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Appréciation
Concernant la présentation orale.
La durée est "presque" parfaite (4:30 mins)
Attention Ă la prononciation de certains mots comme "put", "know", "while", "composed", "fine", "thick", "compare", "finally"
Il y a quelques erreurs comme "We're going to talk you about of the subject" =} "We're going to talk to you about the subject ", "experiences" =} "experiments, "the problematic" =} "the problem-question, "what are the impact or….. is the impact of citrus fruit on compost?", "For make To do the experiment…", "we have make 6 many compost forms have made 6 different forms of compost, witness compost =} a control sample, more faster =} faster
N'oublie pas de bien prononcer le morphème –ed :
Certains mots sont mal prononcĂ©s dans cette phrase "We know what???????? in the compost as well.???? one…??? citrus"
Attention Ă la place des adjectifs - il faut les mettre devant les noms : "Citrus thick-skinned" =} thick-skinned citrus fruit, "mass original" =} original mass
Il faut bien prononcer les "s" à la 3ème personne du singulier et après chaque mot au pluriel.
N'oublie pas de bien prononcer le morphème –ed : "…we divided the classe into…"
C'est assez présenté et ton texte est convenable.
Compost
History of composting
Long before people inhabited the planet, composting was just something that happened. In every swamp, forest and meadow , wherever there was vegetation ,there was composting. Then, sometime in the distant past one of our ancestors noticed that crops grew better near piles of rotting manure and vegetation.
The discovery was passed down to succeeding generations. Composting, that perfectly natural process that just happens, became something our ancestors learned to use.
Now, organic methods in gardening and farming are becoming increasingly popular. Even farmers who rely on expensive fertilisers recognise compost's value for plant growth and restoring depleted and lifeless soil. The research into organic gardening and composting is still being carried on today by such organisations as The Henry Doubleday Research Association.
The subject/observation/ problematic
The subject
For search the subject we haven’t need to make a brainstorming,we are directly passed at compost. My fath is passioned of gardening and owns himself own compost , he gave us documents and information about it. In a compost we must not put meat, fish and don’t put flowers with diseases. But we not know if can put citrus in the compost.
Observation
We've been doing research on compost. The reasons for composting are:
• Natural fertilizer
• Reduce weight
• Limit waste
• Waste less
The reasons to do compost is to improving soil quality and to reducing pollution.
Problematic
For the problematic we asked ourselves questions such as:
• Why do we need to make compost?
• What should be put in the compost?
• What should not be put in the compost?
We know what to put or not in the compost as well as this impact on this one. But we didn’t know if we put or not the citrus. Some peoples saying that it’s no risk to put the citrus in the compost while others saying conversely for several reason.
We agreed on the question which is:
What are the impact of citrus fruits on compost?
For make the experiment we have make 6 mini compost from one compost. Every mini compost are composed of a fruits another of witness compost. The mini compost are:
• Witness
• Apples
• Kiwi
• Citrus
• Citrus fine-skinned
• Citrus thick-skinned
Hypothesis
Hypothesis 1
The first hypothesis is If citrus fruits produce more acidity than other acidic fruits so the compost with citrus will be more acidic than a compost with just vegetables.Experiment
We take the compost citrus (fine-skinned and thick-skinned) then compare with that apples and kiwis.
Wait for the same decomposition time and then measure the pH using a pH meter for check all the different compost to know whether the different fruits acidify the compost or not.
Results
Both citrus composts have a PH that is more acidic than kiwi but more alkaline than apple.
Conclusion
The compost with kiwis is slightly more alkaline than the compost with thick and thin citrus fruits skins. So the hypothesis is wrong, citrus fruits do not acidify the compost more than kiwis.
Hypothesis 2
The second hypothesis is if the citrus peel is more thickest than a vegetable peel, then The compost with citrus fine-skinned will be decomposed more faster than a compost with citrus thick-skinned.
The experiment for this hypothesis is weigh the mass some mini compost several times so that compare the decomposition some different compost.
Results
For exploitation of results we take into account the mass of the compost fine-skinned and thick-skinned, then we compared with of the witness compost and apple. We notice finally than the compost a thick-skinned lost in average 103,6 g his mass originals while for the compost fine-skinned he lost 63,05 g of his mass originals. The compost apple lost a larger mass than the compost citrus fine-skinned but smaller of thick-skinned. The witness compost lost almost as much of mass than compost thick-skinned.
Conclusion
The compost with thick citrus fruit skins decomposes faster than compost with fine-skinned citrus fruit.So the hypothesis but is wrong it is better to use thick-skinned citrus fruit than fine-skinned citrus fruit.
Hypothesis 3
Our last hypothesis is that If the citrus decay less faster than the other fruits then Compost with just vegetable will decay most faster than a compost with citrus.
Experiment
We use 2 mini compost 1 with the base composition and an other with citrus like oranges, lemon…During this experiments , we look at the different decomposition in the same time.
We started by putting 1g of compost in a tube of sterile peptone water.
Then we made dilutions up to 10^-10 .
then we seeded this dilutions on culture media such as :
-Chapman
-Drigalski
-BEA
-Sabouraud
-PCA
Results
Citrus concentrations are all lower than the control (except for BEA) at the beginning and then become higher afterwards.
Conclusion
Compost with just vegetable will be decomposed most faster than a compost with citrus. So The hypothesis is false because citrus-containing compost has a lower CFU/mL concentration than the control compost.
General conclusion
So we can conclude that we can put citrus in the compost safely.
