paulojomaje,
I am guessing that your use of the English language may have caused some misunderstanding. When you say “THE EFFFCT OF HEAT ON THE MAGNETIC SUSCEPTIBILITY OF TOPSOIL” and when you say “Farmers in my place bake the topsoil/farmland during planting season before the actual planting of seedlings. The baking( gathering of woods and grasses and burning them on the farmland) process definitely alters the magnetic susceptibility of the farmland depending on the intensity of baking.” this may cause confusion in some people who read your post.
I will attempt to find different words for what the farmers do there and then I will make a guess about your project.
1. The farmers are not baking the soil. They are burning grasses and woods on the soil.
2. The ashes from these materials fertilize the soil and increase the crop yield. It is not the heat that changes the soil.
I found this using Google search:
“As a fertilizer, wood ashes are a good source of potassium, phosphorus, magnesium, and aluminum. They typically contain less than 10% potash, 1 % phosphate, and trace amounts of micro-nutrients such as iron, manganese, boron, copper, and zinc. (Wood ashes do not contain nitrogen.) The exact chemical make-up of ashes varies according to wood type (hardwood ashes contain higher potassium levels than softwood ashes). If compared to a commercial fertilizer, wood ashes would probably read about 0-1-3 (N-P-K).
http://www.thriftyfun.com/tf000251.tip.html
3. My guess: Since the trace elements such as magnesium, aluminum, iron, manganese, copper, and zinc may affect the magnetic susceptibility of the soil then your thesis could be logical.
4. I am not qualified to say if these “trace” elements in very small amounts would indeed affect the characteristics of the soil enough to measure a change in the magnetic susceptibility. If yes, then you may have a viable hypothesis. Please let us know here how the experiment goes.
Cheers, Bobbywhy