Intensity of farmland cultivated and soil bulk density in different physiographic units in Nyakach district

A number of scholars agree that frequent cultivation raises soil bulk density through compaction and destruction of soil structure. However, no research has been conducted to establish how the intensity of farmland cultivated varies with soil bulk density in different physiographic units. High soil bulk density lowers root penetration and seed germination and therefore can be used as a measure of land degradation. Likewise the intensity of farmland cultivated can be used to measure agricultural land use intensity. This study focused on establishing the effect of physiographic units on the relationship between the intensity of farmland cultivated and soil bulk density in Nyakach District of Kenya. Physiographic units considered comprised of Plateau, Scarp Slopes, Plains and Valley Bottoms. A cross-sectional research design involving the use of purposive and simple random sampling was adopted. Structured questionnaire was used to interview 384out of the 29,214farmsteads. Soil samples were collected for laboratory analysis of soil bulk density. Correlation and regression analyses were employed in the assessment of the nature and strength of the relationship between the intensity of farmland cultivated and soil bulk density in different physiographic units. Statistically significant relationships between the intensity of farmland cultivated and soil bulk density were found in the Plateau (r = -0.267), the Scarp Slopes (r = -0.279), and the Valley Bottoms (r = -0.286) at 0.01 level of confidence. The results for the Plains showed that the relationship was statistically insignificant (r = -0.235). The study concluded that physiographic units have a significant influence on the relationships between the intensity of farmland cultivated and soil bulk density.