I've been looking around for some common relationships between above ground biomass of vegetable and legume crops (peas, tomatoes, beans, Swiss chard) and easily measurable growth characteristics. My application is in small-size greenhouse plots. I don't need a remote sensing method. I just need a relationship between easily measured characteristics like leaf count, leaf size, fruit count, stem height, stem diameter, and plant volume. I just haven't seen any easy-to-use relationships or models out there to relate these characteristics to dry above-ground biomass. Are there standard relationships for this, or is this something that most people determine by experiment for each crop they are using in a project?
Dear Nathan
The regression analysis is used to determine one of the measurements using measurement data or other(s). This is done if the determination of the biomass of trees and shrubs roots, that are difficult to uproot, through relations between the root biomass of the root and the size of the plant or its length or the biomass of the shoot or. ........ It is one of the non destructive means of natural plants. As well as leaf areas through its length and width. In the case of the plants mentioned, all plants are cultivated and the number of plants to be used in analyzes and measurements is calculated in the beginning of the experiment and also because it is easier and less effective on the species extinction as natural plants. The crops in question, change their measurements based on the factors they are exposed to. The root length and its biomass changes by soil quality, abortion, nutrition and other factors, as well as the growth stage. Therefore, I recommend measuring directly without resorting to regression analysis.
I think the best way is to measure ground cover percentage (GC%) either by light sensor bar or taking photos for the canopy from above distance and expose it for image analysis to determine the percentage of ground cover.
By using GC% and climate parameters such as temperature (Max and Min) and humidity as inputs in crop growth models such as aquacrop (provided on the web of FAO) you can estimate the progress in plant biomass production. you can confirm your results by the destructed samples in the end of the growing season.
Good luck
Dear Nathan Howell,
You can use Image processing technique to measure the plant above ground biomass parameters like leaf count, leaf size, fruit count, stem height, stem diameter, and plant volume without killing the plant.
You can use portable leaf area meter to measure the area of some leaves and estimate total plant leaf area using this average leaf area multiplied by total number of leaves. Then you can use any plant growth model to calculate total plant biomass production using leaf area and climate parameters as inputs.
You could use a sunfleck ceptometer to non destructively monitor canopy growth and above ground biomass production.
See https://www.delta-t.co.uk/product/sunscan/
If you standardize your plant population density the biomass can be estimated based on exploring the relationship of plant height to total dry matter. After you have the relationahip based on phenology and plant height you will be able to estimate the total dry matter based on the pre determined relationship. To develop the relationship you will need to harvest and dry samples once that relationship is determined the plant height will give a pretty reasonable idea of the actual dry matter. There is literature on this it is used for cover crop estimations.
Low-cost non-destructive image-based phenotyping methods for obtaining biologically meaningful information with minimal environmental and experimental noise are available these days.
One of my friend had his Master's research on "IMAGE BASED PHENOTYPING OF CROP GROWTH IN WHEAT"
You can read his work here Nathan Howell Sir
http://krishikosh.egranth.ac.in/handle/1/5810034073
If you want to measure leaf area, I recommend LeafByte. It's a free and open source app for iPhones and iPads. It measures leaf area and herbivory levels much more quickly than ImageJ and related software. It also automatically saves your data for you in a spreadsheet.
You can download it in the app store or read more about LeafByte at the website below. You can also check out the FAQ page for ways to measure leaves non-destructively and in the field.
https://zoegp.science/leafbyte
https://zoegp.science/leafbyte-faqs
Disclaimer-I was involved in making this app, but since it's free, I make no money from its use.
Above, @Paul Reed Hepperly suggested that the relationship being sought by this question is that "...the plant height will give a pretty reasonable idea of the actual dry matter." He notes that there is literature to support this. My experience is largely in survey statistics where you can use a probability-of-selection-based (design-based) approach to estimate a total from a sample, or a model-based approach to "predict" (the word used for estimate with regression/a random variable) when you have regressor data, or perhaps model-assisted design-based methods. Here it seems that regression can be used to improve the estimate/prediction of total above ground biomass from a sample, if you have plant height data for the population, and it will provide the relationship sought by this question. So then the estimated variance of the prediction error could be found (don't forget heteroscedasticity) for individual predictions, and for estimating/predicting the total above ground biomass. The regression model then could be examined for "fit" using a graphical residual analysis (with the predicted y on the x-axis, and estimated residuals on the y-axis), and if data not used to estimate the regression coefficient(s) are then checked to see how well you predict them, that would be further good evidence.
Just some thoughts.
It would be good, Nathan, if you let us know how your project turns out, if you might.
Cheers - Jim
- Badges
- Science topic
- Similar topics
- Agricultural Science
- Agronomy
- Crop Science