Sub-soil testing could lead to nitrogen savings

The Australian Stock Journal reports on research revealing that many growers could make savings on nitrogen fertiliser by conducting subsoil testing to obtain a more accurate picture of nutrients available to their crops.

Apparently, few growers currently conduct nutrient testing in the subsoil, instead focussing on the topsoil.

The Grains Research and Development Corporation (GRDC) supported research is being conducted in WA by Murdoch University, CSIRO and the Department of Agriculture and Food (DAFWA). It has shown that, in many circumstances, nitrate stored in the sub-soil is available to crop roots.

Project leader Richard Bell, Professor in Sustainable Land Management at Murdoch University, said this meant many growers could potentially reduce nitrogen fertiliser rates and applications.
 

“Situations where subsoil nitrates are available to crops include heavier textured soils and drier seasons when nitrates are unlikely to leach away before roots can reach them,” he said. “However, access to subsoil nitrates by crop roots can be reduced by soil constraints such as hardpans or aluminium toxicity.”

Read more here.

Toxic-tolerant maize moves closer to reality

PlanetSave reports on new research from the U.S. Department of Agriculture and Cornell University which shows that corn (maize) crops capable of being grown in toxic soils are moving closer to reality. The new research has been attempting to unravel the reasons for why some maize plants can tolerate toxic aluminum in soil, and some can’t.

 

“Aluminum toxicity comes close to rivaling drought as a food-security threat in critical tropical food-producing regions. Acidic soils dissolve aluminum from clays in the soil, making it toxic to plant roots in half the world’s arable land,” said senior author Leon Kochian, director of the USDA Agriculture Research Service Plant, Soil and Nutrition Laboratory at Cornell.

 

“The MATE1 gene, which was found in triplicate in aluminum-tolerant maize, turns on in the presence of aluminum ions and expresses a protein that transports citric acid from root tips into the soil, which binds to and locks up aluminum, thereby preventing it from harming roots.”

 

Read more here.

Removing corn stover? Keep your soil intact

Agriculture.com reports on a study which illustrates the soil benefits associated with leaving unwanted plant material and crop residues, in this case maize stover, on the soil after harvest.

The article reports that a growing amount of corn stover (leaves and stalks) is removed from fields during or after harvest. But the removal of that critical crop residue could be causing harm to your fields' future viability, the results of a new study show.

The potential danger is 2-fold; first, there's the potential increase in greenhouse gas emissions caused by the release of nutrients and accompanying carbon while the stalks are being removed from the field. Then, there's the loss of soil structures caused by another tillage pass in the field.

"For a given crop rotation and tillage system, as we simulated an increase in the rate of stover removal we found an increase in loss of sediment from crop fields, an increase in greenhouse gas flux to the atmosphere and a reduction in nitrate and total phosphorus delivered to waterways," says Purdue University ag economist Ben Gramig. "While optimizing production to maximize stover harvest at the lowest possible cost may lead to a reduction in nutrients delivered to rivers and streams, this comes at the expense of increased soil erosion and greenhouse gas emissions."

As much as 3.5 tons of greenhouse gas and 1.1 ton of soil sediment per acre is lost from a field under conventional tillage when just over half the stover is removed, a process that nets around 2.7 tons of of the cellulosic ethanol feedstock, according to Gramig's research.

Read more here.

Michelin offers soil-protection advice

Michelin has created a free downloadable guide advising farmers and contractors on how they can better protect their soil. The easy-to-follow booklet entitled, ‘Protect Your Soil’ offers a range of useful hints and tips from determining the different types of soil to ways to prevent soil damage by compaction.

Split into five sections, including chapters on the impact of tyres and the benefits of fitting tyres with MICHELIN’s Ultraflex technologies, the booklet offers a number of practical solutions for overcoming soil compaction.

“Trying to reduce soil compaction is at the forefront of many farmers’ and contractors’ minds and as such we wanted to produce an easy-to-use and interesting guide, that would help those in the agricultural industry better understand their soil, and the steps they need to take in order to reduce compaction”, says Mike Lawton, Commercial Director of Michelin’s Agriculture division.

Read more and download the booklet here.

Cuba Continues Work on Soil Improvement

The Prensa Latina news agency reported on the March 13 that increased production of organic fertilizers and bio-fertilizers, along with conservation activities are among the measures adopted in 2012 by Cuba to improve its soils. According to Dagoberto Rodriguez, director of the Institute of Soil at the Ministry of Agriculture, the production of organic fertilizers and bio-fertilizers grew last year by 4.5 percent over 2011.

In relation to the conservation and improvement of soils to produce higher agricultural yields, the official told Granma newspaper that about 64,500 hectares benefited from the measures. Rodriguez also said that studies are underway aimed at improving the care of soil, which contemplate a change in nitrogen fertilization.

In this regard, the director of the Institute of Soils considered the link between research projects and production to be a priority for the Ministry of Agriculture, along with the intensification of work aimed at developing bio-fertilizers programs that allow for the recovery of organic matter in soils, affected by overexposure to chemicals.

Read more here.

India farmers think big but grow micro to enrich their soil

The Guardian reports that since 2009, the south-west Indian state of Karnataka, the country's eighth largest which has a population of 61 million people, has pursued an agricultural programme called Bhoo Chetana, or soil rejuvenation, that has seen productivity shoot up by 20-50%, according to state officials. The gross value of crop production increased by $130m (£87.5m) in 2011. Its achievements have been recognised by the central government and attracted the interest of the neighbouring state of Andhra Pradesh and, further afield, the Philippines.

The rationale is that farmers can increase productivity and income through the judicious use of micronutrients, such as zinc, boron and sulphur, while simultaneously reducing the use of fertilisers, such as nitrogen and potash, that contaminate ground water – one of the unintended consequences of the green revolution in the 1960s and 1970s.

The system is based on soil sampling: farmers collect the samples, encouraging grassroots participation from the start. Once the samples are examined, fertiliser and micronutrients recommendations are given for different areas in different districts.

Read more here.

Snow is mostly a mirage for soil moisture

After last year's major drought in the US, farmers are thirstily eyeing the layer of snow covering the fields of the Great Plains and Midwest. "This snow is a huge blessing, and our subsoil has a lot more room to store moisture," said a Kansas farmer on Agriculture.com after last week's big snow in the state. Heavy snow fell earlier in March in some of the neediest areas. Coverage included northwest Texas, west central Oklahoma and far south central Kansas, said Don Keeney, MDA EarthSat Weather.

"The snow is now melting across the southern Plains, which will help to improve soil moisture for wheat," Keeney noted in a e-mail newsletter at the beginning of March.

But, that large blanket of white across the country is mostly a mirage in terms of recharging soil moisture. By the time the soil thaws, most of the moisture will be gone, thanks to runoff and sublimation, says Matt Helmers, an Iowa State University agricultural and biosystems engineer.

"Things are still frozen underneath in many areas, so that once it warms up we will probably lose the majority of the water to runoff, rather than infiltration," Helmers told Agriculture.com.

Read more here.