Land resources of central Nigeria Agricultural development ...

a limit of 3% (approx. 1.5°) for mechanized farming, only Land Systems 404,
405 and 409 are unsuitable, but it must be emphasised that the remainder
contain a proportion of steeper land, usually as lower slopes (such as .
LS 431) , on which soil conservation measures are necessary and that the
gentler slopes may be fragmented by rock outcrops or ironpan cappings.
Rock outcrops are common in Land Systems 404, 405, 419 and 446; ironpan
in Land Systems 426, 447 and 449.
TABLE 13 Dominant slope and range of slopes on major facets in areas
Land
system
with five crop options
Slopes of major facet
Percent Degrees
. Dominant Range Dominant Range
404 9 3-17 5 2-9
405 4 2-10 2.5 1-6
409 4 2-7 2.5 1-4
410 4 2-7 2.5 1-4
419
426
3
3
2-7
1-3
2
1.5
1-4
0.5-2
428 3 2-7 2 1-4
431* 3 2-5 1.5 1-3
432 3 2-5 2 1-3
438 1 CK3 0.75 0-1.5
446 3 2-3 1.5 1-2
447 2 1-3 1 0.75-2
448 2 1-3 1 0.5-2
449 2 0-3 1 0-2
•Figures are those of side slopes occupying estimated 36% of land
system. Lower valley sides with irregular, partly gullied slopes
occupy 39% with slope range of 2-90°
Density and distribution of cultivation
It is clear from Separate Map 2 and Table 14 that few land systems in this
group are densely cultivated. The exceptions are isolated areas of moderate
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