ng 
  
  
  
A possible solution to the problem of separating the effects of soil type and 
land use would be to develop a parametric classification for both, ie. an 
erodibility index and a land cover index. It is hoped at a later date to 
obtain further results by using such indices but there are serious problems in 
developing a cover index that adequately reflects the subtle variations in the 
current, and rather complex: land use in Jamaica. 
The lack of correlation between slope and erosion indicates that a heavy 
investment in terracing and other related engineering works would not be cost 
effective. Although the close correlation of certain soil types and land uses 
inhibits a study of their relative and separate effects on the rate of erosion 
it does not pose a serious problem if the aim is to produce recommendations 
for future land use. 
It has already been noted that it is not sensibly possible to modify the 
characteristics of the soil. We are left, therefore, with crop type and 
management as the variables over which man has sufficient control to effect 
some change. The recommendations made here are therefore framed accordingly. 
Among the more significant recommendations are those relating to sugar cane. 
Estate sugar accounted for 8.7% of the land use in the study area, but for 
some 22.2% of the eroded land. Small-holder sugar occupied some 0.6% of the 
study area and accounted for 0.5% of the eroded land. The difference in the 
amounts of eroded land associated with the two types of sugar cane production 
are all the more striking since the estate sugar is overwhelmingly grown on 
flat, highly fertile land, whereas small-holder sugar is grown on less fertile, 
often steeply sloping land. If the crop is the same it must follow that there 
are significant differences in the management practices. Ground observations 
confirmed that estate sugar is characterised by clean tillage, a disregard for 
natural drainage channels, and a habit of ploughing perpendicular to the 
contour. Small-holder cultivation is characterised by good ground cover and a 
clear regard for natural drainage. Ground observations did, in fact, confirm 
that small-holder cültivation is, on the whole, conducted in such a way as to 
minimise the risk of serious erosion. Multi-cropping is widely practiced as 
is mulching; both strategies tending to reduce erosion hazard. Innis (1961) 
made the point that Jamaican peasant land use was as efficient as it was 
possible to be, given the small size of the holdings, and the low level of 
capital input. The results of this study support this view. It appears, as a 
result.of this study, that if soil erosion is to be controlled, and fields 
maintained, the large estates will need to adopt similar management practices 
to those of the small-holders. 
References 
Collier P & Collins W G, 1980, The Classification and interpretation of land use 
in the humid tropics, Comm VII, ISP, Hamburg. 
FAO, 1979, Agriculture towards 2000; 20th Session of the FAO General Conference, 
Rome. 
Greenland D J, 1977, In Greenland and Lal, eds, Soil Conservation and management 
in the humid tropics, Wiley, London. 
Hudson N W, 1957, Erosion Control Research, Rhod Ag Jnl 54 (4). 
Hudson N W, 1977, In Greenland and Lal, eds, Soil Conservation and management 
-in the humid tropics, Wiley, London. 
Innis D Q, 1961, Canadian Geographer V(2), pp 19-23. 
Kovda V A, 1977, Soil Loss: An overview, Agro-Ecosystems, 3 (1977y. 
Vernon K C & Jones T A, 1958, Soil and land use surveys No 1, Imp College Trop 
Agric, Trinidad. 
Wischmeier W H & Smith D D, 1980, A Universal Soil-loss equation to guide 
"conservation farm planning, Trans 7th Int Cong Soil Sci, Madison. 
943