Abstract:
Soil fertility loss is a major global issue, especially in developing countries, including Ethiopia.
This is a significant concern for sustainable agriculture, threatening food security and ecosystem
health. To minimize soil quality loss and protect ecosystem health, The Ethiopian government
implemented land management practices, such as soil and water conservation, area exclosure, and
planting highland bamboo (Oldeania/Yushania Alpina), to protect steep slopes, prevent soil
erosion, and generate income in the Dembecha district. However, there is insufficient research on
how bamboo forests and area exclosure affect soil quality indicators in the northwestern highland
of Ethiopia. Therefore, this study is conducted to evaluate the effects of bamboo forests on soil
quality indicators and to evaluate the effectiveness of land management practices (area exclosure
for grazing land and bamboo forest, and integrated soil and water conservation practice for
cultivated land) on soil fertility in the Gerda watershed, Northwestern Ethiopia. Soil samples were
collected from treated and untreated sites of cropland, grazing land, and bamboo forest in the
upper and lower slope positions. The collected data were analyzed following standard statistical
procedures concerning treatment, land use type, and slope position by using SPSS software. Land
management practice, land use types, and topography significantly (P < 0.05 to P < 0.001)
influence almost all physicochemical soil quality indicators. Higher clay (36.6%), pH (6.77),
organic matter (11.46%), total N (0.39 %), available P (9.25 ppm), CEC (45.38 Cmol (+) kg
)
were obtained from the treated bamboo forest at a lower slope. Relatively higher bulk density (1.36
g/cm3) and sand content (54.33) were recorded from untreated cultivated land at the upper slope.
This result implies that highly deteriorated soil quality indicators obtained from untreated
cultivated land at the upper slope might be due to improper and intensive cultivation on steep
slopes, and the application of inorganic fertilizer for a long period like urea, which leads to the
removal of the fertile soil part. Generally, this result indicated that soil degradation can be
minimized through enhancing land management practices like area exclosure, and integrated soil
and water conservation practices to make sustainable agriculture in the watershed.
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