Science by Email 29 June 2012

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	29 June 2012
News: Science on the farm By Patrick Mahony Collars such as these are used to monitor methane emissions from livestock. Scientific research can be hard work. While there is the occasional flash of inspiration or accidental discovery, scientific advancements are the often the result of long hard study and a series of experiments.                                     Scientists conduct research in a number of ways. They might set up an experiment in a lab, or analyse data from a radio telescope, or construct theoretical computer models. Depending on the field of research, scientists will combine different types of research. Ultimately, they use their results to develop theories about how the world works. An important area of research in Australia is agricultural research. Agriculture is a significant contributor to greenhouse gas emissions, so scientists from a number of organisations are researching ways to reduce them. So how do agricultural scientists conduct their research? Large-scale commercial farms are not something that can be replicated in an ordinary laboratory. Scientists can construct models based on various observations and data, but the model is only valuable if it accurately reflects what really goes on out in the paddock. In order to make sure their work is valid and conclusions accurate, agricultural scientists use test farms, or demonstration farms. Test farms can be used to research plant crops, animal husbandry or other aspects of farming. On some demonstration farms, cattle and other livestock go about their daily business, just as they would on a regular farm. Unlike a regular farm, these animals are having their methane emissions monitored. Techniques include laser detection methods and special collars. Scientists can change a variable, such as the animals’ diet, then measure the effect it has on their methane emissions. This means they can test their hypotheses with real-life data. The Australian Government Department of Agriculture, Fisheries and Forestry funds research at a number of test farms around Australia as part of its Climate Change Research Program. For example, researchers at Trevenna, on a University of New England test farm, recently showed that increasing soil fertility and sheep feed efficiency results in less greenhouse gas emissions. More information DAFF: Livestock emissions CSIRO: Greenhouse gases in Australian agriculture Careers link Agricultural scientist
You will need these materials.   Line one container with paper towel, and sprinkle a layer of seeds on it.   Put some soil in the other three containers and add seeds.   Put lids on the containers and water with the appropriate mixtures.   Try this: How does your garden grow? Part 3: Fertiliser Safety: This activity uses chemicals. Read and follow all safety advice on the packets. See the CSIRO Education safety page for more information. You will need Cress or mustard seeds (available from garden stores) Paper towels Plastic containers with lids Spray bottles Soil or compost 2 types of fertiliser Marker Buckets What to do Line a plastic container with paper towel. Place a layer of soil about 1 cm thick in another 3 containers. Label the container lined with paper towel as ‘no fertiliser or soil’. Label another container ‘soil only’. Label each remaining container with the name of a fertiliser. Sprinkle a layer of seeds in each container. Follow the instructions on each fertiliser packet. Dissolve each fertiliser in an appropriate amount of water, with each mixed in a different bucket. Carefully pour each bucket’s solution into a different spray bottle. Label each spray bottle with the name of the appropriate fertiliser. Fill another spray bottle with tap water. Label this bottle ‘tap water’. Spray liquid from each bottle into the corresponding seed container so the soil is well moistened. Use the ‘tap water’ bottle to water the container with no fertiliser or soil and the container with soil only. Place lids on the containers and put them in a bright, well-lit place. Observe the seeds a few times a day and spray them with tap water to keep them moist. Check on your seeds every day. Once they have sprouted, you can keep remove the lids. Observe any differences between the containers. When your sprouts are fully grown you can pick, rinse and eat them! What’s happening? The most basic things plants need to sprout and grow are sunlight, water and carbon dioxide for photosynthesis. However, there are a few other elements, such as nitrogen, phosphorus and potassium that they need to grow into healthy plants. Soil is a complex mixture that contains many components, which can include clay, sand, minerals, water and organic material. Many plants obtain a number of the elements they need to grow healthy and strong from soil. Sometimes the soil doesn’t have all the nutrients a plant needs and they may not grow properly. Most fertilisers contain compounds that include nitrogen, phosphorus or potassium, and sometimes two or all three. By adding these to the soil, plants are able to get more of the nutrients they need. Using fertiliser may make plants grow faster, bigger or stronger than plants grown without fertiliser. Applications Fertilisers are useful for increasing crop yields. By using different types of fertiliser, farmers may be able to increase the amount of grain, fruit or vegetables grown on their land.   Fertiliser use can, however, contribute to greenhouse gas emissions. For example, if the amount of nitrogen added to soil in the form of fertiliser is greater than the amount that can be absorbed by the crop, extra nitrogen may be converted by bacteria into nitrous oxide, a greenhouse gas. Nitrous oxide emissions can be reduced in a number of ways, including by adding lime (a calcium compound) to soil and by developing more efficient fertilisers. By Patrick Mahony This is the third activity in the series ‘How does your garden grow?’ Try the other activities in this series, on water and temperature. More information Plant nutrients in the soil DAFF: Nitrous oxide emissions Fertilisers and the environment View the online version Thank you DAFF! The Department of Agriculture, Fisheries and Forestry (DAFF) have sponsored Science by Email since 2010. Support from sponsors enables us to provide Science by Email to our readers for free. This is the last issue of Science by Email to be sponsored by DAFF. The Science by Email team would like to thank DAFF for their generous support over the past two years. Quiz questions 1. In physics, what can be reflected, refracted and diffracted? 2. What illness is caused mainly by rhinovirus? 3. There are two chemical elements that end in the letter ‘c’ – name one of them. 4. What is the most common ABO blood type in Australia? 5. What was Lonesome George? Did you know? Lyrebirds are excellent mimics. According to research from the Australian National University, lyrebirds are so convincing, some birds struggle to tell the difference between the calls of their own species, and the lyrebirds’ imitations. Websites   See it! Check out these pictures of some of the oldest trees on the planet. Watch it! Follow the construction of CSIRO’s new marine research vessel, the RV Investigator. Quiz answers 1. Waves can be reflected, refracted and diffracted. 2. Rhinovirus is the main cause of the common cold. 3. Zinc and arsenic are the two elements that end in ‘c’. 4. The most common ABO blood type in Australia is type O blood. 5. Lonesome George was the last Pinta Island tortoise, a subspecies of giant tortoise symbolic of the Galapagos. His death this week means the subspecies is now extinct. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Jasmine Leong| Manage your subscription | FAQ

 

 

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