There are soils right across the country where the incidence or severity of disease is suppressed, even in the presence of the pathogen that causes it, a host plant and a favourable environment,”

Professor Mele said.   “In fact, we believe every soil has the potential to be suppressive – it’s just a matter of working out what management techniques will encourage it.

“We know the effect is due to the presence of a diverse range of ‘good’ micro-organisms, because upsetting the balance or sterilising the soil can cause the disease to strike with a vengeance.   At this stage, though, we’re still trying to identify exactly what organisms, or combination of organisms, are doing the work.”

Read more here.

Bacteria turn CO2 into soil improver

TG Daily reports how tiny microbes and a tropical tree can be used to lock up carbon dioxide - and turn it into an agricultural soil improver. University of Edinburgh scientists have discovered that when the Iroko tree is grown in dry, acidic soil and treated with a combination of natural fungus and bacteria, it produces a mineral in the soil around its roots.

It does this by combining calcium from the earth with CO2 from the atmosphere.   The bacteria then create the conditions under which the resulting mineral turns into limestone.

The process, which has already been used successfully in West Africa and is being tested in Bolivia, Haiti and India, locks carbon into the soil, keeping it out of the atmosphere, with the limestone deposited in the soil also benefiting agricultural production. "By taking advantage of this natural limestone-producing process, we have a low-tech, safe, readily-employed and easily maintained way to lock carbon out of the atmosphere, while enriching farming conditions in tropical countries," says Dr Bryne Ngwenya of the University of Edinburgh's School of GeoSciences.

Read more here.

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.

Global warming threat seen in fertile soil of northeastern US forests

Brightsurf.com 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 Brightsurf.com here.

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.

Soil carbon and soil water: perspectives from Down Under

A couple of useful technical pieces from the Australian Grains Research and Development Corporation.

What is soil organic carbon? “Although determining the total amount of organic carbon in soil is important, it does not tell us anything about the type of organic carbon present. For example, is the organic carbon dominated by pieces of plant residue or more recalcitrant charcoal?

“Understanding the partitioning of soil carbon within these different forms will help define the vulnerability of the carbon to subsequent change and the contribution that soil carbon may make to soil productivity. Therefore determining both the amount and the composition of soil organic carbon will be required to understand the implications of management practices on soil carbon stocks and vulnerability to change and on soil productivity.” 

And an interesting piece on soil water use monitoring and crop management. “Practices available to farmers to improve transpiration and transpiration efficiency include selection of drought-tolerant species, manipulation of crop morphology, reduction of weeds, pests and diseases and the use of cultural practices such as sequences of different crops, time of sowing, intercropping, use of fertilisers, fallowing, reduced tillage, stubble retention and water harvesting.

“Tools available for farmers to monitor water supply and use include direct soil sampling techniques and indirect water monitoring sensors. Direct sampling is typically prohibitively expensive but various low-cost sensors suffer from a technology divide. Simulation modelling is now a well established technology to assist in crop management decision making, but this too suffers from a technology divide.”

Secret soil cracks linger, despite surface sealing

Here's an interesting story which is highly relevant to parts of the UK at the moment, where a prolonged drought has been followed by intense, heavy rainfall in the past few weeks.   Are those heavy soils really suddenly waterlogged, or is it just surface water sitting on top of a compacted soil layer which is hiding drought-induced cracks further down?

BrightSurf.com reports that deep cracks in soil can remain open underground even after they have visibly sealed on the surface, a new study has found. The results could have important implications for agricultural management around the timing and intensity of water and pesticide applications.

Cracks in the soil, which open up when the soil is particularly dry, provide "preferential pathways" allowing water to flow much faster than it would through non-cracked soil, rapidly transporting nutrients and pesticides beyond the crops' root-zone. If the plants can't access the water it has effectively been wasted.

Studying this preferential flow, the researchers have found that surface appearances can be deceiving. "We showed that soil cracks that developed in dry periods remain open as preferential flow paths, even after the cracks are visually closed," said lead author Dr Anna-Katrin Greve, a postdoctoral fellow with UNSW's Connected Waters Initiative. She found, however, that lower water application / irrigation intensity will give soil cracks time to close and more frequent irrigations could prevent the soil cracks from reforming.

Read more here.

Improved roots will boost crops

An article in Science Alert reports that University of Western Australia researchers say that the "next frontier" of agricultural science is understanding the root system and function of crop plants to significantly increase grain production, keep farms viable and help continue to feed the world despite the onset of increasing drought and climate change. Scientists at the university have experimented with lupin roots to try to improve the water use and nutrient uptake of narrow-leaf lupin varieties that account for half of all grain legumes produced in Australia - an industry worth more than $600 million a year.

The study, published in the international journal Plant and Soil, warned that Australian grain producers faced increasing threats from poor local soils, harsh growing conditions and declining, less-predictable rainfall due to climate change. To help address this, a team led by UWA-based Chief Investigators Winthrop Professor Zed Rengel and Winthrop Professor Kadambot Siddique used new screening techniques and advanced computer modelling to understand lupin root systems variability.

Fertilizer Tree Systems enrich soils naturally

The Worldwatch 'Nourishing the Planet' blog reports on a simple but ingenious means of tackling poor and degrading soil quality in Africa.  The article quotes a report, “Agricultural success from Africa: the case of fertilizer tree systems in southern Africa (Malawi, Tanzania, Mozambique, Zambia and Zimbabwe),” from the International Journal of Agricultural Sustainability, which states that simple “Fertilizer Tree Systems” (FTS) can double maize production in soil that is low in nitrogen.   A type of agroforestry, FTS incorporate nitrogen-fixing trees and shrubs into agricultural fields, usually inter-planted with food crops.  These trees take in atmospheric nitrogen and return it to the soil, where it serves as a nutrient for plants.

The article goes on to say that soil analyses by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and others in the 1980s revealed nitrogen to be a limiting factor in many African soils.   In response, on-farm studies in the 1990s showed that FTS with the right species could increase crop yields with or without mineral fertilizers.   FTS are much cheaper for farmers to implement than buying fertilizer inputs, and represent a more holistic approach to soil management.   FTS scaling-up programs were broadly implemented about ten years ago, and in that time the number of small-holder farmers using these techniques has ballooned from a few hundred to more than 250,000 in Malawi, Tanzania, Mozambique, Zambia, and Zimbabwe.

Read the full article here.

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.

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.

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.

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."

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.

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.

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.

'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.