Plants that grow in water habitats are called Aquatic plants. A few common examples of these are the seaweeds and water lilies. They have unique characteristics for them to adapt in marine environment. So what are the parts of an aquatic plant? And what are their uses? Aquatic plants have a thin cuticle. Cuticles primarily discourage water loss; thus most hydrophytes have no need for cuticles. They have the stomata that are open most of time because water is abundant and therefore there is no need for it to be retained in the plant. This means that guard cells on the stomata are generally inactive.
They have an increased number of stomata, which can be on either side of leaves. They possess a less rigid structure since water pressure supports them. Flat leaves on surface plants are for flotation. Those that are not for the surface have air sacs for flotation instead. Aquatic plants have two kinds of roots one is the smaller roots where water can diffuse directly into leaves. And the other, feathery roots where it does not need to support the plant. But there are also specialized roots able to take in oxygen. So what do aquatic plants need to grow?
The first consideration would of course be the water in which the plants will grow. The kind of water you that you have and the temperature in you aquarium both play an important part in your plant life. Most aquarium plants found in marshes do well in warmer temperature, and 75 degrees Fahrenheit is usually the ideal temperature for most tropical plants. It is seen that plants flourish even better if the heat generated is from the bottom so that their roots get enough heat. This can be achieved by placing a submersible heater right at the bottom of the aquarium where the water meets gravel.
Another way to keep your plant life healthy is by leaving their roots undisturbed. When you are cleaning your aquarium or changing water, care must therefore be taken so that the roots do not get disturbed. Since photosynthesis takes place in the presence of light, light is a necessity for healthy plants. Natural sunlight is made up of a number of light waves that have different wavelengths. The plant pigment chlorophyll will absorb only certain light waves. Sunlight will promote the growth of algae. Long exposure to sunlight will also heat up the water. Artificial ight is therefore more advisable for plants growing in an aquarium. Full spectrum or broad spectrum fluorescent light is best suited for plant growth. Aquariums usually need about 1. 5 watts of light per gallon of water and about 12 hours of light per day. If the aquarium is deep, additional wattage will be needed, as well as the need to keep the light on for longer hours. Using light colored gravel is a good way to create a light bottom for a deep aquarium. The wattage of light required for healthy growth in plants is also species dependent. In nature, plants are continuously receiving nourishment from their surroundings.
Aquarium plants derive nourishment from the substrate. There are different varieties of substrate available now, but for the beginner a substrate that is low maintenance and stable is the ideal choice. A substrate that needs constant watching and gets messy is not recommended. Similarly, a substrate that is capable of changing the water chemistry is also something to keep away from. This kind of substrate will require constant monitoring of the water. Organic substrates, rich in nutrients, could possibly mess with the water quality and give out excess nutrients.
Since the substrate lies at the very bottom of the aquarium, it is difficult to be changed once the aquarium has been established. Ideally, a substrate that is inert and that will not alter your water chemistry should be selected. The perfect substrate will also have a high Cation Exchange Capacity which refers to the ability of the medium to absorb nutrient ions. This means that your substrate will hold on to the nutrients and make them available to plant roots. In this respect, sand is a very poor substrate. It has none of the qualities described above and it can be used only as an anchor for your plants.
Gravel will usually also have a very low Cation Exchange Capacity and some types of gravel will alter the water chemistry. Fluorite is a great substrate. Though it is a bit expensive, it is very nice looking and it is rich in nutrients. It does not get soft when it is in water and it also has iron and other trace elements that are good for plants. Vermiculite is a soil additive that is very rich in nutrients, but it is also very light and needs to be placed below a layer of heaver material. Otherwise, it will start floating around which causes the water to become cloudy.
Using suitable additives in the substrate used will be beneficial to plants. Commercially available products help to induce plant growth. Some of these are to be mixed in with water, while others need to be pushed in near the roots of the plant. Both micro and macro nutrients are required by plants for growth. Macronutrients include nitrates, sulfates and phosphates. The plant requires these in large quantities. If a lot of macronutrients are introduced to the aquarium, an undesirable ‘algae bloom’ could be lead to. Micronutrients are nutrients required in trace amounts.
Nutrients like iron, copper, zinc and calcium are some of these. Excessive amounts of these can prove harmful for the plants. Carbon Dioxide is the most important nutrient that a plant needs. Carbon dioxide levels in water should be between 5-15 Mg/l. The use of aerators is also a factor in the growth of plants. Constantly keeping air pumps or bubblers on will deplete the carbon dioxide levels in the water. On the other hand, aerators are needed to keep the water rich in oxygen. A deficiency in nitrogen and sulfur is indicated when the leaves turn yellow faster than usual.
If the leaves seem to be very brittle, more iron is needed in the aquarium. Over fertilization may lead to problems as well. The leaves getting yellow spots can indicate an excess of iron, zinc or copper. Almost any kind of filtration system will do for plants. Only a few things have to be kept in mind. Constant use of aerators should be avoided. Use a filtration system that will filter out floating particles. These particles will block sunlight and also form a deposit on plant leaves. The filtration should not produce too much of water disturbance, as this will deplete Carbon Dioxide levels.
On the other hand, the filtration must create some currents in the water, as this will help easy circulation of nutrients. The Hydrilla, the group’s chosen aquatic plant has unique characteristics that enables it to adapt to different habitats in order for it to grow easily. There is only one species of Hydrilla in the world, the Hydrilla Verticillata which originated from India and Korea. This aquatic plant can grow in almost any type of freshwater bodies: springs, lakes, marshes, ditches, rivers and/or tidal zones. It can grow an inch or more per day when conditions are favorable. Its slender stems can reach up to 25 feet long.
A single tuber of it can develop to produce more than 6,000 new tubers per m2 (Sutton et al. 1992). A tuber is a potato-like structure of the hydrilla that is attached to the roots in the mud. Low light compensation and saturation points and low CO2 compensation point make it a competitive plant because it can start growing in low light before other plants do (Van et al. 1976; Bowes 1977). In fact, it can grow even in only 1% of full sunlight. Its temperature tolerance is great: hydrilla is somewhat winter-hardy; its optimum growth temperature is 20-27o C (68-81o F) and its maximum temperature is 30o C (86o F) (Kasselmann 1995).
The Hydrilla in the United States is actually considered as a weed. The Americans are having trouble with the aquatic plant since it greatly slows water flow and clogs irrigation and flood-control canals; in Florida, large mats of fragments collect at culverts and clog essential water control pumping stations. The Hydrilla was called a weed because it may grow in only a few inches of water, or in water more than 20 feet deep and may grow in oligotrophic (low nutrient) to eutrophic (high nutrient) conditions. With these, we experiment on the effect of liquid fertilizers with it.
Upon hearing the word “liquid fertilizer” is it obvious that the word itself is self-explanatory. It’s plant fertilizer that takes up liquid form rather than solid. Just like any other common fertilizer, liquid fertilizers help contribute to the growth of plants. Generally, liquid fertilizers are highly concentrated formulations that contain readily available nutrients that bolster soil microorganisms and improve soil structure and composition. Liquid fertilizers in general require more frequent applications compared to commercial fertilizers because it is easier to use.
Because of its liquid consistency, liquid fertilizers allow more uniform application, making it easier to apply fertilizer equally to the plants. Also, liquid fertilizers can work in conjunction with a variety of other pesticides (certain compatible pesticides make, “weed and feed” programs possible). Although the liquid fertilizer can promote plant growth, it can also kill the plant if the pH level of the water mixed with the fertilizer is not between 6. 5-7. 0 pH. Compared to organic fertilizers, liquid fertilizers only differ in form.
Most of the chemicals/components that build up liquid fertilizers are similar to that of organic fertilizers. Generally, most liquid fertilizers include nitrogenous fertilizers, anhydrous liquid ammonia, aqueous ammonia, ammoniates, concentrated solution of ammonium nitrate and urea and complex fertilizers containing two or three basic plant food elements (nitrogen, phosphorous and potassium) in various proportions. Just like other fertilizers, liquid fertilizers are mainly composed of Nitrogen, Phosphorus and Potassium compounds.
Fertilizers, in general replace the chemical components that are taken from the soil by growing plants. They are also designed to improve on the growing potential of the soil. And it is highly the same for liquid fertilizers. They supply plant nutrients and/or amend soil fertility4, which is somehow self-explanatory on why it’s called “fertilizer”. They also ensure that the chemical elements are supplied to the plant so that it can grow. RESULTS The experimentation is mainly focused on the effects of different factors on the growth of the hydrilla.
There would be three sets of the experiment all having enough sunlight exposure and amount of water. One (A) is set as constant which has plain water, another, named as set B has bleach (tide) and lastly, set C has a vinegar mixture. WaterTideVinegar Day 1-4No changeNo changeNo change Day 5-8No changeSmall green particles fallingSour smell Day 9-12No changeAir sacs seem deflatedAir sacs seem deflated Day 13-16No changeThe hydrilla turned brownishThe hydrilla turned brownish The table above, shows the effects of different ph levels to the physical appearance of hydrilla as days are counted.
In the constant set, the hydrilla appears to be healthy since it’s appearance remained stable. On the other hand, the sets that had a ph level of less or more than 7, the plant reacted bitterly towards the environment thus the result as shown above. The diagram shown on the next page illustrates the growth of the aquatic plant in length as to it’s different environment due to varying ph levels. The ratio used for the growth is 1:2 inches. The graph suggests that as the days precede in set A (water), the plant grows into a steady pace. But in set B (bleach) and set C (vinegar), the plant stopped growing after four days.
Summarizing, in the duration of two weeks and two days, both aquatic plants that were submerged in the basic and acidic solution wilted and died. This states that the ph level of the environment greatly affects the growth of the Hydrilla Verticillata. In addition, it is necessary for the milieu it is in to be a fresh water for the plant to survive.
RECOMMENDATIONS
This Investigative Project proposes the growth of aquatic plants concerning the different factors that may affect the growth of the plant Hydrilla, scientifically known as Hydrilla verticillata. The experiment was mainly focused on the ph levels of the water and how this may influence the augmentation of the specimen. In the assessing of the factors that affects an Aquatic Plant, in this experiment, the group used the hydrilla, a freshwater plant, to conduct a research or gathering of information that may influence the growth of marine plants in general. Through this experiment, the group gained knowledge that ph levels of the water could affect the health and growth of the plant, hydrilla. When growing the hydrilla, the ph level of the water should be neutral or ph7 for the plant to grow in condition.
This group of researchers believes that through the experiment on hydrilla, they may give additional information in contribution to knowledge in biology. The effects of water pollution in water species is very great as clearly seen with the change of ph level is connected to the health of the plant as shown in the group’s investigative project. The experiment could have been better if the main focus was expanded. This would include the amount of sunlight exposure given to a set could have varied and the temperature of the water was shifted in each set.
This, of course, would involve more of the specimen used to be able to compare different factors from one another.
Sources:
1. http://www. ecochem. com/t_faq5. html 2. http://www. oldhouseweb. com/gardening/liquid-fertilizers. shtml 3. http://www. encyclopedia2. thefreedictionary. com/Liquid+Fertilizers 4. http://en. wikipedia. org/wiki/Fertilizer 5. http://www. onlinegardenertips. com/Fertilizer/How-Does-Fertilizer-Work. html 6. Center for aquatic and invasive plants, university of florida, IFAS. Obtained from http://plants. ifas. ufl. edu/node/183
