Measuring CO₂ Production Using Soda Lime:

Soil Moisture Content Data Form

For use with Protocol 8b: Determining Moisture Content

Complete one form for each soil sample.

Name(s) _____________________________ Date _______________

Soil sample ID number ____________________________________________

Soil sampling location _____________________________________________

Type of area sampled (e.g., forest, schoolyard) _________________________

Date soil sample was collected _____________________________________

Describe the soil sample (e.g., number and size of rocks and roots in sample; did the soil appear to be very wet or very dry?)

Was the soil sample well mixed? ______________________

Date and time soil subsample placed in drying oven ______________________

Date and time soil subsample removed from drying oven ______________________

or, time and power level required to dry subsample in microwave ______________

Protocol 8b, Part 1: Determine percent moisture, using a subsample.

Step 2: Weight of beaker = _____________ g.

Step 3:

wet wt of soil	=	combined wt of beaker and soil	–	wt of beaker
	=	____________ g	–	____________ g
	=	____________ g

Step 5:

dry wt of subsample	=	combined wt of beaker and soil after drying	–	wt of beaker
	=	____________ g	–	____________ g
	=	____________ g

Step 6:

moisture content =	wet wt - dry wt wet wt
=	_____g - ____g _____g
moisture content =	___________

This result is expressed in decimal form for use in dry weight and CO₂ calculations. To express as a percentage instead, simply multiply by 100.

Part 2: Adjust total sample to 50% moisture, if needed.

Step 1: Total soil weight = ______________ g

Step 2:

actual water wt of full sample	=	total soil wt of full sample	x	moisture content of subsample
	=	__________ g	x	__________
	=	__________ g

Step 3:

dry wt of full sample	=	total soil wt of full sample	–	actual water wt of full sample
	=	_________ g	–	_________ g
	=	_________ g

Step 4:

wt of water to be added	=	desired water wt	–	actual water wt
	=	______ g	–	______ g
	=	______ g