NAME : SYASYA SYARAFANA SYAUQINA BINTI MUHAMAD ADAM LIM

I/C : 951219-10-6058

GROUP : ALUK 11

STUDENT I/D : 1311171167

TITLE : INVESTIGATING PLANT MINERAL DEFICIENCIES

DATE OF EXPERIMENT : 20 FEBRUARY 2014

DATE OF SUBMISSION : 7 MARCH 2014

LECTURE : MADAM LILI SYAHANI BINTI RUSLI

OBJECTIVE

To investigate the effect of plant mineral deficiencies.

To develop problem solving and experimental skills, for example, information is accurately

processed, experimental procedures are planned, designed and evaluated properly, and

producing valid results and recording results.

To develop careful observing skills on the development changes occurred on Lemna leaves.

INTRODUCTION

This experiment is conducted by using Lemna and also known as duckweed. Duckweeds are one

of the smallest of the flowering plants. It is free floating and aquatic living plants that can form a

rapidly-expanding mat of foliage, approximately to 1/4” tall on still water surfaces. This plant

species can be found throughout the world. It is named as duckweed because ducks as well as

waterfowl love to consume it. Fish such as goldfish or carp also eat the plants and can be a vital

component for population control in ornamental ponds. Lemna is also a significant food source

for muskrats, beaver, birds and small aquatic animals such as frogs. It is also a well-known

addition to water gardens and ponds where it not only provides attractive foliage cover but also

minimize the growth of algae. The appearance of Lemna can be described as oval rounded,

flattened green frond with a single downward-trailing root.

Plants are ubiquitous organisms that can absorb nutrients and water through their root system,

as well as carbon dioxide from the atmosphere. Soil quality and climate also play a significant

role as they are the major determination of distribution and growth. The combination of soil

nutrients, water and carbon dioxide, along with sunlight, enables plants to grow. Many

requirements must be met and events must be coordinate by plants in order to develop into

mature, fruit-bearing plants. Plants require water, carbon dioxide and sunlight to synthesis

carbohydrates or also known as food during photosynthesis. Plants also need additional

elements to synthesis nutrients and other organic substances. There are sixteen chemical

elements that are significant for the development and survival of plats. These sixteen chemicals

are divided into two major groups which are mineral and non-mineral.

The non-mineral nutrients are carbon (C), hydrogen (H) and oxygen (O). These type of nutrients

can be found in water and air. These elements are vital in the process of photosynthesis in which

plants use energy from the sunlight and convert them into carbon dioxide and water so that the

plants can produce starches and sugars. The starches and sugars are the plant’s food. Since

plants receive carbon, hydrogen and oxygen from the air and water, there is little farmers and

gardeners can do to control these how much of these non-mineral nutrients a plan can use.

Also, deficiency in these nutrients rarely occurs and become the least of farmers and gardeners

concern. Apart from that, they are also the most abundant elements found in plant and form

major ingredients of organic compounds, most of which are carbohydrates. The first non-

mineral nutrient, carbon (C), is essential to form carbohydrates, proteins, nucleic acid and many

other compounds. On average, the dry weight (excluding water) of a cell is 50 percent carbon,

making it a key part of plant biomolecules. Hydrogen (H), on the one hand is necessary for

cellular respiration in which plants use oxygen to store energy in the form of ATP. Both

hydrogen and oxygen are also part of many organic compounds and form water as well.

There are thirteen mineral nutrients, which come from the soil, are dissolved in water and taken

up by plants via active transport process, against the concentration gradient. Mineral nutrients

are not always enough in the soil for plants to grow healthy. Therefore, most of the farmers and

gardeners add fertilizer that contains nutrients to the soil. The mineral nutrients are divided into

two groups which are macronutrients and micronutrients. Macronutrients are elements

required by plant in relatively large amounts whilst micronutrients are elements required by

plants in a small quantity. Macronutrients can further be broken into two groups; primary and

secondary nutrients. The primary nutrients consist of nitrogen (N), phosphorus (P), and

potassium (P). These major nutrients usually are lacking from the soil first because plants use

large amounts for their growth and survival. The secondary nutrients are calcium (Ca),

magnesium (Mg) and sulfur (S). There are usually enough of these nutrients in the soil thus

fertilizer is not always needed. Furthermore, large amount of calcium and magnesium are added

when lime is applied to acidic soils. Sulfur is also usually found in sufficient amounts from the

slow decomposition of soil organic matter, which is also one of the important reasons for not

throwing out grass clipping and leaves. The micronutrients of mineral nutrients are boron (B),

copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn). Recycling

organic matter such as grass clippings and tree leaves is an excellent way of providing

micronutrients as well as macronutrients to grow plants.

Each mineral nutrient has their own functions and the results can be devastating if there is a lack

of this nutrients in the plants. Nitrogen is a part of all living cells and it is a vital part of all

proteins, enzymes and metabolic processes involved in the synthesis and transfer of energy.

Nitrogen is also a part of chlorophyll, the green pigments of the plants, that is responsible for

the plants to carry out photosynthesis process. It also aids plants with rapid growth, increasing

the production of seed and fruits as well as improving the quality of leaves and forage crops.

Nitrogen often comes from fertilizer application and from the air. Similar with nitrogen,

phosphorus plays an important role in the process of photosynthesis. It assists in the

transformation of solar or light energy into chemical energy. It is also involved in the formation

of all oils, sugars, starches and others. Besides that, it encourages blooming and root growth as

well as effects blooming and root growth. Phosphorus can be found in fertilizer, bone meal and

superphosphate. On the one hand, potassium is absorbed by plants in large amounts than any

other mineral element available except nitrogen and, in some cases, calcium. It helps the plants

in many ways including in the building of protein, photosynthesis, fruit quality and reduction of

diseases. Potassium can be supplied to plants by soil minerals, organic materials and fertilizer.

On the other hand, calcium is a crucial part of plant cell wall structure. It provides for normal

transport and retention of other elements as well as strength in the plants. It also functions to

counteract the effect of alkali salts and organic acids within a plant. The source of calcium can be

obtained from dolomitic lime, gypsum and superphosphate. Magnesium is one part of the

chlorophyll in all green plants and it is indispensable for the process of photosynthesis. It also

helps activate many plant enzymes that required for the plant growth. The source of magnesium

for plants can be obtained in soil minerals, organic materials, fertilizers and dolomitic limestone.

The last macronutrient is sulfur which is vital plant food for production of protein. It stimulates

the activity and development of enzyme and vitamins. It also important as it helps to improve

roots growth and seed production. It aids in the chlorophyll production, vigorous plant growth

and resistance to cold. Sulfur can be supplied to soil from rainwater. It is also added in fertilizers

as an impurity, especially the lower grade fertilizers.

Micronutrients are also important to all plants although they are only required in a small

proportion. Boron aids in the production of sugar and carbohydrates as well as in the use of

nutrients and regulates other nutrients. It is also vital for seed and fruit development. The

source of boron can be found in organic matter and borax. Furthermore, copper is significant for

reproductive growth and it helps in root metabolism and utilization of proteins. Besides that,

chloride helps in plant metabolism and can be easily found in the soil. On the one hand, iron is

indispensable for the formation of chlorophyll and the source of iron can obtained from the soil,

iron sulfate and iron chelate. Manganese, on the other hand, plays an important role with

enzyme systems that involved in the breakdown of carbohydrates and nitrogen metabolism.

Molybdenum also helps in the use of nitrogen. Last but not least, zinc is critical for the

transformation of carbohydrates as it regulates the consumption of sugars. It is also part of the

enzyme system which regulates plant growth. The source of zinc is soil, zinc oxide, zinc sulfate

and zinc chelate. Deficiency in any of these nutrients, particularly the macronutrients, can

adversely affect the growth of the plants. A lack of these specific nutrients can cause stunted

growth, slow growth or chlorosis, in which the synthesis of chlorophyll is inhibited, results in

pale yellow leaves. Extreme deficiency can result in leaves showing signs of cell death. Below are

the effects of deficiency.

Macronutrient Effects of Deficiency Micronutrient Effects of DeficiencyNitrogen Stunted growth

ChlorosisBoron Death of terminal buds

Abnormal plant growth Leaves become thick,

curled and brittlePhosphate Poor root growth

Formation of dull, dark green leaves

Red or purple spots on old leaves

Copper Death of young shoot tips

Brown spots appear on terminal leaves

Plants are stuntedPotassium Reduced protein

synthesis Yellow-edged leaves Premature plants death

Iron Yellowing of young leaves

Calcium Stunted growth Leaves become

distorted and cupped Areas between leaf

veins become yellow

Manganese A network of green veins on a light green background

Brown or grey spots between the veins

Magnesium Chlorosis Red spots on the leaf

surfaces Leaves become cupped

Molybdenum Chlorosis in the areas between the veins of mature leaves

Pale green leaves Reduction in crop yields

Sulfur General yellowing of the affected leaves or the entire plants

Zinc Mottled leaves with irregular areas of chlorosis

Figure 1: The effects of deficiency of plants

PROBLEM STATEMENT

What are the effects of growth of Lemna in different range of nutrient solution?

HYPOTHESIS

Lemna sp in the normal solution which contain all the nutrients needed by the plants

(potassium, magnesium, sulfate, calcium, iron, nitrate, and phosphate) has the highest number

of plantlets after 2 weeks.

VARIABLES

Types of Variables Ways To Control the Variables

Manipulated variable: Culture solution of

Lemna sp.

Use different culture solution of Lemna sp.

which are all nutrients presents, lacking

nitrate, lacking potassium, lacking calcium,

lacking phosphate, lacking sulfur, lacking

magnesium and distilled water.

Responding variable: Growth and appearance

of Lemna sp.

The growth and appearance of Lemna sp. are

recorded in a table such as number of roots,

number of leaves, shape of leaves and colour

of leaves.

Constant variable:

(i) Volume of cultured solution

(ii) Surrounding condition

The volume of cultures solution in each Petri

dish is fixed which is 15cm3

The surrounding environment such as light

intensity, humidity, temperature, solution pH

is remained constant

APPARATUS

8 Petri dishes, measuring cylinders, beakers, droppers, forceps

MATERIALS

Label stickers, tissue paper, Lemna sp., nutrient solutions (all nutrients present, lacking nitrate,

lacking potassium, lacking calcium, lacking phosphate, lacking iron, lacking magnesium, distilled

water)

PROCEDURE

A. Procedure 1: Preparation of culture solutions

1. The Petri dishes are rinsed with distilled water and clean dry with tissue paper to

prevent any foreign substances, microorganism or pathogens in the dish.

2. 15cm3 of each culture solution is taken out from bottles by dropper and measured in

the small measuring cylinder.

3. Each culture solution is poured into different Petri dish. The Petri dish is labeled with

sticker.

4. The Petri dishes are covered with lid for a while.

B. Procedure 2: Preparation of Lemna sp.

1. Each Petri dish is opened and five Lemna sp with almost similar appearance are

scattered into each Petri dish.

2. The Petri dishes are then covered with lid and they are placed at the same place and

environment.

C. Procedure 3: preparation of observation of growth and appearances of Lemna sp.

1. The Petri dishes are placed at the back of the classroom and leave about 11 days.

2. The intervals of 2 days are used and it continued until 11th days.

3. The number of leaves, the number of roots, the shape of the leaves and the colour of

leaves are calculated during the observation.

4. The results are recorded in the table and interpretation of data is analyzed to make

comparison between each Lemna sp.

RESULT

Type of solution Day Number of roots Number of leaves

Colour of leaves

All nutrients present

1 0 1 Green

3 0 1 Green

5 0 1 Green

7 0 1 Yellowish green

9 0 1 Yellowish green

11 0 1 Yellow

Lacking nitrogen 1 0 1 Green

3 0 1 Green

5 0 1 Yellowish green

7 0 1 Yellowish green

9 0 1 Yellow

11 0 1 Yellow

Lacking phosphate

1 0 1 Green

3 0 1 Green

5 0 1 Yellowish green

7 0 1 Yellowish green

9 0 1 Yellow

11 0 1 Yellow

Lacking potassium

1 0 1 Green

3 0 1 Green

5 0 1 Yellowish green

7 0 1 Yellowish green

9 0 1 Yellow

11 0 1 Yellow

Lacking magnesium

1 0 1 Green

3 0 1 Green

5 0 1 Yellowish green

7 0 1 Yellowish green

9 0 1 Yellow

11 0 1 Yellow

Lacking calcium 1 0 1 Green

3 0 1 Green

5 0 1 Yellowish green

7 0 1 Yellowish green

9 0 1 Yellow

11 0 1 Yellow

Distilled water 1 0 1 Green

3 0 1 Yellowish green

5 0 1 Yellowish green

7 0 1 Yellow

9 0 1 Yellow

11 0 1 Yellow

Lacking Sulfur 1 0 1 Green

3 0 1 Yellowish green

5 0 1 Yellowish green

7 0 1 Yellowish green

9 0 1 Yellow

11 0 1 Yellow

DISCUSSION

In this experiment, the same type of species of Lemna sp is used so that the the results are more

reliable. The Lemna spp are taken from the same area or habitat so that the rate of growth is

the same for all plants. Besides that, it has to be taken from the same species because different

species has different rate of growth. One limitation that we cannot avoid at all is the level of

maturity of the Lemna sp. Some of the Lemna sp are young and some of the Lemna sp are old. In

order to minimize this limitation, we should choose the Lemna sp with almost the same size,

though the size of Lemna sp does not indicate the maturity of the plants. Each petri dish

contains 5 Lemna sp and this amount of Lemna in each Petri dish should be constant for other

Petri dish. This step is vital to ensure the nutrients are divided equally to 5 Lemna spp and avoid

any further competition.

Secondly, all the Lemna sp must be carefully extract and place gently and carefully into the

cultured nutrients solutions. The solutions are freshly made so that the data obtain is valid and

reliable. Before the solutions are poured into the Petri dish, the Petri dishes must be in sterile

condition in which there is no contamination by the foreign substances. If the petri dishes are

polluted, there will be a competition occurs between Lemna sp and the pathogens, resulting in

inaccuracy of data.

Next, the observation of the Lemna sp is recorded in every two days, making six observations

overall. The observation of the Lemna sp is taken from several aspects which are number of

roots, number of leaves and colour of leaves. It is a bit difficult to record the observation

because the size of Lemna is very small. However, according to the above table, it states that

there is no changes in the number of roots and number of leaves. This indicates that the plants

have died from the very first day. There are several unavoidable errors and limitations that

cause the plants to die. The first reason is due to the contamination of the Petri dishes which

causes the plants to be infected or maybe because there are strong competitions exist between

Lemna sp and the microorganism. The competitions occur in the aspect of receiving sunlight and

nutrients. The second reason is because the Lemna spp have already died before being

transferred into the Petri dishes. When we are transferring the Lemna sp using the forceps, we

might be putting excess force on the forceps and this causes the Lemna sp to be crushed and

died. The last reason is the major cause of this failure results in which the Petri dishes are left

opened for a night and this causes all the nutrients to evaporate and the Petri dishes are dried.

The Lemna spp are left dried in several hours until the condition become very unfavourable for

them to live. The unfavourable conditions for this type of plant are dry and deficient of nutrient.

Another observation that are taken into account is the colour of the leaves. The colour of the

leaves for all the plants shows the same changes; from green to pale yellow and then to yellow.

This shows that the plants are died and they are not died because of the deficient of nutrients. If

they die due to nutrients deficiency, the observation should be different. For example, the

leaves should be white in colour instead in yellow colour for Lemna sp in lacking calcium

solution. These reasons also explain why the Lemna sp does not grow any roots and leaves. It

means the Lemna sp has died from the first day of experiment due to human mistakes and

unavoidable limitations. From overall perspective, the results of this experiment is not valid and

unreliable at all due to the reasons that I have stated above.

EVALUATION

Errors and Improvements

The errors that are aroused during the experimental process can lead to inaccuracy of the result.

The first source of error is when the Petri dishes containing the nutrients solution are exposed to

the surrounding air and atmosphere during the preparation of Lemna spp. in which Lemna spp.

had to be transferred into the Petri dishes. To put it in other words, they are not covered with

lids. This can cause the entry of microorganisms or foreign substances or maybe pathogens as

the cultured nutrient solutions might become a favourite condition for the bacteria to grow.

Nutrients evaporate and dry if the Petri dishes are left open for a day and this can cause Lemna

spp. to die as they are aquatic plant and they cannot live in dry condition and without nutrients.

This can be overcome by closing the Petri dishes as soon as possible to minimize the entry of

foreign substances that can disrupt the growth of the Lemna spp..

Besides that, during choosing the Lemna spp., the chosen Lemna spp. can be mature and can be

immature as they are randomly picked by human. Also, the chosen Lemna might not be in a

healthy state and some of them probably had undergone the effects of nutrients deficiency

without being noticed by us. This can be solved by picking the Lemna spp. with almost the

similar physical appearance. For instance, choosing green-coloured leaves instead of yellow or

pale green. The yellow Lemna sp. might have undergone chlorosis. Also, choosing the same size

of Lemna spp. for the same Petri dishes. Apart from that, the Lemna spp. might already be

crashed by the forceps during the choosing of the plant. This can cause Lemna spp. died straight

away before we can investigate the effects of plant minerals deficiency.

Moreover, the process in which transporting the Lemna spp. from the laboratory to the

classroom causes several problems arise. The nutrient solutions are spilled and this causes the

volume of the Petri dishes are not even. Some of the Lemna spp. is not fully immersed in the

culture solutions as some of them stick to the cover of the Petri dishes whereby the solutions

cannot be reached. Therefore, the nutrients intakes by the plants are not the same. This

problem can be overcome by covering the Petri dishes with cling films and bring them slowly

and gently to the class without spilling the nutrients.

Limitations

There are a few limitations in the experiment which has to be taken into account and can affect

the results of this experiment. One of the limitations of the experiment is the experiment is

conducted in an exposed air. This apparatus are contaminated with various foreign substances

as we respired and talked while conducting the experiment. This can cause other bacteria get

into the Petri dishes that contain the cultured nutrient solution and this solutions might be a

favorable condition for the bacteria’s growth, thus, raising competition between the impurities

and Lemna spp. This can disrupt the growth of the Lemna spp.. This can be minimize by cleaning

the Petri dishes with tissue paper and cover the Petri dishes with lid to prevent the cultured

solution being exposed to the surrounding environment.

Besides that, many limitations are faces due to the Lemna spp. These plants have many species

and they are varying in size and features. The size of Lemna spp. are too small and they are

difficult to be detected any changes or observed. Due to the size, there are too many error

occurs during the observation. Moreover, each Lemna sp. has different level of maturity. So,

some of them can be too matured and old while some of them are too young and immature.

They will, therefore, grow at different rate.

Furthermore, the weather of surroundings cannot be controlled. If the weather is too hot or too

cold, it is not a suitable environment for the growth of Lemna sp. The hot weather can cause the

cultured nutrient solution to dry quickly while the cold weather can disturb the growth of the

Lemna sp.. This can be overcome by placing the Petri dish containing the Lemna sp. in a

classroom as the classroom is not too warm or not too cold. The Petri dishes are placed near the

windows so that the plants can obtain maximum amount of sunlight for them to carry out the

photosynthesis process.

Last but not least, the Lemna spp. might be grown in deficient nutrients environment and the

Lemna sp. might already have the effects of nutrients sufficient. So, the results are in accurate.

This matter can be overcome by choosing the healthy Lemna spp. and avoid choosing Lemna

spp. that has palpable deficient nutrient symptoms such as chlorosis, red or purple spots on the

leaves or brown spots appear on terminal leaves.

Safety Precautions

Throughout the experiments, there is safety precautions that are taken to avoid the conditions

that might lead to the inaccuracy or invalidity of the results obtained. First and foremost, the

basic and simplest safety precautions that are needed to be followed by all students are wearing

lab coat and a pair of suitable shoes are compulsory when conducting an experiment in the lab

at all times to protect the skin and clothes from chemicals such as the cultured nutrients

solutions. The cultured nutrients solutions might be a favourable condition for the growth of

foreign substances. This can be overcome by handling the solutions using gloves and face masks

as well as lab coat and eye protection.

Furthermore, the glassware such as measuring cylinder and beaker should be handled with full

care because they are fragile. Avoid consuming any solution that used in this experiment

because they might be contaminated. In addition, the hands whose conduct this experiment

need to be wash cleanly after handling the nutrients solutions to avoid any contamination that

can bring harm to your health. Also, be careful when using forceps, while extracting the Lemna

sp from the beaker to move them into Petri dishes, as it can harm other people. In addition,

there would be a risk that the volume of cultured nutrients solution in each of the Petri dish

might not be constant. This occurs due to the parallax error when reading the scale on the

measuring cylinder. The eyes of observant must be perpendicular to the measuring cylinder and

the reading is repeated with other students to ensure the precision of the results. It is

indispensable to avoid any inconsistency of the volume of the solution in each Petri dish as the

results will not be valid to the test of the deficiency of the plant mineral in the Lemna sp.

Students should take note as well to behave themselves while in the laboratory by not running,

eating, drinking or joking around while conducting the experiment. It is compulsory to wash all

the apparatus under running tap water after using them and return to their original places.

CONCLUSION

The Lemna sp in complete nutrients solution has the highest number of plantlets and they grow

healthily. Other than that, we can say that all the macronutrients and micronutrients are very

significant in sustaining the growth of the Lemna and the deficient of each nutrient will affect

the Lemna sp in many ways. The hypothesis is accepted.

REFERENCE

1. http://soils.wisc.edu/facstaff/barak/soilscience326/macronut.htm

2. http://www.ncagr.gov/cyber/kidswrld/plant/nutrient.htm

3. http://www.eldoradochemical.com/fertiliz1.htm

4. http://landresources.montana.edu/NM/Modules/Module9.pdf

5. http://5e.plantphys.net/article.php?id=289