This experiment will be conducted in a soybean crop at Waterman Farm and in prairie at the Chadwick Arboretum

1) Vertical Distribution of Biomass

Aim

To measure the uniformity of biomass (leaves, stems, seed) distribution, above-ground

Method

1. Measure average canopy height, and calculate the heights representing 50%, 75% & 90% of canopy height 2. using shears, starting from the top layer (i.e. 90%) clip vegetation for a measured lenght of planted row (record sampled length and row spacing to calculate sampled area) 3. continue sampling lower layers 75% and 50%, and then sample remaining material to groundlevel. 4. In the lab, separate leaves from stems and measure leaf area for each layer using the LiCor 3100 area meter 5. separate stem and seed components, and dry all components (including leaves), weigh in 48 hrs

(click to enlarge 94 kb) (click to enlarge 93 kb)

Results

1. Plot the vertical distribution of total biomass
2. Plot the vertical distribution of leaf area

Discussion

• What was total biomass? Is its distribution linear? What is the significance of this?
• What was total leaf area? Is its distribution linear? What is the significance of this?

2) Light transmission

Aim

To measure light penetration into a crop canopy and relate this to leaf area

Method

1) Using the light bar, measure light intensity at the canopy surface, at 90%, 75% & 50% of canopy height, and at ground level. <instructions for the LI1000>

Results

1. Plot the vertical distribution of light intensity
2. Plot the light intensity vs Leaf area?

Discussion

• Was light intensity uniformly distributed down the canopy? What is the significance of this?
• Was there any relationship between light intensity and canopy leaf area?

Report

Your lab report should plot at least 2 measured variables (biomass, LAI, or light intensity)

You should have approximately 300 words to explain the figure: 100 words describing the Method (what you did), 100 words describing the main result (what you got), 100 words of Discussion and interpretation (what it means) and at least 1 relevant reference.

The report is due next Monday