Global Cropland

http://earthobservatory.nasa.gov/IOTD/view.php?id=76605&src=eoa-iotd

lobal Croplands

acquired 2000 - 2008download large Global Croplands image (630 KB, PNG, 3252x1632)

With seven billion people now living on Earth, the ever growing demand is putting unprecedented pressure on global resources—especially forests, water, and food. How can Earth’s resources be managed best to support so many people? One key is tracking the sum of what is available, and perhaps nothing is better suited to that task than satellites.

These two images show food production on both a global scale and a landscape scale. Made with data from the Moderate Resolution Imaging Spectroradiometer (MODIS), the top image shows where crops are grown throughout the world. Green areas are cropland, while tan areas are other types of land cover. In the last 40 years, cropland has increased by 70 percent to feed a growing population. Crops now cover about 40 percent of Earth’s land.

The lower image provides a landscape scale view of farming. The Landsat 7 satellite acquired the natural-color image on July 31, 2002. Bright green and gold fields stand out in stark contrast to the arid landscape along the Columbia River in western Washington. At this scale it is possible to gauge how healthy a crop is and estimate how much food it might produce. The United States Department of Agriculture uses such satellite data extensively to help determine where, when, and which crops are planted each year. They also use it to predict yields and to make commodity forecasts.

Measurements from the Landsat satellite also make it possible to tell how much water the crops consume in an arid environment. Such measurements are likely to become more important as demands on limited water resources increase. Currently, agriculture accounts for 85 percent of the world’s fresh water consumption.

“What we’ve done with satellites over the past 40 years is revolutionize how we monitor agriculture, forests, fresh water consumption, and other Earth resources required by the global population,” said James Irons, Landsat project scientist at NASA’s Goddard Space Flight Center. The worldwide pressure of feeding everyone requires a tool that has an impartial, world-wide view, making satellites a unique resource for scientists and policymakers alike.

NASA Earth Observatory image created by Jesse Allen and Robert Simmon, using Landsat data provided by theUnited States Geological Survey. Caption by Holli Riebeek, partly adapted from Using satellites to help the Earth sustain seven billion people.

Silicon in Agriculture - Brazil - Sifol

http://www.diatom.com.br/en-US/products/sifol

Sifol

Plant Silicon

Product contains a high concentration of Silicon micro-nutrient, offering great benefits to agriculture, such as:

• Increase in productivity;
• Formation of physical barrier;
• Prevention or increase of plant resistance to toxic elements and salinity;
• Improve of photosynthesis rate;
• Increase of structural rigidity of tissues;
• Improve of plant's architecture by accumulating silicon in the cuticle, avoiding lodging;
• Regulation of plant's water loss by transpiration.

Silicon in Agriculture - Brazil

http://www.diatom.com.br/en-US/news/item/silicon-and-plant-s-resistance-to-pathogenic-fungus-attacks

Article: Silicon and plant's resistance to pathogenic fungus attacks

Article by agronomist Oscar Fontão Lima Filho (Embrapa) talks about the importance of silicon to combat pathogenic fungi.

3342010-03-03T12:34:00-03:00America/Sao_PauloMarch2010Wed, 03 Mar 2010 12:34:00 -030003pm31
Source: Embrapa

The benefits of adding plant ashes and animal manure to the soil to increase productivity has been known by farmers for thousands of years. This and a number of other products processed by men – in the form of fertilizers and soil acidity corrective – are sources of the plant nutrients, that is, mineral elements considered essential for plants to grow and to complete their life circle, playing several vital roles in plant metabolism.

The lack or excess of one or more of this minerals affects not only growth and productivity, but may also have an impact on plants resistance or tolerance to diseases and plagues. Resistance is basically determined by the ability the host has to limit penetration, development and/or reproduction of the invading agent. Tolerance, on the other hand, is characterized by the plant's ability to keep growing in a satisfactory way, while being infected or attacked by plague. Even being genetically controlled, resistance and tolerance are highly influenced by environmental factors. Among these, we highlight the mineral nutrition of the plant, whose soil fertility can be manipulated by means of fertilization and acidity correction.

Science has already demonstrated the involvement of silicon in several structural, physiologic and biochemical aspects of plants' lives, with very diverse roles. Silicon plays an important role in plant-environment relations, as it can provide culture with better conditions to resist climatic, edaphic and biological adversities, leading to an increase in production volume and quality. Stresses caused by extreme temperatures, short summers and heavy or toxic metals, for instance, can have its effects reduced by the use of silicon. One of the most important beneficial effects is silicon ability to reduce plants susceptibility to diseases caused by fungus.

Plants resistance to diseases can be increased by forming mechanical barriers and/or by changing the plant's chemical responses to the parasite attack, thus increasing the synthesis of toxins that can act inhibiting or repelling substances. Mechanical barriers include changes in anatomy, such as thicker epidermic cells and a higher degree of lignification and/or silicification (silicon impregnation). The amorphous silica located in the cell wall has a marked effect on the cellular wall physical properties. When it is accumulated in the cells of the epidermal layer, silicon can be a stable physical barrier to the penetration of some fungus, specially in grass. In this aspect, the role of silicon incorporated to the cellular wall is similar to that of the lignin – which is a structural component resistant to compression.

Besides the physical barrier, due to the accumulation in the epidermis of leaves, silicon also activates genes involved in the production of secondary compounds of metabolism, such as Polyphenols, and enzymes related to plants' defense mechanisms. This way, the increase of silicon in plant tissues increases plant's resistance to pathogenic fungus attack, due to the supplemental production of toxins that can act as substances inhibiting the pathogenic. Some examples of diseases which find resistance of the host with silicon supplementation include rice blast fungus, diaporthe sojae in soy, Powdery mildew in wheat, soy, barley, cucumber and tomato, Rhizoctoniose in rice and sorghum , cercospora beticola in coffee trees, among others.

The technology based on the use of silicon is clean and sustainable, with a great potential to reduce the use of agrochemical and increase productivity through a more balanced and physiologically more efficient nutrition, which means more productive and vigorous plants, with less diseases.

Oscar Fontão de Lima Filho

Click here to access more articles about the benefits of silicon to agriculture

Silica in Agriculture

http://silife.nl/index.php?option=com_content&view=article&id=55&Itemid=98

Agriculture: results

There is a growing recognition about the importance of silicon for plants.
Nowadays silicates are used as fertilizers.
But much more research is needed.

The use of silicates highlights the importance of silicon for life e.g. plants.

For agriculture, the relevant silicon compounds are:

1. silicates
2. silicic acid

Silicates are used to improve the structure and fertility of the soil.
Silicates can compensate for acid soils, for salt, for access of aluminium and iron.
But moreover, silicates are the source for silicic acid being the silicon key molecule to optimize metabolism, plant growth and optimal yield.
The transformation to silicic acid is a complicated (and limited) process.
And the (ortho-)silicic acid molecule is very unstable, so only (very) limited quantities are found in rivers, water and soil.

Silicic acid is absorbed by organisms like plants and animals.
In plants the effects of (bioavailable) silicic acid are more resistance of roots, stem and leaves, improved metabolism, optimal growth and high yields with e.g. stronger fruits or grains.

Biochar - Phosphorus

http://www.waterandwastewater.com/www_services/news_center/publish/article_002461.shtml

“Biochar” Used to Remove Phosphate from Water
By University of Florida May 12, 2011
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Gainesville, FL — Phosphate poses one of Florida’s ongoing water-quality challenges but a process developed by University of Florida researchers could provide an affordable solution, using partially burned organic matter called biochar to remove the mineral.

The process also yields methane gas usable as fuel and phosphate-laden carbon suitable for enriching soil, according to Bin Gao and Pratap Pullammanappallil, assistant professors in UF’s agricultural and biological engineering department, part of the Institute of Food and Agricultural Sciences. Crop wastes would provide raw material for the biochar.

A laboratory study demonstrating the effectiveness of biochar for phosphate removal appears in the current issue of the journal Bioresource Technology.

The study involved beet tailings, which are culled beets, scraps and weeds removed from shipments of sugar beets destined for processing to make sugar, said Gao, one of the authors. In the U.S., sugar beets are grown primarily in the Northeast and upper Midwest, but the technology can be adapted to other materials, he said.

“It’s really sustainable,” Gao said. “We will see if it can be commercialized.”

UF has filed a patent application for the phosphate-removal process, Gao said. Wastewater treatment facility representatives have shown interest in the technology, he said.
Phosphate is used to make fertilizers, pesticides and detergents. Florida produces about one-fourth of the world’s phosphate.

Florida’s surface waters sometimes contain large amounts of phosphate, arising from natural sources or human activity. Because the chemical can spur algae growth, it has caused water-quality concerns in some communities.

Some water treatment plants filter phosphate from wastewater but existing methods have drawbacks, including high cost, low efficiency and hazardous byproducts.

In the study, researchers started by collecting solid residues left after beet tailings were fermented in a device called an anaerobic digester, which yields methane gas. The material was baked at about 1,100 degrees Fahrenheit to make biochar.

The biochar was added to a water-and-phosphate solution and mixed for 24 hours. It removed about three-fourths of the phosphate, much better results than researchers obtained with other compounds, including commercial water-treatment materials. The phosphate-laden biochar can be applied directly to soils as a slow-release fertilizer.

The research team plans to investigate whether biochar could remove nitrogen from wastewater. Nitrogen can stimulate algae growth in surface water.

The research team has also been testing the potential for biochar to purify water of heavy metals including lead and copper, he said. Part of the challenge involves pinpointing raw materials with the greatest affinity for a particular contaminant. And used biochar packed with toxic metals would have to be regenerated or handled as hazardous waste.

Previous UF studies have demonstrated the potential value of producing methane gas by fermenting crop waste. Pullammanappallil specializes in this area and regularly collaborates with Gao on biochar studies.

Perhaps the biggest challenge researchers face is making biomass technology more cost-effective. Pullammanappallil recently helped design, build and operate an anaerobic digester at an American Crystal Sugar Company facility in Moorhead, Minn.

The digester processed beet tailings like those used in the study, and worked well, said Dave Malmskog, the company’s business development director at Moorhead. But when the research grant funding the project ended, the company found it wasn’t practical to continue.

Nonetheless, the researchers remain optimistic that the process can be made cost-effective.

“Florida agricultural industries could benefit,” Pullammanappallil said. “You could do this with any biomass — sugarcane bagasse, citrus pulp.”

Source: http://www.ufl.edu/