Management of rice production systems to increase productivity

The research objectives are as follows:
1) To assess the productivity of WARDAʹs low‐input upland rice varieties
as influenced by different nitrogen levels;
2) To determine if rice cultivars differ in N‐use‐efficiency;
3) To determine if the improved low‐input varieties indeed possess a
greater nutrient‐use‐efficiency than conventional varieties;
4) To find out what are the most important operating mechanisms that
result in improved nitrogen efficiency;
5) To identify which variety is more stable and higher‐yielding for use in
The Gambia under conditions of low fertility and less intensive
management practices;
6) To help upland rice breeders focus on the more important physiological
and morphological characters affecting nutrient‐use‐efficiency in the
Sahel.
7) The results will also be used to calibrate the Nitrogen Module of the
Nutrient Management Support Software (NuMaSS) for the Sahel
region.
The hypotheses are as follows:
1) The yields of the Low‐input varieties will not decrease significantly
with decrease in N‐fertilizer input;
2) The Low‐Input varieties will yield higher than the conventional check
variety at low‐input N application rates;
3) The Low‐Input varieties have a higher NUE than the conventional
check variety;
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