The effects of different grazing intensities on soil properties in Miombo Woodlands of Tanzania
Loading...
Date
2024-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agriculture
Abstract
This study was conducted at Miombo woodlands in Tanzania to
enhance the sustainability of miombo woodlands in response to the
increasing grazing pressure in miombo woodlands, driven by
agricultural expansion, population growth, and rising demand for
livestock products, has led to soil degradation, land scarcity, and
socio-economic conflicts among land users. The study aimed to
evaluate dynamics of selected soil physical and Soil organic carbon
under different grazing intensities for sustainability of Miombo
woodlands. The research used a purposive sampling and random
sampling design. Grazing intensity was evaluated through two
approaches: livestock stocking rates based on official records and a
scoring method derived from field observations. Soil organic carbon
(SOC) content was determined from topsoil samples collected from
188 plots whereas soil hydraulic conductivity (Kfs) and underground
Water movement was estimated in 117 of these plots. Statistical
analysis was carried out using R® software version 4.4.2, using
Linear Mixed-Effects Models (LMM) and Gamma Generalized Linear
Mixed-Effects Models (GLMM) with a random intercept. The results
showed a slight agreement (k=0.14) between the stocking rate and
scoring methods on classification of grazing intensities. Significant
positive effects of increasing grazing intensity GI were observed on
bulk density (BD) and preferential flow (P<0.001), while significant
negative effects (P<0.001) were observed on SOC, (Kfs), percentage
dye cover, and uniform infiltration flow. The mean SOC ranged from
2.38 ± 0.84% under light grazing intensity to 1.42 ± 0.75% under high
grazing intensity. Kfs showed a mean range of 100.08-± 65.56
mmhr-1 under light grazing intensity to 27.28 ± 22.99 mmhr-1 under
high grazing intensity, while BD ranged from 1.64 ± 0.12 gcm-3
under high grazing intensity to 1.34 ± 0.17 g cm-3 under light grazing
intensity. The study recommends developing and implementing
proper sustainable livestock management practices made to the
specific conditions of Miombo ecosystems. Adhering to sustainable
Description
MSc Dissertation
Keywords
Grazing, preferential flow, soil organic carbon, uniform infiltration depth