Discriminant functions for classifying erosion degraded lands at Otamiri, Southeastern Nigeria

Date

2002

Journal Title

Journal ISSN

Volume Title

Publisher

U. P.

Abstract

This study was conducted to evaluate the effect of natural in-situ erosion on soil physico-chemical properties and to identify indicator variables associated with various degrees of erosion on a Southern Nigeria Ultisol. A preliminary survey conducted in 1997 had delineated four erosion phases on a contiguous sloping land within a watershed The erosion classes were Non-eroded (NE), Slight (S), Moderate (M) and Severely eroded (Sv) based primarily on Ap horizon thickness. Field experiments and laboratory analysis were done in/998/99. Definite consistent relationships that were statistically significant were observed between erosion class and some soil physical and chemical properties of surface 0–10 cm layer: Among these were silt/clay ratio which ranged from 0.29 in NE to 0.19 in Sv; fine sand/coarse sand ratio were 0.33 (NE), 0.31 (S), 0.17 (M) and 0.19 (SV). Soil organic carbon (SOC) declined from 1.01% in NE to 0.60% in Sw, and (Ca+ Mg)/(Al+ H) ratio, used to infer nutrient imbalance, also decline from 1.23 in ME to 0.43 in Sv. Aluminum saturation percentage increased from 33% in NE to 60% in Sw, and Ca/Mg ratio from I. 14 (NE) to 1.62 (Sv). Pedo transfer functions suggested that erosion–induced soil alterations are more process based than simple factor dependent. It is therefore recommended that in this environment the prediction of erosion hazard and the identification of erosion classes be based on discriminant analysis derived from silt/clay, fine sand/coarse sand, Ca/Mg, and (Ca+ Mg)/(Al+ H) ratios. Soil organic carbon and Al""" saturation are equally important indicator variables.

Description

This article contain tables

Keywords

Erosion, degradation, functions, classification, Department of Soil Science Technology, pedotransfer function

Citation

Oti, N. N. (2002). Discriminant functions for classifying erosion degraded lands at Otamiri, Southeastern Nigeria. Agro-Science, 3(1), 34 - 40

DOI