Salinity and Australian Food Crops in a Changed Climate

Over-irrigation and poor drainage of the soil is a main contributor to salinity. Salt stress effects about 20% of the world’s total land-mass. It has been reported that salt stress affects 50% of the global cropland (Tavili & Biniaz, 2009). The Australian soils are subject to high levels of salinity. This is a result of historic land clearing associated with pasture and cropping land use purposes.

Taiz et al. (2015) assert that when plants are exposed to salinity, their cytosolic concentrations of Na⁺ and Cl^– ions can reach more than 100mM. This leads to cytotoxism and protein denaturation as well as the destabilization of membranes. Additionally, when accumulations of Na⁺ in the leaves reaches toxic levels the ability of the plant to perform photosynthesis and other biosynthetic processes can become inhibited.

The main staple food crop in all of Asia is wheat (Triticum sp.). Wheat makes up the primary staple food for 30% of the global population (MuRahman et al., 2008). Another major food crop is barley which is of the Hordeum sp.

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Studies like those that were mentioned in the work of Flowers and Hajibagheri (2001) show that the concentrations of potassium ions decrease linearly as the concentrations of NaCl in a plant’s environment increase. The differences in the accumulation of different ions in the cytoplasm of plant cells greatly affect that plant’s capacity to survive and to grow. The capacity of the wheat and barley that were exposed to the higher concentrations of NaCl was clearly affected to the point where some of the seedlings were unable to emerge at all (Fig. X). The concentrations of K⁺ ions vary between 100-220 mol m^-3 in most plants that are classed as being glycophytic and under non-saline conditions the cytosol of higher plant cells contain less than 10mM Na⁺ ions, favoring higher concentrations of K⁺ ions instead (Taiz et al., 2015).

The problems with water uptake could be compounded as NaCl causes hardening of cell walls as well as inhibiting the water conductance of the plasma membrane. Tavili and Biniaz (2009) suggested that the effects that NaCl exposure has on the cell wall membrane impact upon the water potential of the cell and thus, the cell’s osmotic potential.

Areas of further study in regards to the improved production of staple food crops, such as wheat and barley, in saline environments could focus on various relationships of salt tolerant rhizobacterium with the crop species of interest. In research by Upadhyay and Singh (2013), several strains of soil microbes were used to inoculate wheat specimens that were kept in both the greenhouse environment and in the field. It was found that the salt-tolerant plant growth-promoting rhizobacterium (ST-PGPR) improved the growth and yield of wheat exposed to saline environments. Another interesting finding that is relevant to this report was that when the Bacillus subtilis bacterium was used to inoculate the wheat, Na content in the leaves was reduced by about 23% and that specimen seemed to outgrow the control.

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References

Flowers, TJ, Hajibagheri, MA (2001) Salinity tolerance in Hordeum vulgare: ion concentrations in root cells of cultivars differing in salt tolerance. Plant and Soil 231, 1-9.

 

Mujeeb-ur-Rahman, Soomro, UA, Zahoor-ul-Haq, M, Gul, S (2008) Effects of NaCl Salinity on Wheat (Triticum aestivum L.) Cultivars. World Journal of Agricultural Sciences 4, 398-403.

 

Taiz, L, Zeiger, E, Møller, IM, Murphy, AS (2015) ‘Plant physiology and development.’ (Sunderland, Massachusetts U.S.A. : Sinauer Associates, Inc:

 

Tavili, A, Biniaz, M (2009) Different Salts Effected on the Germination of Hordeum vulgare and Hordeum bulbosa. Pakistan Journal of Nutrition 8, 63-68.

 

Upadhyay, SK, Singh, DP (2014) Effect of salt-tolerant plant growth-promoting rhizobacteria on wheat plants and soil health in a saline environment. Plant Biology 17, 288-293.

Help keep our #CarbonPrice. Here’s how…

Pick out your political people and write to them! 

If you don’t know what to write copy and paste my letter (feel free to chop and change as you like).

<start>

Dear senators,

thank you all for contributing to the governance of our country. I could not begin to imagine what this must be like for you and I do not assume that this is anything but an immense task in itself.

Please do not ignore the catastrophe that we as a species are inflicting on the future of not only our children, but many, many future generations right across the planet.

Again, thank you for what you do and, again, I do not presume to have any idea of what your jobs must be like,
but, I am a scientist and I implore you to move towards the eradication of misinformation that seems to be spreading at an alarming rate in regard to the devastation that our excessive consumption and fossil fuel addiction has and continues to cause. The spreading of this scientific misinformation is not a form of free speech that must be protected. It is equivalent to convincing someone that if the continue to walk of a cliff the gravity of the earth and the laws of physics will not result in the abrupt ending of their existence.
We no longer have the luxury of time.
We must swiftly shift our stance as a people, immediately and actively focusing enormous efforts into decarbonising our economy.

You must all be aware that as the years go by the global understanding of the predicament that our civilisation is in will increase exponentially just as the severity of impacts on the earths biosphere by continued pollution will also.

It is simply inevitable that the futures of any groups or individuals who contribute to stalling or even attempting to stop progress being made in regards to significant protection of the earths atmosphere will be lost and destroyed.

<End>

Thank you for your time!

Sincerely,

L. Stafford.

 

Rising CO2 level affecting health of fish on the Great Barrier Reef.

Rising CO2 level affecting health of fish on the Great Barrier Reef..

Get used to heatwaves. El Niño events set to double.

Get used to heatwaves. El Niño events set to double.. #ClimateAction #AusPol #LeardBlockade

Graeme Pearman on Climate Change 2012

Graeme Pearman on Climate Change 2012

Leaving fossil fuel companies is straightforward and increasing popular, with major city governments like San Francisco and Seattle, churches like the Uniting Church of NSW & ACT, universities, individuals and more, all making the move.
carbon_price_agreement_briefing_july_2011

Why all is O.K…

Why all is O.K….

Climate Change and the Changing of the Social Climate

Tammemagi (2009, p.221) claims that “We  must use the solutions technology has provided us. Yet hybrid cars, smokestack scrubbers, carbon sequestration, and solar and wind power simply are not enough. As for the, as we saw in chapter 5, these green technologies will not be able to keep up with the population-economy treadmill.

To make progress in reducing global warming we must slow this treadmill. In other words, we need to slow down economic and population growth.

It will not be easy. There are strong forces at play, and societies have enormous momentum; like an ocean tanker, social directions cannot be changed quickly. Powerful corporations and organisations have a vested interest in maintaining the status quo. Furthermore many people are frightened of change and the uncertainty that comes with it.“

Tammemagi, H. Y. (2009). Air: our planet’s ailing atmosphere.

Solar Energy

Tammemagi (2009, p.197) claims that “Although solar energy can be used to heat homes and water directly, the most flexible use is with ‘photovoltaic cells’, which turn sunlight directly into electricity. The photoelectric effect was discovered in 1839 by a French scientist, Edmond Vecquerel. He found that when he exposed two different brass plates immersed in a liquid to sunlight, it produced a continuous electric current. In the late 1870s, English scientists found they could obtain the same result using selenium. It was not until 1954, however, that the first practical photovoltaic cell using silicon was developed at Bell Laboratories. Photovoltaic cells have many benefits: they are rugged, reliable, have no moving parts, can withstand extreme temperatures, are impervious to most corrosive chemicals, and give off no toxic emissions. Solar cells were first used, in the space program for sattelites where there is continuous sunshine.“

Tammemagi, H. Y. (2009). Air: our planet’s ailing atmosphere.

Renewable Energy

Tammemagi (2009, p.197) claims that “Renewable energy sources–such as windmills, solar panels, and hydro-electric generators, which produce no greenhouse gases–are an excellent way of combating global warming. The use of wind power, a seemingly simple and benign energy source, has increased rapidly in recent years as wind turbine technology. From 2000 to 2007, worldwide wind-power generating capacity increased from 18.000 MW to 92,000 MW, a five-fold increase. The world leader in wind power is Germany, followed by the United States, Spain, India, and Denmark. Denmark produces almost half of its electricity from wind.“

Tammemagi, H. Y. (2009). Air: our planet’s ailing atmosphere.