Questions related to Field Experiments
How do i calculate the infiltration rate, Darcy velocity and pore water velocity for a field experiment, supposing i poured about 500 litres of my sample on a 3m by 3m field area of soil. I also took soil samples at various depths from 0-150 cm and had porosity for the different depths. So i need proper calculation and paper referenced on the method used.
This experiment would be conducted with:
1. Five paddy varieties
2. 4 levels of bio fertilizer (ex: control, 100, 200, 300)
3. A field experiment was conducted to study the growth and yield of rice.
i have read many peer review articles mostly they have written giving 200mm of water for X-crop in his total growth period. my question is that
200mm means amount of water in one acre or one hector or per plant in open field experiment?
please guide me about this matter
Why did bio-aerosols not become a commercial alternative to silver iodide in cloud seeding?
It is the agri entomology experiment conducted in two different contrasting locations for two years and two seasons per year. The data collected from the experiment was number of eggs, larvae, pupa, adult insect
Which statistical test should e follow to significant difference between the treatments in field experiment, DMRT to Tukey HSD
In a field experiment if there is possibility for both designs factorial RBD and Split plot design, and both qualifies as per degrees of freedom, then what design should be choose and why?
Drought treatments in field experiment include 1/12P, /1/4P, 1/2P, 3/4P , P. P represents the plot receiving natural precipitaion. I do a linear regression between drought treatments and response variables. The reviewer think that this analysis was inappropirate. Can you help me? explain why
I am planning field experiment and wish to collect RGB as well as multi spectral images for crop monitoring.
Considering images shall be acquired by UAVs, I wish to know if any guidelines exists for conducting field experiment.
Hello statisticians in the house,
I am collecting samples from an already established field experiment with the following research details
Plant cultivars = Whole plot, 3 levels (cultivars A, B, and C)
Grazing level = Subplot, 2 levels (Grazing vs no grazing)
Block= 4 blocks
However, for my current experiment, I am only interested in the plant cultivars without the grazing effect. So, I collected the plant samples at no grazing level. How do I go about my statistical analysis? Should I treat it as a one-way ANOVA with blocking as a factor considering that there is no subplot factor anymore?
Many papers suggest having a minimum error degree of freedom of 12. When a new crop variety is evaluated for agronomic performance with a local check or control, number of replications needed to generate a degree of freedom value of 12 is 13. That is, number of treatments (n-1) X number of replications (r-1), which is (2-1)X(13-1). I maintain this minimum degree of freedom for experiments with three or more treatment, however I not sure in the case of a paired field experiment. I would be grateful for your support and suggestions.
Dear colleagues, I would like to ask you for advice. I would like to see if long-term field trials can answer the question of how a changing climate affects wheat yields and whether a changing climate will affect different localities in different ways. I have the results of yields from a long-term field experiment (1980 - 2018) and information about the weather (temperature and precipitation). However, a single field trial cannot provide such an answer. This is due to the interaction between the weather and the different varieties used in the experiment. It is therefore not possible to distinguish between the benefits of varieties and changing weather. But I also have the results from other experiments. We run three long-term experiments, each in different soil-climatic conditions. These experiments have the same methodology, the same fertilization treatments, the same preceding crops, and the same varieties of wheat used during the time. Would this be the way? On the other hand, each wheat variety will have different results depending on soil-climatic conditions. An opponent easily drops such an article from the table. The more I think about it, the more desperate I am. I wanted to somehow use long-term results, a long time series, obtained under defined conditions (experimental data), but the interaction between the varieties and the weather forms an impenetrable barrier. Can you think of an analytical method that would evaluate such data in a reasonable way? For your info, I tried to use different models and the cubic model provided nice results, showing a kind of stagnation (Ivanovice, chernozem), decrease (Caslav, Luvisol), and increase of yields (Lukavec, cambisol) in the last few years when warm seasons began. But again, different wheat varieties were used between 2011/2014 and 2015/2018. I have also evaluated if the season was cold, normal, or warm or dry, normal and wet. Thank you if you have read it and you have a tip on how to use and evaluate such data and provide the answer to the question of how climate change affects wheat yields.
I'm looking for an algorithm to help automatically track soccer ball in a controlled field experiment (cameras positioned near to the ball) and output its time-series 2-dimensional coordinates. While we have found very efficient methods to do this in human movement features (e.g. OpenPose), we are experiencing some difficulties to found similar methods to detect/track other objects (e.g. ball). If you have some positive experiences with a given method, please let me known. Thanks in advance. Luiz H Palucci Vieira.
The conservation agricultural field experiment with three treatments is being carried out in black cotton soil of central India for the last three years. Which statistical design is best suited for comparing two/three years of field crops and nutrient data? Treatment includes 1. Irrigation methods (2), 2. Sowing machines (3) and 3. Residue retention (3).
I have a question regarding manipulation checks in field experiments. Can you please share if you have ever done one? Are you aware of any published studies that included one?
Usually, the price to pay for the natural setting of a field experiment is that we give up some control, including (I thought) manipulation checks. But lack of a manipulation check in a field experiment came up recently in a manuscript review and I would love to read and learn more about it. Input from all disciplines (especially social sciences) is welcome! Thanks!
I have some interesting data testing Kefir and some food effects in mice models of obesity and malnutrition. However, I just found Open Access journals and the Brazilian government it is not paying for that. Could you suggest me good journals without publications fee?
Kindly suggest which statistical experimental design is suitable for a field experiment having two levels of irrigations (sprinkler and furrow), three levels of sowing machines (zero-till-drill, raised bed shaper-cum-planter and conventional seed-cum-fertilizer drill) and three levels of residue loads ( 30%, 60% and 100%) with three replications?
I want to analyse my experimental data of field experiment in botany,which includes plant growth.I want to apply standard error and critical difference? I want to know what all parameters do I need to findout the critical difference? And what is exactly Critical difference?
(1) A person who constantly works on secondary data (in scientific research) is considered a scientist or data analyst?
(2) In a world of limited funding and "publish or perish", should scientists shift towards the secondary data approach?
I was studying plot-based comparison of two treatments regarding their contribution to sediment response. the slope is also another factor going to consider in the field experiment. the plot is designed in such a way that the runoff and sediment from the plots direct into the runoff collection tank. Here I want to take A sample of sediment concentration from the storage tank after each rainfall events occurred. but I am really confusing how to sampling and what equipment should I use while sampling. and also to what or at what depth should I take the sampling from the rectangular tank?
I want to really thank you for your support, guidance and your constructive suggestion regarding the issue.
Say you have 50 randomly selected flag leaf samples from each of your trial plots in a field experiment. You have their dry weights and you determined micro-nutrient and macro-nutrient content by ICP-AES. Is it possible to determine nutrient uptake efficiency, specifically that of phosphorus, from this data? If not, what type of information can we infer from this data?
We have conducted a field experiment to evaluate the effects of infiltration trenches and improved grass species on biomass productivity and soil quality. The result indicates that water conservation through infiltration increased biomass productivity while the available form of nitrogen (ammonia and nitrate) content decreased, but the total N content increased. What would be the possible explanation? The reduction in available N could be related to the increased uptake by the grass, and possible denitrification due to increased soil moisture content because of infiltration trench. The organic matter content has increased with the increased biomass- can this alone explain the increase in total N?
Thinking in terms of a social setting such as a dance, a concert, a meal, if an experiment were to be designed in such a way, how can the method be validated? Similarly, what role would reliability play in an experiment set in a social setting? How can you recreate social settings for further empirical study?
I would love to read some examples of studies if you are familiar with any!
We have set various in situ experiments with epiphytic orchids seeds. We put fresh orchid seeds inside nylon mesh packets (ca. 1000 seeds per packet) along with a bit of moss (to improve moisture), and then located those packets on tree branches close to mother plants. After 1 year, we retrieved the packets and open them to locate germinating seeds, but moss and lichens have grown inside of the packets, plus there is a large accumulation of detritus and dirt, so it has been very difficult to locate the seeds (only finding <5%). We don't expect mortality/decomposition rates to eliminate 95% of seeds.
Do you have a recommendation on how to locate those seeds?
We have tried the following:
1) series of washes and filters to remove bigger pieces of moss and lichens
2) washes and low centrifugation
3) centrifugation with filters
4) dilution of centrifuged materiales in several petri dishes.
We wish to use a method that wont damage the putative fungi growing in the germinating seeds / protocorms.
In a research having multiple treatments, say 4, there would be 4 treatment groups. In comparison, is one control group enough or should it have 4 control group.
Please note that all the groups here are randomised and homogenous.
is it okay to get data from ansys or abaqus and build a model of neural network Or I must get the data from a realistic field experiment ?
For my master thesis i'm conducting a field experiment.
I have two dependent variables:
- The first is dichotomous (yes/no)
- The second is continious (number of seconds)
I only have 1 independent variable with three levels (categorical).
Now, i don't know which method is appropriate. Several topics have been opened about multiple DV's where i'm reading on MANOVA, multiple regression and canonical correlation.
Can anybody help which analysis is most appropriate? I will do my analysis in R.
Thank you in advance!
I analyze the microbial community composition from soil samples collected in an agricultural field experiment. Within this field, there are 3 plots (randomly distributed in the field) and for each plot, we collected soil samples at 2 depths and 3 different compartments (comp). We have a total of 18 samples. BUT I only have one observation per sample unit. So, basically the replicates are the plots. My first idea was to write the following model with adonis:
x ~ depth + comp
With plot factor considered as replicate. But I am not sure it's right because the plots are distant (several meters). They are not true replicate, right? Then, after I had discussed with some colleagues, it turned out that I should maybe use the following model:
x ~ plot/depth + plot/comp + plot
depth and comp being nested in plot. But in that case, I have no replicate at the lowest level, and it might be a problem for a permutation test... I don't know how to solve this problem. The experimental design is a bit tricky because we have no replicates at the lowest level. Therefore, I don't know how to deal with the statistic model.
If anyone can help me I would greatly appreciate :) Thanks for your time!
I need to enter data in Hydrus 2D.
Solute was incorporated into the soil by field experiment applying urea and ammonium solution.
Results from laboratory are expressed in mg/kg and solution used in field in mg/L
In what can best be described as a naturally occurring field experiment, it was noticed that soldiers who flew home directly from the 1982 Falklands war adapted less well than those who returned a week later by sea. Unfortunately, this is an anecdote. No actual measures of reverse-culture shock were taken. I'm wondering if the speed with which repatriates return affects their readjustment. Anyone know of any studies in which a period of decompression helps a major life-space transition of some type? Thanks in advance.
Is the artificial drought stress creating process same for pot experiment and field experiment?
Any one have the method for calculate this parameter in field experiment. or this is just for wheat crop ?
Hello, Is it generally true that effect sizes are lower for ecologically valid field experiments compared with controlled lab experiments?
I'm not sure about this and I'm just trying to understand why the effect sizes in my field experiment was much smaller than my experimental self-report study, on the exact same IVs and DVs of course. Do you know anything about this? Some sources on this would help very much.
Many thanks for your help in advance!
Suppose, I have 30 possible isolates of Azotobacter spp. I need to narrow it down to below five on the basis of their effect on rice vegetative growth ( maximum effect of an isolate in growth). If I want to go for traditional field experiment that will be a hell a large experiment and will take around five month to reach any conclusion (I want to do field experiment after narrowing it down to a feasible amount).
If anybody has any idea about in vitro experiment , less time consuming and effective, suggestions will be appreciated. Thanks.
I am interested in the building a rainout shelters to exclude precipitation for field experiments.
Can anyone offer advice on materials, suppliers, and construction of shelters? I am interested in building about 48 units that look something like the shelters shown on this page:
As far as I can tell, these units are not commercially available as kits. If anyone has experience with building these, can you share your basic design and materials used?
I have been carried out a field-experiment testing some criteria of vermicompost nutrient changes in vermicomposting. CV value was about 15-20%. Should i keep this data or test one more time?
I started my PhD this year where I'm studying how hunting, parasites and vegetation influence the local distribution of ungulates. I'm using 2 species of antelopes that use similar niche (grazers) and live in an enclosure of 4600 ha with no natural predators. I would like to collar 10 females per species with gps devices, but I know these devices are expensive and I don't have the budget for buying 20 devices.
I want to get information from 4 locations (early morning, noon, afternoon and evening) per day during a period of 6 months. I also want to take the data from the devices with out capturing the animal (transmission of data to cell phone or other gps or drop-off system?), because I will not be able to catch the animals again after collaring them.
Do you know anyone who can give me advice on how to build or where to buy these devices with a limited budget?
I checked Mataki project (http://www.mataki.org) and I contacted people from Blake Allan paper (https://www.researchgate.net/publication/277385807_A_cost-effective_and_informative_method_of_GPS_tracking_wildlife ) but I would like to know if you have more ideas.
I was conducted two field experiments in two consecutive years in order to estimate genetic diversity analysis among forty fourth genotypes of lentil (lens culinaris M.). Morphological characterization was done based on different parameters like plant height, pod per plant, seed per plant, 100 seeds weight… The experiments were carried out following an Alpha Lattice design with fourth replicates. Data were recorded from both years. I would like to know if generalized linear mixed model (GLMM) is applicable in this case, considering a genotype as a fixed effect and a bloc as random effect.
Thank you for your response.
How to analyze the data collected?
Can active search of Naja kaouthia in nests or rat hole be used to estimate population size?
I'm shopping for field photosynthesis measuring systems. The LiCOR 6400 and PP Systems CIRAS-3 both have the option of estimating apparent electron transport rate (ETR) and PSII yield based on fluorometry: basically looking at Chlorophyll fluorescence. The WALZ PAM 2500 is exclusively a fluorometer. In contrast, the LiCOR 6400 and PP SYSTEMS CIRAS-3 are mainly estimating photosynthetic rate based on differences in CO2 and H2O vapor.
Have people tried both fluorometry and gas exchange approaches to estimating photosynthesis? What are the relative advantages of both approaches? Do you really need both systems to get an estimate of photosynthetic rates? What are the relative errors?
We had several samples losses of Barber pitfall traps in our Alpine sites due to marmots that were attracted by the conserving solutions or trampling cattle. We used ethylene glycol, but we switched to the non-toxic propylene glycol, unfortunately both have a sweet taste, the latter with reported with less attractiveness.
I wanted to ask the community, if there are tips for metal cages that cover the pitfall traps.
I already designed some prototypes (I love to tinker :-) ) and ideally the cages should:
- not influence the catch pattern and rate
- be robust but also of light weight
- not be too expensive
I want to create range of light intensities in the 2×5 m plots under field condition. Which materials can be suitable for this purpose?.
Im working in a field experiment with 20 traps (pitfall traps to collect ground atrhopods) in a treatment field and 20 traps in a reference field (so potentially spatially autocorrelated).
I performed a nMDS (non param multidimensional scaling) plot to assess multivariate ordination of those samples and I plotted also 95% confidence ellipses to visualize effective discrimination between the treatment and the reference field. Then I would like to have a statistical measure of this discrimination so my idea was to perform a perMANOVA (adonis function in R software) to test dissimilarity between fields. So my question is:
-Can I use perMANOVA with such experimental design? If not, is there a way to deal with such autocorrelation? Suggestion on alternatives?
Thanks a lot
For purposes of scientific reviews and to obtain a better sense of the state of biochar implementation outside of broad-field agriculture, I am interested in learning about any prior or ongoing field experiments on biochar effects on plant productivity, soil processes, and biogeochemistry. A brief "meta-data" description would be valuable (location; year implemented; size of treated areas; biochar dosage(s); plot replication; type of biochar used including feedstock, pyrolysis method, and peak temperature; soil type, including texture and pH; ecosystem or target plant species examined).
Depending on responses, I would consider collaboration on a review with contributors.
I have attached a file with my lab's ongoing field trials as a template.
I am looking for a small mobile unit that could be used to perform DNA extraction, PCR and gel or capillary electrophoresis in the field, i.e. Not in laboratory conditions. The purpose of the kit is to perform species or individual ID. Samples would range from muscle to hair and PCR would use mtDNA or STR primers.
I am basically an Agribusiness professional, interested in Random Field Experiment projects. Kindly help me to start with this
We would like to observe the development of single insects on plants in the field. The insects usually settle on the bottom side of the leaf. Leaves are quite large (about palm-size) and more or less waved with some strong veins. The experiment will run about one month during summer, and therefore possible physical damage by the cages, rains and wind are additional challenges (the standard setup with metal clips and sticks can be problematic, since it is unstable and susceptible to wind especially with upper leaves which are about 30-50 cm above ground).
Now we are unsure what type of caging to use and a few ideas we had so far are:
- Light-weight clip-cages without sticks (still fragile setup, mounting only possible at leaf edges in larger leaves bec of clips)
- Gauze nets (covers whole leaf; prone to getting wet during rain, to heavy then or insects might drown)
- Perforated plastic bags (too high humidity and temperatures within bag)
Do you have any better setup for such caging or another cage type or an idea how to mount a clip cage safely on such leaves in the field?
Thanks for any input.
We have conducted an experiment to check the reliability of postion, velocity, and altitude as obtained by GPS tracking data (see attachment). We did an extensive search of the literature without finding much. Anybody aware of papers concerning extensive, experimental testing of the reliability?
Technical Report Reliability of GPS based traffic data: an experimental evaluation
We are trying to learn more about any kind of species interactions (competition, predation, disease transmission etc.) between native and non-native (invasive) crayfish in the eastern United States. We are designing some laboratory and field experiments to assess the potential impacts of invasive on natives (focusing on Virginia), so any additional information would help us do a better job with new research program in my lab. Thanks.
I want to use a mobile eye tracker for some real world experiments and still trying to search for the best option for it. Any opinions or experiences about this device?
When we use the dirac delta function to solve the paradox of divergence of a 1/r^2 field, we say that divergence of the field is infinity at r=0 as delta function reaches infinity at r=0 which means that there is infinite flux passing through a minute volume. But since it can be mathematically proven that a point charge is nothing but a uniformly charged solid sphere with a very small radius, the electrostatic field at r=0 is 0, which contradicts the result obtained using dirac delta function. Why?
Looking to freeze down biopsies in the field, collected from rare wildlife species. A Mr Frosty works well in a lab set-up, using a -80C freezer, but not suitable for field work. A Liquid Nitrogen flask can be taken into the field. Any ideas as to which company or supplier may have such an apparatus available?
I am looking for a possibility to survey insects in the field using video cameras, possibly also at night. Does anybody have some good or bad experience with this kind of survey and some indications about possible material to use?
I measure Net Ecosystem Exchange in peatlands and I'm having problems with the temperature inside the chamber. Right from the start, it increases dramatically. Such an artefact affects photosynthesis, which makes the measurement unrealistic and, thus, unexploitable. Has anyone been through such a problem already? Any idea how to resolve it? Any references about this problem?
Experiments could be laboratory based and theoretical in nature, or applied field experiments that provide valuable cross-site comparisons, could be economic, ecological, psychological, or all of the above. Experiments could be large scale, centralized projects (such as a "Biosphere II" approach) or smaller precision research tools.