Soil Colour as a Pedo-Transfer Function of Soil Organic Carbon and Fertility in a Typic Plinthaqualf

Abstract

The need to guide the land users on the appropriate usage of land and fertility maintenance is very imperative in addressing food sufficiency. Thus, a study was conducted to investigate the erroneous belief by local farmers' that soil colour can effectively predict soil productivity. Three land use types namely: arable cropping (land use 1), oil palm (land use 2), and secondary forest (land use 3) were studied. Profile pits (3 per land use type) were dug at the three predominant land types encountered on the site viz: crest, middle slope, and valley bottom. Soil colour (moist and dry) was determined using the munsell colour chart. The results revealed that pedons at the crest and middle slope are more reddish to brownish while that of valley bottom are greyish. This changes with depth across the soil profiles. The hue varies with land use type, with land use 1 having higher hue at the valley bottom than other land use types. While this decreases as the slope increases in land use 1, the reverse was the trend in oil palm site. However, in land use 3, the hue was generally low at the valley bottom and not as high as in land use 1.