1.1. How to prepare the field?
(1) Trial protocol and field layout
- Simplify the field design (one factor or two factors is better), less than four factors in one trial.
- Consider optimum number of treatments in each factor.
- Set up at least three replicates for the upland condition.
- Consider the balance between the total numbers of plots, the labor, and time for data collection ÂÂ(availability of human and financial resources)
Note: If one replicate has many plots and/or data to be collected in a day, it is advisable to seed one replicate per day, and the data in each replicate are taken per each day.
(2) Size of a field trial and plot size
- Understand the field size (Measure the length and width of the filed)
- Divided the field by the number of replicates
- Determine the plot size: minimum size is 2 x 2m (it is better more than 3 x 3m)
Note: the number of samples taken in a plot for growth parameters, such as plant height, the number of tillers, culm length, panicle length, the number of panicles and so on, should be considered above twelve hills (12 hills). In case of 3 x 3m, the samples in a plot should be above 20 hills.
- Determine the total numbers of plots (the number of varieties x treatments x replicates).
- Allocate the each factor in the total plots
- Design the trial according to your type of the experiment (Complete randomized deign, Randomized block design, Latin square design, Split-plot design, etc)
(3) How to set up the replications
In setting up the trial replicates it is important to consider the soil fertility. Base on the soil fertility of the field, replicates are distributed to maintain homogeneity across replicates in as much as possible.
For example: in sloping land conditions, the lower part of the field is in many cases more fertile than the upper part. The replicates should be design vertically against the direction of the slope to maintain homogeneity in the replicate.
1.2. Field demarcation
After land preparation such as; ploughing, harrowing, and leveling; we make the trial field.
Step 1: Decide on the proposed field layout
Step 2: Make the outline of the trial field
Step 3: Measure the right-angled triangle of the field
(1) Layout the two adjacent sides
(2) Map out the 1st right-angled triangle using the “Pythagorean Theorem” method (a2+b2=c2). We usually know the formula of 32 + 42 = 52.
(3) Confirm your measurement by using another point
(4) Make a rectangle by pegging at the four corners of the field
(5) Confirm the other right-angled triangle (length of both sides and their diagonal again)
Step 4: Peg on the filed outline to identify the size of replicate according to your field plan
Step 5: Peg out the plots and footpath according to your field map.