Alright I have a dumb question that I should know the answer too. I am doing an experment- I grew soybean plants and fed them different concentrations of nitrogen to see if it had any effect on their growth. I am now done with growing the plants and I would like to take the biomass. I have all the data already.
I am doing a root biomass and a stem or above ground biomass.
The data I have is:
Wet weight of plant above ground Dry weight of plant above ground Difference between the two
Wet weight of the roots Dry weight of the roots Difference between the two
Is biomass just the dry weights? Can I do anything with the wet weights of differences between wet and dry weights?
Or did I take all the wet weights for no reason? Please help, I need to run all the stats ASAP
Dear Walid,
Using dry mass would be more appropriate. Because the moisture (water) content of the samples may affect the results. Some samples may lose moisture more than the others. Particularly, if you have many samples, the ones you collect first may lose more moisture than the later collected ones.
If you measure wet mass and dry mass, you can calculate the moisture content of the samples and want to evaluate the effect of nitrogen on moisture content as well.
I recommend you to use "mass" instead of "weight" since we find the mass by weighing the sample on a scale. The unit of mass is "gram" or "kilogram" while the unit of weight is "Newton".
Best regards,
Muharrem Keskin
The only reason to use wet weight is if you measured total wet weight and then only a subsample of dry wieght with wet weight on a subsample for diffeent organs. Then the relationship between the two could be applied to the total wet weight. Dry weight is what you need for biomass,
Dear Walid
Calculating biomass based on dry weight are the right measure ,but you can measure the effect of fertilization concentration on moisture content of plants by calculating moisture percent for these treatments.
best regards
Biomass is an amount of biological matter, usually described in terms of net loss or net gain for a specific amount of time. This value is typically expressed in terms of dry weight, or it may be defined in terms of a single element such as carbon or nitrogen. The calculation can be used to assess changes to a population of individuals or an entire ecosystem. By knowing how to calculate changes in biomass, you can assess the health and fitness of a biological system, such as a forest or wetland. Biomass Calculation It is important to stipulate the time frame / period in which you are calculating biomass. Biomass is really an expression of net change - because there can be significant changes to the biomass within the designated time period. The calculation is defined as: biomass(net) = increase biomass(gross) -- decrease biomass(gross).
Article BIOMASS : An R Package for estimating aboveground biomass an...
If you are using R for your data analysis. This package might be useful. OR if you are using excel, you can simply use the formula from Chave et al. 2014: AGBchave2014 = (0.0673*(wood_density*height*(diameter)^2)^0.976/1000)
Article Estimation of aboveground forest biomass in Himalayan region...
Product of volume and wood density would give you biomass of the tree
You can use non-destructive measurement methods of biomass using digital image analysis, for which you can also measure the growth rates, vertical biomass distribution and dry matter content. For more detail, read the article A New Method for Non-destructive Measurement of Biomass, Growth Rates, Vertical Biomass Distribution and Dry Matter Content Based on Digital Image Analysis - PMC (nih.gov)
