What is an addition plot?
Addition plots are demonstration plots in farmers' fields. In this technique farmers change one factor compared to his or her usual practice to identify the potential of the new technique. Treatments include:
For example, a potassium (K) addition plot receives more fertilizer K compared to the usual practice. This demonstrates the effect of additional K on yield, grain quality, lodging resistance and/or pest incidence.
When to use an addition plot?
Addition plots should be used if a treatment is expected to perform better than the farmer's usual practice. Both farmers and researchers can use this technique for field demonstrations.
How to establish an addition plot?
You can install an addition plot as a small (5 m x 5 m) plot inside a field. Treat the whole field as usual (farmer’s practice), but apply the additional treatment to the addition plot.
How to use the addition plot technique?
The addition plot technique helps farmers overcome major agricultural constraints in the field. The technique is sometimes used when evaluating a promising innovation, such as a leaf color chart (LCC) for nitrogen (N) management (see figure below). In this example:
See IRRI's Leaf Color Chart fact sheet for more information about using the LCC.
What are the limitations of addition plots?
Note: Recommendations for P and K rates can be developed using the omission plot technique (see IRRI's Nutrient Omission Plots fact sheet for more information).
Developed with input from RJ Buresh, C Witt, and M Bell.