Monday 13 May 2013

Strengthening legumes to tackle fertilizer pollution

e! Science News reports on research which shows that by boosting the nitrogen-fixing capacity of leguminous crops such as peas and beans, the environmental impacts of using artificial nitrogen fertilisers can be reduced.
Legumes use iron in the soil to carry out a complex chemical process called nitrogen fixation, which collects atmospheric nitrogen and converts it into organic forms that help the plant grow. When the plant dies, the excess nitrogen is released back into to the soil to help the next crop.
But often legumes are grown in areas with iron-depleted soil, which limits their nitrogen fixation. That's where research can lend a hand. The research team has created the world's first model for how iron is transported in the plant's root nodule to trigger nitrogen fixation. This is the first step in modifying the plants to maximize iron use.

"The long-term goal is to help sustainable agriculture practices and further diminish the environmental damage from overuse of nitrogen fertilizers," said Manuel Gonzalez-Guerrero, lead author of the paper from the Technical University of Madrid (UPM). "This can be done by maximizing the delivery of essential metal oligonutrients to nitrogen-fixing rhizobia."

Read more here.

Friday 10 May 2013

Deep, permeable soils buffer impacts of crop fertilizer on Amazon streams, MBL study finds

Science Codex reports on research carried out in the Southern Amazon showing that some of the damaging impacts of agriculture on fresh water may be buffered by the very deep and highly permeable soils that characterize large areas of the expanding cropland.

The researchers looked specifically at the impacts of soybean agriculture on water quality and quantity at Tanguro Ranch, a 200,000-acre farm similar in climate and geography to large tracts of the Amazon where soybean production, largely for export as animal feed, is expanding rapidly. The ranch has watersheds that are entirely forested, as well as watersheds that are now entirely soybean cropland, allowing for a comparison.
"We were surprised to find that, despite intensive agriculture at Tanguro Ranch, the streams do not appear to be receiving a significant amount of either nitrogen or phosphorus, despite a high application of phosphorus fertilizer to adjacent cropland," says lead researcher Christopher Neill, director of the Ecosystems Center at the Marine Biological Laboratory (MBL).
This is in contrast to many Northern Hemisphere cropland areas where fertilizers are known to add nutrients to the soil that, with rainfall, run off into freshwater streams and rivers, leading to over-fertilization and low-oxygen conditions that endanger fish and other aquatic life.
At Tanguro Ranch, however, "the soils are old and highly weathered, very deep, and likely to be fairly uniform over great depths," Neill says. "Water infiltrates the soil very rapidly, and the soil has a great capacity to absorb the nutrients. It appears to act as an enormous buffer."

Read more here.

Wednesday 8 May 2013

Beneficial exception to no-till rule

A strategic, one-off cultivation may be a viable option for no-till farmers battling to control herbicide-resistant weeds yet retain the long-term benefits no-till farming has brought them.

So says Queensland Country Life, reporting on a three–year research project in the state which has been set up to gauge the impact of a single tillage operation on no-till systems and determine the best timing of such an operation.

Queensland Department of Science, Information Technology, Innovation and Art senior soil scientist Dr Yash Dang, Toowoomba, said the growing incidence of herbicide-resistant, hard-to-kill weeds was one of the biggest threats to no-till farming systems.

“Many weeds have developed resistance to many herbicides,” he said. “With the narrow range of herbicide groups we have, they have developed herbicide resistance and farmers are finding it very difficult to manage.

Trials held in the first stage of the project last year showed that a one-time tillage with chisel or offset disc in long-term no-till helped control winter weeds and slightly improved grain yields and profitability while retaining many of the soil quality benefits of no-till.

Read more here.


Monday 6 May 2013

Unearthing the Value of Soil

The UK version of the Huffington Post carries a fascinating feature on the importance of healthy soils to help us cope with climate, food and biodiversity challenges.

Soil is the most diverse ecosystem on the planet. Just one teaspoon contains as many as one billion bacteria, which provide vital services to support the growth of plant species and the myriad creatures who feed on them. Without healthy soil, everything from human health and food security to the resilience and biodiversity of the planet is at risk. The earth beneath our feet is so important that geomorphologist David R. Montgomery, author of Dirt: The Erosion of Civilizations, regards its quality and abundance as a measure of whether societies flourish or flounder. In the past, those with poor quality earth typically faced the prospect of dwindling in power or moving on to better lands.

"In today's world we're running out of places to move on to", says Montgomery. "The only option is to develop resilient soils."

The article describes the conventional approach to maximising returns from soils depleted by modern food production has been to turn to outside inputs, like greater amounts of fertiliser and irrigation, to induce crops to grow against the odds. These strategies may increase production and profits in the short term, but, says soil scientist Rattan Lal of Ohio State University, any effective solution requires a long-term perspective.

Lal maintains that it's not only possible to restore our "abused and taken-for-granted" soils - but that efforts to conserve and revive the earth benefit far more than just our own food chain. Healthy soils also deliver a range of essential ecosystem services, high among them being the absorption of atmospheric carbon dioxide. When it comes to strategies for solving the complex equation of climate change mitigation, biodiversity preservation, and safeguarding human security, soil conservation and restoration are "low-hanging fruit", says Lal.

Read the feature article here.

Thursday 2 May 2013

Winter crops protect, improve soil reports on how a growing number of farmers in Illinois are growing cover crops to improve their soils.

The reports says that the concept seems one of the hottest topics in the agriculture industry, said Russ Higgins, commercial agriculture educator with University of Illinois Extension and a representative of the Midwest Cover Crops Council.

Cover crops, such as radishes and ryegrass, are a secondary crop planted in the fall to protect and improve soil conditions during the period of time when crops normally wouldn’t grow, he said. Illinois farm fields, unless planted to harvestable crops like winter wheat or multiple seasons of alfalfa hay, generally rest unused in a six- to seven-month window of cool or cold weather.

Cover crops have the ability to take up essential nutrients, including nitrogen, phosphorous and potassium. As the cover crop decomposes, the nutrients become available to benefit the next crop, Higgins said. Cover crops limit soil erosion and improve water quality as they provide a matt of residue to filter surface water. The cover crop can break weed and disease cycles. And some, including root crops like radishes and deep-rooted grasses, can alleviate soil compaction. All of this can lead to greater corn and soybean yields in certain fields.

Read the full article here.

Monday 29 April 2013

Nitrogen key to uptake of other corn nutrients, study shows

No-Till Farmer reports on research that higher maize (corn) yields in the USA are partly due to modern hybrid varieties taking up more nitrogen after flowering than their older counterparts.

Researchers found that modern hybrids (post-1990) took up 27 percent more total nitrogen from the soil after flowering than pre-1990 corn plants. In fact, nitrogen uptake after flowering in post-1990 hybrids averaged 56 percent of the total grain nitrogen at the end of the season.

Primarily, more grain nitrogen came from new nitrogen uptake from soil during grain filling, as opposed to nitrogen being remobilized from plant leaves and stems. The higher amount and duration of nitrogen uptake contributed to superior grain yields even as actual grain nitrogen concentrations declined.

Optimum nitrogen levels increased plants' abilities to absorb phosphorus, potassium and sulphur. Part of the corn plant's response to receiving adequate nitrogen is that progressively higher percentages of total plant phosphorus, potassium and sulfur end up in the grain fraction at harvest.

Read the full report here.

Friday 26 April 2013

Land degradation causes up to five percent loss in farm output

The Business Recorder reports on a study presented at a recent UN conference which has found that loss of land through desertification and drought costs up to five percent of world agricultural gross domestic product (AGDP), or some $450 billion (340 billion euros), annually.
Each year an area roughly three times the size of Switzerland is lost through soil degradation, it said, as 870 million people suffer from chronic hunger. Between four and 12 percent of Africa's AGDP is lost due to degraded land annually, and in Guatemala the figure is 24 percent, the report said.

The Business Recorder report can be found here and more informaiton about the UN conference is available here.

Thursday 25 April 2013

Farming? There’s an app for that

The Drovers' Cattle Network reports on the growing use of smartphones and apps (applications) in farming.

Smartphone apps aren’t just for social networking or entertainment. A growing number of apps make use of smartphone technology to help farmers do their job. Farmers can use apps on smartphones or tablet computers for everything from staying up to date on agriculture news to calculating sprayer tank mix ratios, said Kent Shannon, University of Missouri Extension natural resource engineering specialist.
“In the area of precision agriculture are apps that we can collect geo-reference GPS data from,” Shannon said. “That allows us to do a better job of recording things in the field.” One example is Connected Farm, which lets producers collect scouting information in the field and take pictures that are geo-referenced. There are also several apps that have commodity market information.

Read the full article here.

Tuesday 23 April 2013

Research to examine water savings in agriculture during drought

Waterworld carries a press release from Colorado State University (CSU) describing how a team of CSU agricultural and environmental scientists hopes to pinpoint best management practices in crop production to help conserve water in times of drought, and their project will provide farmers with an online tool to calculate water savings gained from different strategies.
The research project is supported with a grant of $883,000 from the U.S. Department of Agriculture Adaptation to Drought Conservation Innovation Grant. U.S. Sen. Michael Bennet, D-Colo., announced the funding last week.
"We are taking a systematic approach to understand how to effectively manage water in the face of scarcity," said Neil Hansen, associate professor in the CSU Department of Soil and Crop Sciences and project leader. "We want to maximize crop per drop, meaning crop yield per gallon of water. Water is short, and we've got to get as much as we can from the little we've got."
The project will examine water-saving benefits gained with adjustments in:
  • Crop management, including use of cover cropping and drought-tolerant crop varieties;
  • Soil management, including conservation tillage and soil amendments; and
  • Irrigation management, including scheduling and variable rate irrigation, which uses space-based technologies to tailor water application to varying needs within a field.
  • The project also will employ sensors to track soil moisture and crop stress.

Read the full press release on the Waterworld website here.

Friday 19 April 2013

'Skywalker': Aeronautical technology to improve maize yields reports on a project to design a low-cost unmanned aerial vehicle which helps to select the maize varieties which are best adapted to adverse environmental conditions

Drought and poor soil fertility are the leading production constraints in most maize farming systems and reductions in maize yield caused by climate-related stress may be increased under climate change. Skywalker is a remote-controlled plane fitted with a variety of specialised cameras allowing evaluation of the crops' growth, temperature and available soil water of large numbers of maize varieties in only a few minutes. This data will be used to improve the efficiency of maize breeding and speed up the development of drought and low nitrogen tolerant maize varieties for some of the poorest farmers in the world.

Read the full article here.

Wednesday 17 April 2013

New technique simplifies soil organic carbon measurement

EnvironmentalResearchWeb reports that researchers in Kenya have developed a simple technique for mapping soil organic carbon that uses satellite imaging and gives a resolution of 30 m.

Conventional techniques for analysing soil organic carbon can be tedious, time consuming and sensitive to disturbances. Researchers from the World Agroforestry Centre and the International Centre for Tropical Agriculture, have developed a test that overcomes these issues.
The pair used soil data to train models to map soil organic carbon stocks. They found that soil erosion affects soil organic carbon stocks strongly in all sites and across different land-cover types. They also found that inherent soil properties such as sand content are often more important than climate effects alone in determining soil organic carbon dynamics.
The researchers hope to make their maps and models available to other researchers early next year, through a web-based platform that will enable researchers to choose an area of interest and run predictions for soil organic carbon stocks.

Read the full article here.

Monday 15 April 2013

To cut emissions, match fertilizer to soil

An article on Futurity (research news from universities in the US, UK, Canada, and Australia) describes a study published in the Proceedings of the National Academy of Sciences, aimed at understanding the sources of nitrous oxide and nitric oxide by different microbial processes, especially following the application of certain fertilizer nitrogen types.

“Agriculture is the main source of nitrous oxide globally, so this study is a starting point to help us understand how to manage and control it,” says University of California, Davis, professor of soil biogeochemistry William Horwath, whose lab conducted the study.

In the paper, the authors say their results imply that management practices such as fertilizer choice affect how much nitrous oxide is released. Specifically, to reduce nitrous oxide emissions, fertilizer applications of urea should be avoided in soils where oxygen is limited, they write.

On the other hand, practices that increase soil aeration, reduce compaction, and enhance soil structure using organic matter could decrease nitrous oxide emissions from agricultural soils. Using nitrification inhibitors could help, as well.
“The results of this study will change the way we think about the source of nitrous oxide from soil,” Horwath says. “It will help researchers and people making fertilizer recommendations begin to understand that they need to consider different soil processes more explicitly.”

Read the article here.

Friday 12 April 2013

Soils in newly forested areas store substantial carbon that could help offset climate change

e! Science News reports on a paper on soil carbon published by researchers at the University of Michigan.

If you're a land manager trying to assess the potential of forests to offset carbon emissions and climate change by soaking up atmospheric carbon and storing it, what's going on beneath the surface is critical. But while scientists can precisely measure and predict the amount of above-ground carbon accumulating in a forest, the details of soil-carbon accounting have been a bit fuzzy.
Two University of Michigan researchers and their colleagues helped to plug that knowledge gap by analyzing changes in soil carbon that occurred when trees became established on different types of nonforested soils across the United States. U-M ecologist Luke Nave and his colleagues found that, in general, growing trees on formerly nonforested land increases soil carbon. Previous studies have been equivocal about the effects of so-called afforestation on soil carbon levels.
"Collectively, these results demonstrate that planting trees or allowing them to establish naturally on nonforested lands has a significant, positive effect on the amount of carbon held in soils," said Nave, an assistant research scientist at the U-M Biological Station and in the Department of Ecology and Evolutionary Biology.

Read more here.

Thursday 11 April 2013

Surviving The Weed Crisis: Life Beyond Glyphosate

No-Till Farmer carries an article discussing the problems, and solutions, associated with glyphosate-resistant weeds in crops established by no-till. For no-tillers to continue farming in a sustainable manner, they must diversify their weed-control programs and reduce their reliance on post-emergence applications of glyphosate, Southern Illinois University weed specialist Bryan Young says.

Since the mid-1990s, at least 21 varieties of glyphosate-resistant weeds have been identified in the U.S. Problems began to appear [from 2000], especially in no-till acres with glyphosate-resistant marestail (horseweed), Young says. Between 2005 and 2010, the resistance problem mushroomed, with some Midwestern states reporting millions of acres of glyphosate-resistant weeds, mostly marestail and waterhemp.

No-tillers who currently aren’t experiencing glyphosate resistance should not be lulled into a false sense of security. Though some farmers may answer that they’re using full rates of glyphosate to get a consistent killing of weeds, an overreliance on it — even at full rates — can still bring resistance, Young says. And spraying the weeds when they’re small won’t guarantee against resistance, either.

The acronym D.I.R.T. describes the outlook needed for no-tillers to achieve better weed control, says Young.
Diversify: Growers are advised to Diversify their weed-management tactics,
Integrate: Integrate at least two effective modes of control, rather than just relying on a single control measure such as glyphosate, to fix a problem,
Rates: Utilise full rates to improve the consistency of control for residual and foliar herbicides, and
Timing: Apply residual herbicides close to the peak emergence period for problematic weeds.

Read the full article here.

Wednesday 10 April 2013

‘Smart Agriculture’ to overcome vagaries of weather

The Hindu reports on technological developmentsa aimed at helping small and marginal farmers across the Indian state of Kerala to tackle the vagaries of climate-dependent agriculture. Researchers at the Kerala Agricultural University (KAU) and the International Centre for Free and Open Source Software (ICFOSS) have joined hands to develop a technology-assisted system to generate detailed information on soil and agro-climatic conditions. Named Smart Agriculture, the project seeks to utilise precision farming methods to improve crop output.

The researchers are working on an IT-enabled system to provide real time data on soil and micro weather conditions. The Cloud-based platform will be based on sensors installed in each plot to keep a constant tab on different variables. ICFOSS has developed the prototype of a solar-powered remote station for monitoring soil and atmospheric conditions. Working on Open Source hardware and software, it automatically uploads data to the Cloud.

“Precision farming requires specific information on the state of the atmosphere and soil, in terms of parameters such as temperature, humidity, soil pH, rainfall, soil salinity, and wind vector (speed & direction). The data can be used to provide advisories for farmers depending on the type and age of crops they have planted,” says Satish Babu, Director, ICFOSS.

Read the rest of the article here.

Monday 8 April 2013

The role of gypsum in agriculture: 5 key benefits you should know

CropLife reports from the Midwest Soil Improvement Symposium where the latest research and practical insights into using gypsum was presented.

While farmers have used gypsum (calcium sulphate dihydrate) for centuries, it has received renewed attention in recent years. This resurgence is due in large part to ongoing research and practical insights from leading experts that highlight the many benefits of gypsum.

Here are five key (and overlapping) benefits of gypsum highlighted at the symposium:

1. Source of calcium and sulphur for plant nutrition.
2. Corrects soil acidity and treats aluminium toxicity.
3. Improves soil structure.
4. Improves water infiltration.
5. Helps reduce runoff and erosion.

Read the full report here.

Friday 5 April 2013

Just say no to spring tillage, NRCS advises

The Sun Advocate, published in Utah's Carbon County, carries a report urging farmers to avoid spring tillage for the sake of their soils.

Tillage, which was once considered necessary in order to prepare a proper seed bed for planting, comes at a high price in terms of increasing diesel prices and labour costs. But according to Niels Hansen, a soil health specialist with USDA's Natural Resources Conservation Service (NRCS) in Salt Lake City, the bigger, long-term cost may come at the expense of the health and function of the soil itself - resulting in lower yields, higher input costs and reduced drought resilience for Utah farms.

"Tillage is incredibly destructive to the soil structure and to the soil ecosystem," Hansen said. "In healthy soil you have 50 percent air and water - which is made possible by the pore space in the soil - and 50 percent mineral and organic matter. But tillage collapses and destroys that structure, making the soil vulnerable to erosion and compaction," he said.

Fortunately, more and more irrigated and dryland producers in Utah are farming with systems to build soil health, Hansen said. "Using a suite of conservation practices, like no-till farming and diverse cover crops," he said, "they're keeping living plants in the soil as long as possible and they're keeping the soil surface covered with residue year round."

Read the full article here.

Thursday 4 April 2013

Survey highlights increased use of precision farming techniques

The UK's Department for Environment, Food and Rural Affairs (DEFRA) has just published the findings of its annual Farm Practices Survey. The survey looks at how farm practices are affected by environmental issues and assesses the impact of agriculture on the environment. Topics vary from year to year so the content of the survey changes annually, ensuring that the information collected is relevant and current.

The autumn 2012 survey, the results of which have just been published, included questions on the use of precision agriculture, which can help to improve the efficiency of farm operations, including cultivation and better targeted fertiliser and agrochemical applications.

Of all the precision farming techniques asked about, the use of GPS remains the most popular and has increased the most between 2009 and 2012; 14% were using the technique in 2009, rising to 22% in 2012. Soil mapping and yield mapping have also seen increases.

When asked for their reasons for using precision farming techniques, 85% of respondents said it was to improve accuracy, 78% said to reduce input costs and 55% wanted to improve soil conditions. Of those farms which don't use any kind of precision technology, 47% said that it wasn't cost effective to do so or that the initial setup costs were too high, 28% said that it wasn't suitable for their farm type or size and 27% said that it was too complicated to use.

Read more about the survey here.