Soil Quality under Different Topo-sequences and Land Uses and Its Implication to Agriculture: the case of Choke Agroecosystem, Upper Blue Nile Basin, Ethiopia
No Thumbnail Available
Date
2023-07-20
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Understanding the diversity of soil quality across topographic situations and various land uses is essential to enhancing land management mainly soil fertility, productivity, environmental sustainability, and sustainable agriculture. This study investigates soil quality under different topo-sequences, land uses, and its implication for agriculture: the Choke agroecosystem, upper Blue Nile Basin, Ethiopia. The data were collected from both soil and socioeconomic survey from the five agroecosystems (AESs), including lowland and valley fragmented (AES 1), midland plain dominated by black soil (AES 2), midland plain with brown soil (AES 3), sloppy midland land (AES 4), and hilly and mountainous highlands (AES 5) of the Choke watershed. Forty-seven composite soil samples were collected from 0-20 cm depth from the various topo-sequences (upper, middle, and lower) and different land use types (cultivated land - CL, grazing land - GL, plantation forest land - PFL, and natural forest land - NFL). Principal component analysis (PCA), analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), and soil quality index (SQI) was used for the analysis of the soil quality. The result of the study revealed that, among the fifteen soil quality properties measured, ten, including silt, exchangeable bases, cation exchange capacity, percent base saturation, pH, organic matter, total nitrogen, and available phosphorous, were found statistically significant (P NFL > PFL > CL. Compared with NFL, the SQI of PFL and CL were reduced by 10% and 19.7%, respectively, whereas the SQI of GL was increased by 1.8%. Among AESs of Choke, SQI of GL was higher in the midland plain, dominated by Vertisol (AES 2), followed by the midland plain with Nitosols (AES 3). SQI of CL was intermediate, and SQI of GL, NFL, and PFL was good. AES 2 of the watershed recorded the highest total SQI value, whereas hilly and mountainous highlands (AES 5) recorded the lowest SQI compared to other AESs. Simple descriptive statistics show a relationship between scientific soil quality assessments and indicators used by farmers to describe their farm fields. Farmers from the midland part of the watershed perceived a high soil quality with high crop yield with green leaf color, black/dark soil color with good water holding capacity. However, higher nutrients, including soil organic matter, total nitrogen, and available phosphorous recorded in the sloppy and mountainous highlands of the watershed. This shows that there is some inconsistency in the classification of soil quality of agricultural lands by farmers and scientific assessment across the various agroecosystems, which was created by the application of soil and crop management practice. Thus, the xviii result suggested site-specific development of local knowledge on soil considering topo-sequences and land use type to improve agricultural productivity, land management practice and ease the constraints of each soil in each agroecosystem.
Description
Keywords
Soil quality indicators, topo-sequences, land use type, soil quality index, MANOVA, farmers' perception, agroecosystem, Choke watershed, Ethiopia