The hypothesis is that the wood samples that were immersed in soil will start to decay and become weaker at a faster rate.

You will inspect the dimensions of the wooden planks and divide them into five groups. You will then fill four pails with rain water, acid rain, sea water, and wet soil, and place the planks in the respective pails. The fifth group of planks will be left in a dry place. After two weeks, you will take the planks out of the pails and leave them to dry for three days. Finally, you will measure the strength of the wooden planks by applying weights to them.

You will need 20 oak wood planks, 16 bricks, 20 weights, tap water, a pail of rain water, a bottle of vinegar, 1000 grams of salt, four pails, soil, a rope, pH paper, and a black marker pen.

After two weeks, it was observed that the wooden planks that were kept in the moist soil were the weakest among the five groups. The hypothesis that the wood immersed in the soil will start to decay and become weaker at a faster rate was proven to be true.

This science project is interesting and unique because it explores the effects of different environmental factors on the strength of wood, which is an important factor in the construction of houses.

Consider repeating the experiment, this time exposing the wood for different lengths of time (1 week, 2 weeks etc) in order to study the rate at which the wood will weaken. Also, try using other types of wood like Pine, Fir, Hemlock or Birch.

These videos explain the science behind this project and demonstrate key concepts used in the experiment.