Soil Compaction

[jameso7]

You can hide this advertisement by registering.

I have an assessment on soil compaction next week, does anyone have a good prac and method to do to measure this?

[Cat_Orange]

Not entirely sure if my info will help - we did compaction a couple of weeks ago and our pracs were a little dodgy to say the least.

1. One was growing seeds in compacted and noncompacted soil
2. One was measuring porosity, filtering water through compacted and noncompacted soil to see what would happen
3. One was building up mounds of compacted/noncompacted soil and tipping water over them.

Probably the best to prove compacted soil is bad is the 2nd one, less water goes through and you can link it back to evaporation and salinity. Although the third one does sort of prove that compacted soil causes erosion.

Uhh.. hope that helped in some small way. If you don't get it... well, I don't blame you.

[goodrobo]

cat orange is the stuff wen it comes to ees!
I jus did an assessment on this very same junk - im sure compaction will save my life some day when im climbing cliffs and need the skills to stay alive.
Anyhoo, 35/40.. heres wat i got.


Aim:
To test how the amount of soil compaction of a soil sample affects the ability of water to infiltrate soil and the germination rates of radish seeds in the soil.

Hypothesis:
I believe that water infiltration will be affected by how compacted the soil is- how tightly packed the soil particles are. The tighter the soil is compacted, the less movement there will be of water.
Also, I believe the compaction of soil will affect the germination rates of radish seeds in the experiment. Because one of the samples of soil will be very tightly compacted, water will not be able to get to the seeds in time and if it grows, will not be able to sprout.

Safety:
No human contact must be made with the soil samples at all times during the experiment.
Must be kept outside in the sun to attempt to germinate seeds, making sure it is out of reach of human or animal contact. Finally, approach the experiment with caution, as not to disrupt the water pattern or growth of seeds in the soil samples. If handling is necessary, gloves may be used as to not disrupt the growing process. With the safety followed and completed, the experiment will be accurate and follow the hypothetsis.

Equipment:
- 2x Plastic see-through containers to hold the soil
- 2x 200mL rations of Water for each container
- Fertile Soil
- Small packet of radish seeds
- Sunny, safe environment to grow seeds in.

Method:

• Select fertile soil from the same chosen location, make sure that both samples are the same type of soil and are the same type of soil (colour, particle size etc.)
• Gather materials & equipment as stated above.
• Place radish seeds 6mm underneath top of soil. Make sure both containers are identical, except for soil compaction (One container compacted the other loose as a control)
• Pour 200mL of water to each container, time and monitor the infiltration rate of the water using a stopwatch. Time how long it takes for the water to sink to the bottom (or as long as it descends before it stops – this will apply most likely to apply to the compacted soil sample).
• Monitor each day for seven days for seed growth in comparison to the soil compaction for each container and record in a table.

Results:
Progress
Day 1














Day 2


Day 3







Day 4







Day 5







Day 6





Day 7


Description
Seeds planted to correct depth. Correct water amount added. I noticed that it was extremely hard for the water to infiltrate the soil that was heavily compacted. For around 30 seconds the water was floating, sitting on the top of the soil, unable to seep down to the bottom, or even the seeds 6mm under.
It took around 10-15seconds for the water to seep to the bottom of the looser, less compacted soil. The water sank so fast because the soil particles were not pushed tightly together, creating an easy passageway to the base of the container.

Condensation buildup overnight on both containers; some seeds exposed.

All seeds, even the exposed ones, have begun to sprout. The seeds show trouble penetrating the surface of the compacted sample, with only around 5 of the allocated 40 seeds sprouting to the surface.
Every seed in the less compacted sample has begun to sprout. 40/40

The seed sprout’s roots in the non-compacted soil sample have turned purple and green, and are digging into the soil.
The compacted soil’s sprouts have turned purple, but have not gone green on the top, indicating a slower germination rate.


Enormous growth in 24 hours on both sides. Green leaves and buds have formed in both samples, but are less developed in the compacted sample. There seems to be much less spread of growth and roots in the compacted soil, it must be hard for the roots to dig deep.

Sprouts have started growing upwards, creating green stems. I’ve also noticed that the soil in both containers has become lighter, perhaps leeched of its nutrients.


On the final day, real comparisons could be made between the two samples. Per square centimeter, more seeds germinated and grew in the non-compacted sample. A total of 33 buds grew to full in the non-compacted soil compared to 10 buds in the compacted sample.
Both samples growth speed were relatively equal, however the non-compacted was faster by about half a day’s growth.

One of the most important comparisons were the roots that grew inside the containers. The amounts of roots visible were far apart for each of the samples. The roots covered the non-compacted soil all around the container to the bottom.
The compacted soil’s roots obviously had trouble growing through the soil as only one major root could be seen at the bottom of the container.



(Criteria said include a graph so just make up some stuff on excel i still got full marks for it)

Conclusion:
In conclusion, the stated hypothesis was correct, with the non-compacted soil acting faster in the germination rates of the radish seeds selected. Both sample’s seeds germinated but the non-compacted soil was faster. However, soil compaction has been known to improve the germination rates of seeds because they bring the soil particles in reaction with the seeds and roots easier, but if too heavily compacted, will result in restricted growth.

[goodrobo]

Oh upon looking the results werent even there


Day 1:
Description
Seeds planted to correct depth. Correct water amount added. I noticed that it was extremely hard for the water to infiltrate the soil that was heavily compacted. For around 30 seconds the water was floating, sitting on the top of the soil, unable to seep down to the bottom, or even the seeds 6mm under.
It took around 10-15seconds for the water to seep to the bottom of the looser, less compacted soil. The water sank so fast because the soil particles were not pushed tightly together, creating an easy passageway to the base of the container.

Day 2:
Condensation buildup overnight on both containers; some seeds exposed.

Day 3:
All seeds, even the exposed ones, have begun to sprout. The seeds show trouble penetrating the surface of the compacted sample, with only around 5 of the allocated 40 seeds sprouting to the surface.
Every seed in the less compacted sample has begun to sprout. 40/40

Day 4:
The seed sprout’s roots in the non-compacted soil sample have turned purple and green, and are digging into the soil.
The compacted soil’s sprouts have turned purple, but have not gone green on the top, indicating a slower germination rate

Day 5:
Enormous growth in 24 hours on both sides. Green leaves and buds have formed in both samples, but are less developed in the compacted sample. There seems to be much less spread of growth and roots in the compacted soil, it must be hard for the roots to dig deep.

Day 6:
Sprouts have started growing upwards, creating green stems. I’ve also noticed that the soil in both containers has become lighter, perhaps leeched of its nutrients.
Day 7:
On the final day, real comparisons could be made between the two samples. Per square centimeter, more seeds germinated and grew in the non-compacted sample. A total of 33 buds grew to full in the non-compacted soil compared to 10 buds in the compacted sample.
Both samples growth speed were relatively equal, however the non-compacted was faster by about half a day’s growth.

One of the most important comparisons were the roots that grew inside the containers. The amounts of roots visible were far apart for each of the samples. The roots covered the non-compacted soil all around the container to the bottom.
The compacted soil’s roots obviously had trouble growing through the soil as only one major root could be seen at the bottom of the container.



====== Heh dont you love it when ppl put assignments on BoS? =======