An experiment was conducted to evaluate soil structural and chemical properties of a ten years fallowed field soil following cassava-cowpea intercrop in Micheal Okpara University of Agriculture, Umudike in South Eastern Nigeria. Soil sample was randomly collected four meters apart from two depths (0-15cm and 15-30cm), and in triplicate for laboratory analysis to assess horizontal (space) and vertical (depth) variability on the selected soil properties, as well as evaluate if the fallow period had restored soil quality status by comparing observed values with established critical minimum for soil fertility indices. The soil structural and chemical properties analyzed were moisture content, aggregate stability, bulk density, total porosity, organic matter content, exchangeable acidity, exchangeable cations, percent base saturation and soil pH. Results showed that horizontal variations in soil exchangeable acidity and moisture content were statistically significant at P=0.05, while depth significantly (P=0.05) influenced the organic matter content, there was a decrease proportional to depth of sampling. Moisture content decreased with depth and significantly varied horizontally along sampling points. Generally the soil water properties (moisture content and total porosity) and organic matter were higher in the top soil than in the subsoil, while bulk density and exchangeable acidity were higher in the subsoil than in the top soil. Comparison of soil values with established critical minimum indicate that chemical properties ( organic matter and base saturation) had values that indicate the soil maintains moderate class in the range of chemical quality index while structural properties ( Ksat, AS, and TP) suggest that soil has attained the quality of the high fertility class range.

Keyword: Fallowed field, cassava cowpea intercrop, soil water properties, exchangeable acidity, bulk density, total porosity

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