IRRI Long-term Continuous Cropping Experiment

Local identifier
IRRI LTCCE
Years operational
1962—
Objective
Determine the sustainability of intensive rice systems with continuous triple-rice cropping, in terms of crop productivity and nutrient supplying capacity of the soil, as affected by germplasm, agronomic management, and climate conditions.
Description
The experiment started in 1962 as maximum yield experiment. It evolved into a continuous cropping experiment having 3 rice crops per year when short duration, high yielding varieties became available in mid 60s. It has a split-plot design with nitrogen fertilizer rate as mainplot and variety as subplot. It still on-going after 54 years of continuous cropping.
Data Access Statement
Available online with registration
Data Access Notes
Available on Dataverse
Data license
CC BY-NC
Data URL
https://dataverse.harvard.edu/dataverse/RiceResearch
Data policy
Yes (not online)
Organization
International Rice Research Institute
research organisation
Person
Dr. Olivyn Angeles
experiment manager
IRRI
Sustainable Impact Platform/Soil Water Environment

Site: IRRI Experiment Station

Type
research station field
Local code
Block B5-9
Location
Los Baños
Laguna
Philippines
Geographic location
14.1690361, 121.2559055
© OpenStreetMap contributors
Elevation
21 Metres
Visits permitted?
No
Soil type
vertisol
Climatic type
tropical monsoon climate
Climate properties
VariableTime periodValue (range)Units
air temperature27.28 (23.77 – 30.8) degree Celsius
precipitation2039 (1313 – 2820) millimeter

Design period: (1962—)

Design Type
Split split plot
Description
Subplots measure 8m x 8m
Design description
The site is divided into 4 blocks (replicates); each block is divided into 4 levels of N fertilizer rate as main plot; each main plot is divided into 6 plots, corresponding to 6 rice varieties as subplot factor.
Number of plots
4
Number of subplots
6
Number of replicates
4
Number of harvests per year
3
Crop
CropYears grown
rice
Factors
Factor name
Factor levels
nitrogen fertilizer exposure
DS = dry season; WS = wet season treatments. After 1991 N rates varied from those listed, but maintained the same ratios
Plot application: Whole plot
control exposure  (0 )
N0
nitrogen  (30 (WS); 50 (DS) kgN/ha)
N1
nitrogen  (60 (WS); 100 (DS) kgN/ha)
N2
nitrogen  (90 (WS); 150 (DS) kgN/ha)
N3
variety
Varieties were changed regularly to include the highest-yielding, most disease- and insect-resistant germplasm available at each point in time.
Plot application: Sub plot
Measurements
VariableMaterialUnitsFrequencyScaleComment
grain yield traitNot specifiedannual
grain quality traitsNot specifiedannual