Biomass harvest protocol update

[Danielcalza]

• Biomass harvest and plant count
  1. Label twentyfour (24) brown paper sample bags accordinly
  2. Place 1-meter quadrat in a subplot (9 m2 unit)
  3. Pull out cover crops and weeds by hand
  4. Separate cover crops by species and weeds (not by species)
  5. Count the number of cover crop plants only, for each species
  6. Separate roots from leaves+stems for each cover crop species
  7. Weight roots, leaves+stems for each species. Weigh weeds fresh biomass
  8. Take samples of 200 to 500 g of root and leave+stem biomass for each cover crop species until a total of three (03) samples per species plant part is obtained per two rows (combine rows 1 &2, 3&4, 5&6 as needed)
  9. Take one (01) sample of 200 to 500 g of weeds biomass per row, for total of six (06) for entire plot.
  10. Place cover crop and weed biomass samples into brown paper bags, keeping stem+leaves seperate from roots and weeds.
  11. Spread remaining biomass evenly over sampled area
  12. Repeat steps 1-11 for each row, for a total of twentyfour (24) samples for the enite plot
  13. Use hedge trimmer to cut and the remaining biomass in the plot
  14. Dry down biomass measurements for 48 hours at 60C and weigh dry biomass

[Danielcalza]

Hi everyone, I wanted to confirm these methods. I am a little confused about different references and how many samples we are exactly taking.

I wanted to clarify some of the names: "unit" -the entire site? "plot" - the entire site? "subplot" - a unit inside plot.

7. Take a subsample of 200 to 500 g of root and leave+stem biomass for each cover crop species until a total of 03 samples per species plant part is obtained per plot (e.g. AG or SP plot)

- So from each quadrant measurement, we will have 01 samples from 01 cover crop(e.g Sunn hemp) of its 03 plant parts(root,stem,leaves) - So that once we move the quadrant 03 times(within the entire unit), we will have 03 samples from all 03 CC species of their 03 plant parts respectively - so 09 subsamples total?

[Thioro18]

Hi everyone, I wanted to confirm these methods. I am a little confused about different references and how many samples we are exactly taking.

I wanted to clarify some of the names: "unit" -the entire site? "plot" - the entire site? "subplot" - a unit inside plot. The plot is the 20m20m (400 m2) and the subplot is the 3m3m (9 m2)

1. Take a subsample of 200 to 500 g of root and leave+stem biomass for each cover crop species until a total of 03 samples per species plant part is obtained per plot (e.g. AG or SP plot)

The conversion factors from biomass fresh weight to dry weight exist for winter harvest but nit summer. I think it will be useful to take biomass samples for summer as well and see the difference in water contain between the two growing season. For the biomass sampling, I took 3 replicates for each cover crop. So row 1 and row 2 were for replicate 1, row 3 and 4 were replicate 2, and row 5 and 6 replicate 3. I will explain this to you tomorrow with the plot diagram in front of us. It will be easier to understand that way.

- So from each quadrant measurement, we will have 01 samples from 01 cover crop(e.g Sunn hemp) of its 03 plant parts(root,stem,leaves)

Yes, but if there are 2 species in a quadrat you need to take root and aboveground biomass for each cover crop - So that once we move the quadrant 03 times(within the entire unit), we will have 03 samples from all 03 CC species of their 03 plant parts respectively - so 09 subsamples total?

Let's us the plot diagram to figure this out. It will be complicated in writing.

[readersm]

"unit" in line 1. is the subplot. For consistency's sake, I think we can change that to subplot. I followed Thioro's row replication in taking biomass samples for drying down (combined rows 1 &2, 3&4, 5&6 for the 3 samples).

[Danielcalza]

Thank you both for the input. I have updated the Agroecosystems Methods.

[Thioro18]

Thank you both for the input. I have updated the Agroecosystems Methods.

Looks great to me!