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North American Open Agriculture & Soil Science Research Journal
Vol. 1, No. 1, October 2014
Table of Contents
Articles
Authors: *I.J. Tekwa, A.B. Alhassan and F. Fali
Pages: 1 - 9
ABSTRACT:
A 2 year field study was carried out in Mubi area to assess soil loss from ephemeral gully (EG) erosion at 6 different locations (Digil, Vimtim, Muvur, Gella, Lamorde and Madanya) between April, 2008 and October, 2009. Each location consisted of three watershed sites from where data were collected during the study period. Land use and conservation practices were noted, while EG channel parameters (length, width, depth and shape) were measured at each site. Physico-chemical properties of the soils were determined in field and laboratory using prescribed procedures. Soil loss was measured and empirically predicted. Results showed that the soils were heterogeneous and lying on flat to hilly topography with few grasses, shrubs and trees. Soils were mainly sandy with considerable silt and clay contents. The exchangeable K, Ca, Na and Mg contents were low to high. The measured and empirical area of soil loss (ASL) ranged from 168.93 - 597.43 m2 and from 181.80 - 350.32 m2 respectively in 2008, while it was respectively from 70.02 - 426.78 m2 and 158.42 - 437.98 m2 in 2009. The measured volume of soil loss (VSL) ranged from 73.42 - 328.61 m3, while the empirical estimates had lower range of 86.89 - 292.33 m3, respectively in 2008. The VSL also ranged from 90.06 - 311.91 m3, and from 85.43 -346.98 m3 in respect of measured and empirical estimates in 2009. Hence, the measured mass of soil loss (MSL) was 98.78 - 446.33 kg/ac compared to a range of 112.78 - 383.72 kg/ac for empirical estimates in 2008. The MSL was 114.46 - 397.89 kg/ac and 106.82 - 447.11 kg/ac in terms of the actual and empirical erosion in 2009. The measured was generally comparable with the empirical soil loss. Both measured and empirical ASL was higher at Muvur in 2008 and lower at Lamorde and Madanya in 2008 and 2009 respectively. The empirical soil loss was slightly over or under estimated. Future researches are recommended to apply these suitable empirical models as cheaper alternative to field measurement or scarce physically based models in erosion studies in Mubi area.
Key words: Soil loss, Estimation, Measured, Empirical, Ephemeral-gully, Mubi, Northeast-Nigeria
Authors: *I. J. Tekwa, A.M. Chiroma and E.Z. Apagu
Pages: 1 - 9
ABSTRACT:
A field study was carried out in Mubi area to assess soil loss from ephemeral gully (EG) erosion at 6 different locations (Digil, Vimtim, Muvur, Gella, Lamorde and Madanya) between April, 2008 and October, 2009. Each location consisted of three watershed sites from where data were collected during the study period. Land use and conservation practices were noted, while EG channel parameters (length, width, depth and shape) were measured at each site. Physico-chemical properties of the soils were determined in field and laboratory using prescribed procedures. Soil loss was measured and empirically predicted. Results showed that the soils were heterogeneous and lying on flat to hilly topography with few grasses, shrubs and trees. Soils were mainly sandy with considerable silt and clay contents. The exchangeable K, Ca, Na and Mg contents were low to high. The empirical soil loss was generally related with the measured soil loss and its prediction was widely reliable at all sites, regardless of season. The measured and empirical soil loss were better related in terms of VSL (r2 = 0.9330) and MSL (r2 = 0.9171), than for ASL (r2 = 0.2673) predictions on aggregate basis. The empirical estimates of VSL and MSL were consistently higher at Muvur (less vegetation) and lower at Madanya and Gella (denser vegetations) in both years. The maximum efficiency (Mse) of the empirical equation in predicting ASL in the sites was between 1.4100 (Digil) and 89.0678 (Lamorde), while the Mse was higher at Madanya (2.5577) and lowest at Vimtim (15.6635) in terms of VSL prediction efficiency. The model’s efficiency (Mse) also ranged from 1.8359 (Madanya) to 15.7443 (Vimtim) in respect of MSL predictions. Recommending that soil conservationists, farmers, private and/or government agencies, should use the empirical model for erosion studies in Mubi area.
Keywords: Empirical model, Soil Loss, Prediction efficiency, Ephemeral Gully Erosion, Mubi, Northeast Nigeria