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Aims:. To grow sorghum and mungbeans in pots and undertake an experiment to record how much water the plants use. To observe growth and germination rates and analyse limiting factors to these observations.
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Aims: To grow sorghum and mungbeans in pots and undertake an experiment to record how much water the plants use. To observe growth and germination rates and analyse limiting factors to these observations. To apply knowledge gained to real life situations and suggest resolutions to future problems.
Hypothesis: The germination of the sorghum and mungbeans will occur rapidly due to the small environment in which they are planted in. Once germinated, the community of plants will have a fast growth rate but will depend on the limiting factors such as available sunlight, water and disease or pests. In terms of water usage, the mung bean plant will use more water as it has a greater surface area to volume ratio.
Prelude: Plants are a vital part in our existence. Plants, along with trees produce breathable oxygen for humans and other species on the planet. Without plants, Carbon dioxide levels in our atmosphere would be too high for anything to survive. Unfortunately, the increase in populations around the world has seen an increase in pollution and global warming, upsetting the natural cycle. These upsets create major problems such as disturbances to rain seasons and natural disasters. These problems will continue due to the ever growing populations and the need to expand the human empire. With expansion comes destruction to native forest and land and ofcourse, pollution. Knowing that the past can not be re-written, scientists have researched the effects humans have on plants and more specifically, how much water plants use. Research into two specific plant species have been conducted. These two species of plants are Sorghum and Mung beans.
OVERVIEW OF PLANTS Leaves Leaves make all the food for the plant. They do this by changing light, water and gases into food. This process is called photosynthesis.Stems and branchesStems and branches hold up the leaves and space the leaves out. This helps the plant to get the light it needs. Roots Roots help fix the plant to the soil or to other plants. Roots take in water and nutrients. Flowers Flowers contain the male and female parts of the plants. Successful pollination of the flower can result in the production of fruit and seeds. (www.caribbeanedu.com/kewl/science/science04d.asp)
LEAVES All leaves are responsible for: - absorbing the sun's rays - the majority of photosynthetic production - taking in carbon dioxide and releasing oxygen and water vapor (breathing) - removing waste products from the plant - using osmotic pressure to draw water up from the roots Parts of a leaf www.caribbeanedu.com/kewl/science/science04d.asp)
www.caribbeanedu.com/kewl/science/science04d.asp) STEMS All stems are responsible for: - Supporting leaves and flowers physically - Holding the leaves and flowers in the best position for food gathering and reproduction - Using xylem and phloem to transport materials from areas of plenty to areas of need in various parts of the plant - Storing nutrients for future use
ROOTS All roots are responsible for: - Anchoring the plant to the ground - Extracting water and minerals from the soil Primary root - the thickest . It grows downwards. Secondary roots - arise from the primary root. They are not as thick as the primary one. They go sideward. Root hairs - are minute filaments roots are covered with. They absorb water and nutrients from the soil. Root cap - is a kind of protection the roots end with. It is designed to drill the soil and it is able to guide the root growth by perceiving gravity. (www.caribbeanedu.com/kewl/science/science04d.asp)
PLANT ATTIRBUTES AND FACTORS Surface area to volume ratio Plants require minerals and nutrients to survive and in order to acquire these, they use diffusion through their roots and leaves. Diffusion is the process by which substance, or nutrients in this case, travel from an area of high concentration to low concentration across a membrane. The diffusion of water is known as osmosis and is found in plants as they absorb water from the soil. The effectiveness of this process is highly limited by the surface area versus the volume of the organism. If the surface area is large, and the volume small, then the greater opportunity for diffusion to take place. It comes as substances in the soil become absorbed into the roots and travel up the plant in order for it to photosynthesise. Nutrients and water become absorbed into the plant’s fine root hairs as previously mentioned. These fine hairs all add up to create a greater surface area for the plant giving it an optimum chance for survival. If these hairs become damaged, they do not functionproperly and limit the intake for the plant. These features along with other processes all control the health and growth of the plant. Transpiration is the process by which gaseous carbon dioxide is taken in by the plant and released as oxygen.
Background Information: Sorghum: Kingdom: Plantae Plants Subkingdom: Tracheobionta Vascular plants Superdivision: Spermatophyta Seed plants Division: Tracheophyta Class: Angiospermae Flowering Plants Subclass: Monocotyledons Order: Cyperales Family: Poaceae Grass family Genus: Sorghum Moench Sorghum Sorghum is a widely cultivated tropical cereal grass. It originated in Africa and in certain environments, can grow up to 3 metres tall. Sorghum is the fifth major cereal crop in the world. Sorghum has an extensive root system, waxy leaves and has the ability to temporarily stop growing in periods of drought, which means that it is able to withstand very arid conditions. Sorghum shares similarities with maize, and corn and therefore share physical structures. Its grains have a very similar structure to that of maize, although they are smaller and generally oval in shape. It has a horny and floury endosperm and a large fat-rich germ, but lack a true husk. Click on pictures
Background Information: Mung Bean: Kingdom: Plantae Plants Subkingdom: Tracheobionta Vascular plants Superdivision: Spermatophyta Seed plants Division: Magnoliophyta Flowering plants Class: Magnoliopsida Dicotyledons Subclass: Rosidae Order: Fabales Family: Fabaceae Pea family Genus: Vigna Savi Cowpea Species: Vigna radiata (L.) R. Wilczek Mung bean Variety: Vigna radiata (L.) R. Wilczek var. radiata Mung bean The Mung Bean is part of a large family and consists of many different types of beans, legumes and peas. In some cases, it is difficult to classify mung beans as they have striking characteristics similar to the common pea. There are many different species of mung bean each having a unique flower and can be grown almost anywhere. Because they produce a bean and not a husk like sorghum, it uses more water and nutrients to grow the bean and therefore requires an excessive amount of water. Because mung beans are part of the legume family, they are vital when it comes to the nitrogen cycle. As they perform nitrification where they shed leaves after converting excess nitrogen into nitrates and nitrites entering the soil through the shed leaves. These nitrates and nitrites then perform their special tasks.
Animated cycle Nitrogen Cycle and Plants: The nitrogen cycle represents one of the most important nutrient cycles found in terrestrial ecosystems. Nitrogen is used by living organisms to produce a number of complex organic molecules like amino acids, proteins, and nucleic acids. The store of nitrogen found in the atmosphere, where it exists as a gas (mainly N2), plays an important role for life. This store is about one million times larger than the total nitrogen contained in living organisms. Other major stores of nitrogen include organic matter in soil and the oceans. Despite its abundance in the atmosphere, nitrogen is often the most limiting nutrient for plant growth. This problem occurs because most plants can only take up nitrogen in two solid forms: ammonium ion (NH4+ ) and the ion nitrate (NO3- ). Most plants obtain the nitrogen they need as inorganic nitrate from the soil. Ammonium is used less by plants for uptake because in large concentrations it is extremely toxic. Animals receive the required nitrogen they need for metabolism, growth, and reproduction by the consumption of living or dead organic matter containing molecules composed partially of nitrogen. (www.physicalgeography.net/fundamentals/9s.html)
Photosynthesis: Photosynthesis is an important biochemical process in which plants, algae, and some bacteria convert the energy of sunlight to chemical energy. The chemical energy is used to drive synthetic reactions such as the formation of sugars or the fixation of nitrogen into amino acids, the building blocks for protein synthesis. Ultimately, nearly all living things depend on energy produced from photosynthesis for their nourishment, making it vital to life on Earth. It is also responsible for producing the oxygen that makes up a large portion of the Earth's atmosphere. Organisms that produce energy through photosynthesis are called photoautotrophs. Plants are the most visible representatives of photoautotrophs, but it should be emphasized that bacteria and algae also contribute to the conversion of free energy into usable energy. www.caribbeanedu.com/kewl/science/science04d.asp)
PHOTOSYNTHESIS 6H2O + 6CO2 --> C6H12O6+ 6O2 CARBON DIOXIDE (CO2) WATER (H20) OXYGEN (O2) SUCROSE (C6H1206)
Materials: • Free planting kits provided by DPI&F Hermitage Research Station: • 1 x packet of sorghum seed. • 1 x packet of mung bean seed. • Reference material. • Own Choice Items: • 8 x empty plastic 2.4 ‘Berri’ juice containers or 3 litre ‘golden circle’ juice containers or • 3 litre milk containers (with caps). • Note: Please don’t use containers with long necks as they will not stand up properly for the • experiment. • Extra empty plastic containers (as above) if adding extra garden plants for a • comparison. (not compulsory). • A set of scales (that give readings in grams would be ideal). • 500ml or 1 litre measuring jug. • A small funnel to water the pots through a small opening. • Scissors/knife for cutting containers. • Small amount of newspaper. • Soil from your school garden/paddock. • Masking tape and permanent marker to label containers. • Plastic shopping bags to cut up and cover your containers when required
Procedure: • Preparing pots for planting: • Mark each container 12 cm from bottom and continue all around the container. • Cut all 8 containers at this 12 cm mark (keep tidy and neat) • Place the top half of the container inside the bottom half. • Make some holes in the bottom half of the containers so any excess water can drain through. • In each of the 8 containers, place a small ball of scrunched newspaper at the opening of the container so the soil won’t fall out. • Fill the 8 containers evenly with good paddock/garden soil (until there is about 4cms left to the top of the container). • Water each container until soil is saturated (note this will vary depending on soil quality or type)
Procedure: Planting: • Draw a circle into the soil of each container about 2 cm in from the outside of the containers. • Evenly spread 6 sorghum seeds around this circle in four of the containers and cover them with around 2cm of soil • Label these four containers “sorghum 1 - 4”. • Repeat this process with the mung beans. There should now be eight labelled containers: • Sorghum 1 • Sorghum 2 • Sorghum 3 • Sorghum 4 • Mung bean 1 • Mung bean 2 • Mung bean 3 • Mung bean 4 • Place pots somewhere warm (preferably outside in a sunny spot, protected from wind with some shelter from rain if possible, but not in the shade). Plants will grow best in full sun, but you can grow them in a greenhouse if need be. • Note germination rates and record any irregularities.
Procedure: • The Experiment: • Once all the plants have grown for about 3 weeks, you need to pull some plants out until you are left with 1 healthy plant per container. • On the same day you thin the plants back to one per container, water each container to full capacity until the soil is fully wet and water begins seeping through the bottom of the containers. Do not water for 24 hours. • Once 24 hours have passed, carefully remove the top half of the containers from their bases and screw on the lids. Sit the top halves back into the bottom halves of the juice containers. • Seal the top of the container to make sure no water is being evaporated from the soil surface. • Cut the plastic shopping bags into two square pieces that will fit over your container and place them side by side over the containers, just leaving a very small gap for the stem of the plant to poke through. • Weigh each pot and record the weight (this is the starting weight). • Leave the plants for one week and observe plant growth • In a week’s time weigh each plant again and record the new weight in your journal. Work out the difference in weight from the starting weight. • Leave the plant sit for another week and observe plant growth.
Procedure: • Plant Pressing: • After the plants have grown for about 6-10 weeks, remove plants and washed off any excess soil left on the roots. • Weigh the plants making sure that none of the roots were damaged or taken off. This will be the wet weight. • Once all weighed, place each individual plant between roughly three sheet of newspaper and place heavy weight on it. • Let stand for two days. • If paper is wet, change paper. • After a week, weigh the plants again. This will be the dry weight. • Observe the differences.
Click on pictures This graph clearly shows the growth rates of the sorghum in the experiment. It shows that during the first few days, the growth rate was steady but fluctuated a little from there onwards indicating watering patterns and a change in environment. Possibly, this rise and fall could have been triggered by the move from the classroom to the greenhouse. Click on pictures The graph shows the water input of both plants and illustrates that both received the same amount throughout the experiment. This graph does not account for rainfall. Click on pictures This graph shows the water run off in the bottom of the containers. It is evident that when comparing the input from the output, one can see that when the water is added, roughly around the same time, water seeps through into the run off section of the containers.
