We now know that for seeds to germinate and plants to grow and develop water oxygen and a suitable temperature are vital. Water has been dealt with in experiment 5 now lets find out what factors influence the temperature of soils.
1. Comparing heat absorption in wet soils and dry soils.
Two test tubes, hot water , 2 soil samples ( same type): one wet, the other dry, beaker, 2 thermometers
Set up equipment as shown below:
2. Comparing heat absorption in bright and dark soil.
Two small boxes 30 cms X 30 cms X 15 cms deep, each box filled with soil and marked A and B, light bulb, 2 thermometers, chalk and coal dust.
Set up apparatus as follows. Fill each box with soil and mark boxes A and B. Cover soil A with coal dust and Soil B with chalk dust. Place a thermometer 5cms deep into each soil and place a light bulb above the soils, equidistant from both. Record temperature rise @ 2 min intervals until pattern develops. Record your results.
3. Comparing the effects of aspect or slope on heat absorption.
Two small boxes 30 cms X 30 cms X 15 cms deep, each box filled with soil and marked A and B, light bulb, 2 thermometers.
Using the boxes from experiment above (2) and do the following.
Have a light shining directly over soil box A and at right angles to soil box B. Same soil type in each box. Thermometers 5cm deep in both. Again record temps. @ 2 min. intervals until a pattern develops. Is it true that fields with a southern aspect are warmer, therefore better than fields facing North, East or West ?
Record all your results carefully in your notebooks.