Management of rice production systems to increase productivity

Figure 10. Grain Yield at Different N Application Rates and NuMass
Predicted Yields at Different NUE Values, 2000, 2001, and 2002 Cropping
Seasons in Brikama, The Gambia
The predicting N for upland rice, NuMaSS should use yields from the
drier year; 591 mm rainfall. The amount of precipitation should have a more
dominant role in predicting N for upland rice in semi‐arid regions. The NUE
appears to be high during drier years. Positively correlating predicted N
amount and rainfall amount should be considered for NuMaSS N prediction
for upland rice in the semi‐arid regions. Applied N also needs to be managed
in a different way.
2.2.4. Conclusions
All the low‐input varieties performed better than the local check
(Peking); however WAB377‐B‐16‐L3‐LB and WAB56‐125 gave the highest
most stable yields.
The best NUE (65‐85g grain per gram N) was recorded with WAB56‐50
at low‐input (40‐40‐40 kg/ha NPK) fertilizer application rates.
Increasing biomass production or harvest index, or both resulted in
yield increases. However, grain filling did not necessarily depend on biomass
accumulation, but the possibility for the plant to utilize N already
accumulated in the biomass for grain production. This is indicative of the fact
that research to increase rice yield potential in the upland should aim at
increasing biomass production as well as carbohydrate translocation potential
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