Info
| Explore |
Work on this next! What do we know about plants from our experiences outside of school? What have we discovered in class and background research? What questions about plants interest us? |
|---|---|
| Research Question | What do we want to test or study? How did we come up with the question(s). How does the question fit what we know about the topic? |
| Predictions | What are the possible outcomes of our study given the variables we are working with? What is our explanation for why and how we think this will happen? |
| Experimental Design | What is our plan? Be sure to include enough detail that another group can replicate our experiment. What variables will we test? What variables will we measure and observe? What variables will we keep constant? How will we record our data? |
| Conclusion | What claim can we make from our experiment? What are possible explanations for our results? How do the data we collected and our reasoning with scientific ideas support our claim? What future experiments could be done to expand on the results of this experiment? |
| About this Project |
Despite finding issues with their seeds germinating this team kept on trying and communicating with their mentor.They addressed issues of watering and found in the end that [the treatment that] did not have fertilizer grew. They began to suspect that the fertilizer had something to do with... |
Updates
As this research project is now in the final stages of wrapping-up, we wish to thank everyone who participated in this inquiry; the students, mentors, teachers and others behind the scenes. We appreciate all of your efforts and contributions to this online learning community.
Scientific exploration is a process of discovery that can be fun! There are many unanswered questions about plants just waiting for new scientists to consider, investigate, and share.
After the end of the session, we will be updating the platform and archiving groups and projects, after which time new updates/posts will not be able to be added to projects or groups. Please come back and visit the PlantingScience Project Gallery anytime to view this project in the future. You can search the Gallery by keyword, team name, topic, or school name.
Good bye for now.
Warm regards,
The PlantingScience team
It’s great to see that teams from your school are wrapping up and posting conclusions. Enjoy the final stages of your project, and feel free to post any final comments or questions you have for your mentors.
So, it looks like the fertilizer was toxic, even at 11 drops! Even if this wasn't the result you're expecting, it's actually a very informative experiment. I haven't observed fertilizer toxicity that stops seed germination yet - so this was actually a novel result for me! I had to actually look up how fertilizer can cause seed death as it wasn't something I had not really heard of before. Typically, putting too much fertilizer on plants causes what farmers call "burn". It's called burn because the plant will develop yellow and dry spots, which can also happen if the plants are overheated. These spots are where the plant has dried out, and they dry out because of the high salt levels in fertilizer (the nitrogen, phosphorus and potassium are typically added to fertilizers as salts). Often the worst ions for this are urea and ammonium nitrate salts, which are added to give the fertilizer nitrogen. The high salt concentration will often kill the seed/prevent it from germinating. Do all you have any ideas how high salts would kill the seed/germinating plant?
Also, what might be useful in drawing a conclusion is to actually dig out the seeds that didn't grow. It could be interesting to see if they germinated at all (where you see a small plant emerging from the seed that then died) or if there was absolutely no germination. Considering Ragene said there was a bit of green that poked out of the 11 drop soil last week, I think you might see a difference between the seeds you dig out.
We are reaching the end of the experiment. Only the non-fertilizer plant continued to grow. Could you tell us why the excess amount of fertilizer negatively affected the plants?
This is interesting! I'm curious to see if there is anymore growth in the 11 drop pot - but it does look like you're getting some interesting results!
As to whether 11 drops was too much: this is very dependent on how concentrated your fertilizer is. For reference, I use a solid fertilizer that you use by dissolving it into water when I'm growing plants, and I typically dissolve 4g of the fertilizer into 2 gallons of water, which waters between 60 pots (the 4g/2Gal is the recommended concentration listed on the container). So, the amount of fertilizer to use can be really very low! It's hard to say whether 11 drops is definitely too much without a concentration, but it does sound like it could be negatively impacting growth.
The same pattern continued. Only the pot without fertilizer grew. The individual size of the pot is similar to an ice cream cone. We put in 11 drops in one and 33 drops in the other, expecting only the 33 drop to harm the growth. I saw a little bit of green poking out from the 11 drop soil a few days ago, but as the soil shifts, it was buried again.
It's been great to get the updates on the plants! Have you all seen any more growth since Wednesday? You've all mentioned that you think that the fertilizer could be negatively impacting growth, and I can actually think of some reasons why that happened - but I'm curious as to whether any of you have any ideas about what in fertilizer could negatively affect growth.
Also, I'm curious as to what size pot you're using - this could be making the fertilizer amount you added more or less concentrated in the soil, which could affect the seedling growth. This might be useful in terms of figuring out what's going on with these results!
When we checked our plants today, a new plant sprouted in the other well with no fertilizer. As of now, only the plants in the section with no fertilizer are growing.
Only the seeds in the non fertilizer pot have grown. Also, when watering the pot, the fertilized pots seem to absorb water much quicker than the non fertilizer pot. I think we need to examine the fertilizer to make sure there were no errors.
Today in the lab we only observed the change in the non fertilized pot. The other two remained the same.
Is it possible that adding too much fertilizer may affect or actually cause damage to the seeds?
We only see the growth from non fertilizer pot. We did not see any change from the other pots. We added the water the way you shows us before(bottom watering).
When we checked on our plants today there was more growth in one of the wells with no fertilizer, and in that section there are two plants that have sprouted. Other than those two, there has been no growth in any of the other wells in the container.
It could be that the seeds are a little slow to sprout - just make sure all of your pots are well waterered. It could also be that the fertilizer is affecting the sprouting - difficult to tell at this point!
Surprisingly, the one without fertilizer starts to grow, but we did not see any changes from other two pods. This is opposite from what we expected. We thought plant with fertilizer will grow more. What could it be the reason for that? I personally think the fertilizer gets poison for plant somehow.
It's possible the fertilizer has affected the plants, but it's less common for the fertilizer to affect germination of seeds.
Today when we checked our plants only one of the radish seeds had grown and it was in the cup with no fertilizer. No other seeds have sprouted since we last checked them on Friday.
This is a good way to cover your pots to help keep the soil moist.
If the top of the soil is dry after 2 days, I'd really make sure to get the soil well watered without really worrying about over watering it. Usually I find that my soil doesn't dry out as quickly, but so many factors (type of soil, temperature, humidity, pot size) can affect this that it can be hard to predict how frequently you'll need to water. I have actually seen seeds germinate in water, so I wouldn't worry too much about over watering the soil! It's really more of an issue with plant growth long term. Another thing you can try to keep the soil most is to loosely put a covering of cling film over the pots (make sure it is loose - don't seal the pots tightly!). This reduces water evaporation from the soil surface. I usually put a plastic lids over my pots when I'm trying to germinate seeds. Just make sure to remove the covering once you see the plant emerge from the seed.
It has been three days since planting the seeds, and we do not see anything so far. Looking back, we have not accurately measured the depth of which the seeds are planted. I hope the depth is adequate for the seeds to sprout. The soil was dry before we watered them. The top soil was dry, but there are relatively large stones which may explain the dry soil.
There is no change in the plants, and we added some water today.
Hi all - I've seen a few posts asking about how much to water plants. This is a really great question, and is actually a pretty tricky part of growing plants - in my time growing plants in the lab, I have definitely over- and under- watered my plants, and have learnt a lot about what the correct amount of soil moisture looks like from experience. My best tip from years of growing plants is to use the bottom watering method, where water is added to the dish you put the pots in, this is left for about 10 minutes, and then the excess water is discarded. I've put a diagram in the "Files" section of this page, and would recommend you have a quick look at that. I find that if you're bottom watering the plant, the soil ends up at nearly the perfect moisture level every time! Let me know if you have issues finding the diagram. Also, feel free to add pictures of the soil to the Files section, and I can try and see if it looks too moist/too dry. I don't think that fertilizer being washed out will be too big of an issue given this is a short running experiment (if you were going to grow the plants for over a month, then I'd suggest more fertilizer). Bottom watering will also help avoid fertilizer runoff.
Got it！ Thank you so much!
We added same amount of water into the pots today. There is no changes for all six pots.
We put seeds into 6 different pots and added water on the first day and the second day. We set up 2 pots for no fertilizer, 2 pots for a regular amount of fertilizer, and the last 2 for more fertilizer. We did not observe any changes in the plants so far. Is it necessary to add water every day? I was worried that too much water might damage the seeds. Also, because we are using liquid fertilizer, we are wondering if the effect of the fertilizer might change if we keep adding water to the soil.
Long explanation: watering everyday probably isn't necessary, but how frequently you'll need to water depends on how dry/hot the place you're growing the plants is. Soil for seed germination needs to remain moist, otherwise the seeds won't germinate. However, too much water can be bad as well. General advice is you want moist soil - this usually looks dark brown, but will leave some water on your hands if you squish the soil between your fingers (like a small film of water, not like squishing a wet sponge). Overly wet soil might have pools of water, or feel muddy. Soil that is too dry becomes light brown, and it is way too dry if it gets crunchy/crispy. I'm sorry this is such a long explanation on identifying soil - it's really hard to describe the ideal wetness that the soil should have - the best way to identify it is by feeling the soil.
My advice for the easiest way to keep your plants well watered without over watering is to use a method known as bottom watering. I've put a diagram on how to bottom water plants in the Files section of this page (see the panel on the left). Bottom watering prevents over watering (the soil will only take up as much water as it needs from the dish, as long as you discard the water in the dish after 10-20 mins). It will also be less likely to wash out fertilizer from your pots (if you add too much water to the soil, it eventually flows out of the bottom of the pot and can carry nutrients with it). I would probably not worry too much about fertilizer run off, as this is a short experiment - I would worry more if this was a month long growth experiment. I find in the lab one fertilizer application is enough for seedlings.
Short summary: Watering everyday is probably too frequent, every 2-3 days should be enough, but I can't know for sure as I haven't seen the soil. Bottom watering is the best method to get the correct amount of water into the soil, and will prevent fertilizer from washing out. There's a diagram of how to bottom water in the Files section of this page (in left hand column)
We put the seeds into the pot. Since we have 6 different pots, we did the lab twice. I think that will lead us to have more credible results. This morning, we checked the plants. I could not see any changes. I am just wondering the differences between liquid and solid fertilizer. Also, how often we should put wanter in it. If we put too much water, the fertilizer will be weaker. However, if we don't put water, I think the plant won't be able to grow.
That's great you could do two pots per treatment! Good question about watering plants! This is true, watering can rinse out fertilizer, to an extent, but it shouldn't be an issue. Generally, when you're germinating seeds, you want moist soil, but not wet. Seeds need to take up water to germinate properly, so if it gets too dry, you might run into an issue. The best way to avoid over-watering is to water the plants from the bottom of the pot - so, if your pots are sitting in a tray/dish , add water to the bottom of the dish, and wait about 10 mins for the soil to take up the water. Then, pour the remaining water out of the tray/dish. Make sure to check up on the plants frequently to make sure the soil is still moist - how often you have to water depends on the size of your pots/humidity/temperature/type and age of the plant you're watering.
Solid v. liquid fertilizer:
Solid granules - these you mix into soil, not water. They sit in the soil and release nutrients over time. You don't need to reapply as much, and the amount of nutrients the plants can take up is affected as the nutrients aren't evenly distributed through soil as other types.
Liquid fertilizer (and solids that you dissolve into water to form a liquid that you add to plants): These add a more even blend of nutrients throughout the soil. They typically need to be reapplied more often as they don't sit in the soil slowly releasing nutrients, like granules do.
I wouldn't worry about reapplying over the course of your experiment even though you've used liquid - one application is enough for seedlings.
Also: typically I water my plants when the soil is starting to dry out. Given that these are seeds you're trying to germinate, you'll want to be sure the soil is moist, so I would guess you'll need to add some water every 2-3 days. However, this is very location dependent! If they are looking dry, water more frequently, if they are looking overly moist (a sign of this is green algae or white fluffy fungus on the top of the soil), cut back on the water. Just make sure the pots aren't sitting in trays/dishes with water - that should be drained off after each watering.
Short summary of watering as I know that was kind of a long answer:
1) Keep the soil moist and don't let it dry out - I wouldn't worry about the water washing out the fertilizer in this experiment.
2) Make sure there isn't water sitting in the tray/dish the pots are in - that's typically how they end up over-watered.
I've replied to a few specific questions on the comments. Some general comments - a number of you have stated that you think the fertilizer will affect growth. How do you think it will affect growth? Why do you think that the growth will be affected by the fertilizer?
Also, with fertilizers, they typically have a variety of nutrients necessary for plant growth. However, all fertilizers have compounds that have the elements nitrogen (N), phosphorus (in phosphate) (P) and potassium (K). Fertilizers will have these in different ratios, which is known as the NPK number, and most fertilizers, even if they don't list ingredients, will have the NPK number displayed on them - for example, this fertilizer https://www.flinnsci.com/fertilizer-all-purpose-liquid-32-oz/fb0676/ has an NPK number of 10-15-10. This means that by weight, 10% of the fertilizer is N, 15% is P (in the form of P2O5), and 10% is K (in the form of K2O). The remaining 65% is inert ingredients/other minerals. If you can find the NPK number, great! If not, no problem! The most important nutrients to think about when thinking about your experiment will be nitrogen, phosphorus, and potassium, so even if we don't know the exact ingredients, we can think about how those three could affect the plants.
It would also be great to take photos of the plants in addition to weighing them - I suspect photos will help interpret the results.
Just out of interest, where are you growing your plants?
I look forward to hearing about the results!
We have prepared the pots and are waiting for the seeds to sprout. It took three days for the seeds to sprout for the previous experiment, so we don't expect to see anything this week. We gave 10mL of water for each pot. We could not determine the chemical composition of the fertilizer since it does not have information on the label, and the fertilizer is from Flinn, and is not commercially sold. The soil we used seem to have large grains of dirt, it may be a chunk of dry dirt, or a stone. We hope the masses do not interfere with the sprouts. We will be back on the experiment Friday.
Usually the plants do pretty well even if there are chucks in the soil - I often find small twigs in the soil we use in the lab and it doesn't seem to affect their growth.
Yesterday, we finished setting up our experiment and put the appropriate amount of fertilizer in each sample. Once the experiment was completely set up, we added about 10mL of water to each well, and placed it under the artificial light in our classroom. We checked on our plants today in class, but we will not be back in this class until Friday, so we will not be able to monitor the plants Thursday.
The lab we were planning has started yesterday, and we are preparing our pots and starting our seeds. We have decided to use the liquid fertilizer, and three tests: no fertilizer, 1g fertilizer, and 3g fertilizer. We have two pots per test, and three seeds per pot.
Today in class we started our experiment with the fertilizer. We split the container that was given to us into three different sections, and each section has two spots for our plants. We are testing whether or not the amount of fertilizer that is give to a plant will impact how quickly the plants will grown. In the first section, the seeds will not have any fertilizer given to them. The second section will only be given 1.1g of fertilizer, and the third section will be given 3.3 g of fertilizer. We only added fertilizer to the second section, but we will finish everything else tomorrow.
Due to the power down and long weekend, our final lab delay, but we finally started it today. We use liquid fertilizer. Unfortunately, I could not find information of component of fertilizer. We decided to put three seeds into each pot. We will put all of the pots under the light and keep giving save amount of water. We will only change the amount of the fertilizer. I think amount of fertilizer will effect the growth speed of the plant and strength of plant.
We started the fertilizer experiment in class and what we are looking for is how does the amount of fertilizer can affect the growth of plants. We set up 3 containers that have different amounts of fertilizer, so we can compare the outcomes. We are using liquid fertilizer for this experiment. For container 1 we are going to put no fertilizer in it, we put a regular amount(about 11 drops?) amount of fertilizer in the container 2, and for container 3 we are going to triple the amount of fertilizer in container 2 and put it into the soil.
Instead of the fertilizer lab, we started a different lab by using radish seeds in order to figure out how plants gain mass. In order to find out, we created three cases. Dish one has seeds with water and lights, dish two has seeds with water, and dish three has seeds with light.
Data:
#1
Dish - 3.32g
Dish w/ seeds - 3.67g (seeds - 0.35g)
#2
Dish - 3.32g
Dish w/ seeds - 3.67g (seeds - 0.38g)
#3
Dish - 3.32g
Dish w/ seeds - 3.85g (seeds - 0.53g)
Also, once you get more of your experiment planned for the fertilizer experiment, if you post it here, I can give you all feedback on it before starting the experiment. It sounds like it should be an interesting experiment!
The radish experiment sounds interesting - I'll be interested to hear what results you get!
In the new lab there we are doing right now in class, we need to find out where do plants gain their mass, the possible answers now included nutrients that plants absorb, the growth of plant cells, or the amount of water they absorbed. We used radish seeds and put them into different environments in order to observe what variable might affect the mass of the seeds.
We create 3 different conditions:
Dish #1 with lights and water
Dish#2 with only water
Dish #3 with only lights
Data:
Dish #1(water and light)
Dish: 3.32g
Dish with seeds: 3.67g
Seeds: 0.35g
Dish #2(only water)
Dish: 3.32g
Dish with seeds: 3.70g
Seeds: 0.38g
Dish #3(only light)
Dish: 3.32g
Dish with seeds: 3.85g
Seeds: 0.53g
Other than the lab we were talking about, we started new lab by using radish seeds in order to figure out where plants get their mass. We created three different conditions. Dish one is seeds with water and lights, dish two is seeds with water, and dish three is seeds with light. We put all of the dishes into the ziplocks and close them.
#1
Dish 3.32g
Dish +seeds 3.67g
Seeds 0.34g
Dish +seeds+water 3.34
#2
Dish 3.32g
Dish+seeds 3.70g
seeds 0.38g
Dish +seeds+water 3.38
#3
Dish 3.32g
Dish+seeds 3.85g
seeds 0.53g
In the new lab we are doing in class, we are testing how the growth of radish seeds is impacted by its environment. We are testing this by changing the conditions in which we put the samples of radish seeds, and measuring their growth over a two week period. Today, we sectioned off the seeds into three dishes, measured the amount of seeds, and placed them into their designated conditions. The first sample will have water and be placed under a light source, and the other two will only be exposed to either light or water.
Sample Measurements:
Sample #1 (Light and water):
-
Container Mass: 3.32g
-
Container mass with seeds: 3.67g
-
Seed mass: 0.35g
-
Sample #2 (No light and water):
-
Container Mass: 3.32g
-
Container mass with seeds: 3.70g
-
Seed mass: 0.38g
-
Sample #3 (Light and no water):
-
Container Mass: 3.32g
-
Container mass with seeds: 3.85g
-
Seed mass: 0.53g
-
One other thing - think about how many plants per pot, and how many pots per fertilizer amount you want to look at for the fertilizer experiment. Multiple replicates are important for good data! I'm not sure how big the pots are that you're planning to use - generally I'd say no more than 2-3 seeds per pot is a good starting point.
Analysis:
After 24 hours of being submerged under breath and baking soda cup, eight disks from the baking soda floated to the surface of the water while the disks from the breath cup remained the same. After 48 hours, all of the disks floating sank. This somewhat supports our hypothesis since it is evident that photosynthesis took place in the baking soda cup.
Conclusion:
The leaf disks floated to the surface of the cup by absorbing CO2 from the solution. The disks then fell because it no longer was capable to photosynthesize. Possible source of error is the lack of observation. There were no observed floating disk from the breath cup. However, it is reasonable to think that it rose and fell during the night. A camera programmed to take a picture at a given interval could solve the problem.
I think that's a good point that because you weren't observing the cups at all times, it's possible you could have missed the leaves in the breath cup floating.The camera idea is great! I've done that for experiments that need to go on overnight in the lab so that I can see what happened when I wasn't there. However, the leaves in the baking soda cup appear to have floated more (enough that you could observe it) - why do you think they floated more?
Also, you've said that leaves float to the surface of the cup by absorbing CO2 from the solution. You've also mentioned that photosynthesis is important for floating. What do you think about what happens during photosynthesis that allows the plant to float?
50 mL beaker
fertilizer (liquid)
pipet
soil
lighting
water
electric scale
container
seeds
This looks like a pretty complete ingredients list for the experiment Saki has suggested about studying how fertilizer affects growth. Do you know which fertilizer you plan to use?
For next lab, I want to test how the fertilizer can affect the plant growth.
We can create three different amount of fertilize with solids, and observe any relationship between amount of fertilize and growth.
I want to know putting tons of fertilize can actually grow plant more than plant with less fertilize.
That is an interesting question to test! I have a few questions/points you might want to think about as you plan the lab.
1. What amounts of fertilizer would you try, and which fertilizer would you use? Using too much for all three amounts, or too little might mean it is difficult to see differences between the amounts.
2. What would your control be?
3. What other variables could affect plant growth, and how will you control them?
4. How are you going to measure plant growth? There are many different ways to do this, with the most common being height or weight.
5. Fertilizers usually have a few different elements in them that affect plant growth in different ways - the standard key elements in a fertilizer are nitrogen, phosphorus and potassium, as they are important for plant growth. Some might have other minerals that plants use as well. How might the different elements impact plant growth as you use more fertilizer?
Also, based on the data, we can know that photosynthesis will take time to create enough oxygen to flow the leaf discs up. If we can measure the amount of oxygen and carbon dioxide occurred every hour during this lab, we could be able to find the speed of photosynthesis. By figuring out of this, we can know the reason for those discs which float once but sank. It can be because leaf discs are not healthy for day 3, or leaf discs used every CO2 in the solution so that leaf discs cannot photosynthesis.
I think that you're probably right in that either the CO2 is used up or the leaves aren't healthy enough on day 3 to photosynthesize and float. Trying to measure the rate of photosynthesis would be a great way to test this! Could you think of a method that could be used to measure the concentration of CO2 in the water, or the O2 that is released?