( English summary)
on the Opportunities for Development of Rice Production with the
Adoption of the System of Rice Intensification, and Evaluation of
Biological Nitrogen Fixation (in
Andry Andriankaja, Memoire de Fin d'Etudes (thesis) for the Department
of Agriculture (Agronomy), Higher School for Agricultural Sciences
(ESSA), University of Antananarivo, 2003.
was based on field studies conducted in a highland village of Anjomakely,
18 km south of the Madagascar capital city of Antananarivo, on the
High Plateau with an elevation about 1200m. Using Fisher bloc design
for 6 factors and 3 replications, Andriankaja laid out 240 plots
(all 2.5x2.5 m) on farmers' fields, with different combinations
of plant age (8 vs. 16 days), hill size (1 plant vs. 3 plants),
spacing (25x25 cm vs. 30x30cm), water management (water control
to apply minimum amounts vs. continuous flooding), fertilization
(compost vs. NPK fertilizer in recommended doses), and soils (better
clay soil vs. poorer loam soil).
plant age, hill size, spacing and fertilization were randomly assigned.
The same rice variety (riz rouge, the most popular local variety)
was used on all plots, and there was no variation in weeding treatments
(an additional SRI variable as evaluating this would have required
twice as many plots). There was no difference in yields between
the two spacing distances, both within the SRI recommended range,
so analysis of the different combinations for five factors could
be done with six replications. Five components of yield were measured
for every plot in addition to measurement of yield, adjusting for
moisture content of the paddy harvested.
A summary of
results for this research is given in the paper on Factorial
Trials in the proceedings from the Sanya conference
on SRI in 2002 Andriankaja also evaluated the effects of SRI practices
on biological nitrogen fixation, in the context of a discussion
of this aspect of improving rice production systems.