Agriculture Reference
In-Depth Information
in 1980 and 1993, low temperatures damaged the Korean rice
crop seriously, with grain yields dropping by 26% and 9.2%,
respectively, compared with the national average yield on either
side of these years (Fig. 42).
5.5
5
4.5
4
3.5
3
2.5
2
1970
1975
1980
1985
1990
1995
2000
2005
Year
Fig. 42
Variation of rice yield in Korea.
Cold injury and damage are of varying degree and types
mostly not known visibly, can only be analyzed. Some known
injury is depicted hereunder (Table 31).
In the soil organic matter is depleting gradually thus
application of organic matter is of most importance. Organic
matter not only improves soil structure but also provides trace
elements suffi ciently apart from supply of major nutrients to
the crops. Thus, in rice a combination benefi cial effects are
evident (Table 32).
