The result of the study in Table 2 revealed that in operating sensor technology, the farmer needed the techniques that could enable him calculate vegetation index , drive ground-based mounted device, issue appropriate command to remote sensor, manipulate the Graphical User Interface of the sensor,monitor the crop yield, interpret data and make suggestions among others. The findings of the study were in conformity with the findings of that there is need to generate maps of the soil with its characteristics which included grid soil sampling , yield monitoring, and crop scouting. The author further found out that strategically positioned sensors collect data in the form of electronic computer databases which gives birth to the Geographic Information System for statistical analyses of data and determines variability of agricultural land with respect to its properties.

The findings of the study were also in line with the findings of that an effective method used to easily interpret remote sensing data is calculating vegetation indices.Shifting cultivation or slash-and-burn agriculture is a global agricultural practice that affects an estimated arable land area of 1500 million ha . It is the traditional method of upland rice cultivation in most parts of West Africa and in the humid and sub-humid tropics. This is a practice where a piece of forest is cleared and burnt for cultivation for a period of two to three years without fertilizer input and then leaving the land under natural fallow vegetation for a much longer period, usually greater than fifteen years, to restore soil fertility .At the onset of the cropping phase, when vegetation is burnt, almost all biomass carbon which is a potential source of soil organic carbon is lost as well as a significant amount of nutrients such as nitrogen and sulphur contained in the biomass.

During the cropping phase, inappropriate soil management practices could lead to accelerated depletion of soil organic matter and nutrients resulting in rapid depletion of soil fertility.During the fallow, the accumulation of biomass on the soil surface and its gradual decomposition does not only release nutrients but provide an energy source for the soil microbial populations and improvement of soil aggregate stability and structure, bulk density, infiltration capacity, cation exchange capacity, and soil organic matter. Also,nutrients are taken up from deeper layers by roots of trees and shrubs and returned to the top soil via litter fall and root senescence.Restoration of soil fertility by this means requires several years of fallow and has become inadequate in the face of increasing populations and food demand as well as competing alternative land uses. This has led to considerable reduction in the fallow period and the cultivation of marginal lands.In Sierra Leone, the uplands account for about 80% of the total arable land.

The bush fallow system is a very common farming practice on the uplands of Sierra Leone although it is also practiced in almost all agroeclogies. Upland rice farming system involves inter cropping rice with a variety of other crops such as cassava, maize, sorghum,sesame, pigeon pea, okra, garden egg, and other leafy vegetables. Rice normally occupies about 50% of the cropland. The limitation of this system as a sustainable farming practice is the increasing decline in the fallow period. Generally, the length of fallow period is reported to differ across the country with a mean of 8.8 years . In recent times, it is reported that the fallow period has dropped from the recommended period of ten or more years to about 5 years in rural areas and 3 – 4 years along major highways .Apart from the FAO/UNDP survey in 1979 which estimated an average fallow period of 8.8, there has been very little work done to update information on length of fallow period in different parts of the country. There is lack of information on the current extent of reduction in fallow period in different parts of the country particularly in the eastern region of Sierra Leone which is home to the remaining rainforest of the country.

The continued decline in the fallow period is a major threat to the persistence of the rain forest in the eastern region of Sierra Leone as farmers are tempted to slash-and burn the remaining forest for upland rice farming. An understanding of the extent of reduction in fallow period in the Eastern Region of Sierra Leone will throw light on the magnitude of the problem and inform policy makers and land use planners to enable them develop intervention strategies to counteract the negative impact of the practice.This study was therefore conducted to determine: 1) the extent of reduction of the fallow period in the Nongowa Chiefdom of Kenema District; 2) the causes of reduction in the fallow period; 3) farmers’ perception of the relevance of fallow period and the implications of reduction of fallow period on crop production. Sierra Leone is divided into four administrative blocks: the Provinces, the Districts, the Chiefdoms, and the Sections in decreasing sizes and administrative authority respectively.