Management of rice production systems to increase productivity

increase in fertilizer application. However, overall yields in 2002 were 42 %
on average higher than in 2001. The different responses to fertilizer in 2001
and 2002 probably reflected improved soil conditions following 2001 crop, as a
result of residual fertilizer and stover incorporation (Table 21).
2000
2001
2002
Table 21. Nutrient Status of Lowland Rice Soil in SRI Fertilizer
Soil pH
1:2
H2O
5.7
5.2
6.1
Trial Plot, Sapu, The Gambia
EC
mmhos/cm
0.1
0.2
0.1
Organic
Matter
%
3.47
3.50
3.80
Total N
%
0.1
0.4
0.12
108
This phenomenon of yield increase in subsequent years has been
reported in other SRI management trials in Madagascar and Sri Lanka. A
common factor being cited is a build up of beneficial microbial organisms and
improvement of soil physical properties, although these were not measured in
the trials conducted in The Gambia. However, inherent soil fertility status
appears to play a more significant role in enhancing rice productivity with SRI
management than application of inorganic fertilizer.