Contribution of Sustainable Land Management Practices to soil organic carbon Sequestration in yesir water shed, Bure Zuria Woreda, Ethiopia
No Thumbnail Available
Date
2023-08-01
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The sustainable land management program (SLMP) of Ethiopia aims to improve livelihoods and create resilient communities and landscape to climate change. Soil organic carbon (SOC) sequestration is one of the key co-benefits of the SLMP. Thus, understanding a change in different land management measures and improved agronomic practices with its relation in Carbon stock change is crucial to understand the potential of different SLM practice i.e., soil bund, pastureland management, afforestation/reforestation, and area closures will create resilient landscape to climate change.The objective of the study was to assess the impact ofSLM practice on SOC in Yesir watershed, Bure zuria District, NW Ethiopia. A total of 98 soil samples werecollected in 2010and the same number of samples collected fromthesamelocation in 2018. The study followed both qualitative and quantitative method of analysis to assess the SOC change between the two years. The study conducted on three land use types, i.e., Cultivated land, Grassland and Shrub-land. In addition, two Agro-ecological zones, i.e., Highland (above 2300m asl and Mid-highland (between 1500-2300m) were considered in the study area. The resulthighlighted that when measuring the spatial SOC stbetween thetwo AEZ in thestudyarea, more SOC quantity was observed in the Highland as compared to the Mid-highland up to 0- 20cm depth. The differences were not statistically significant, however, as demonstrated by the test of 95% of confidence interval of one way ANOV that did not provide significant differences between the two AEZs. The observed higher SOC values in the highland than in the mid altitude might be due to two factors: i)SOC density may increase in the highlands with increased precipitationasincreasedrainfallenhancesabovegroundbiomassproductionandii)decreases with temperature along increases in altitude lead to occurrence of cold soil temperature which may reduce soil carbon losses via microbial decomposition of soil organic matter. Furthermore, statistical evidence for the paired observations between the baseline and post SLM in the farmland and Grassland highlighted that there was no significant difference observed from zero. This might be due to the fact that the specific SLM technologies (“bunds with vegetations”) implemented in the agricultural land were not supported by interventions that supplies different carbon input to the soil (crop residue input and other soil management practices). Under agricultural land, factorsuch as the quantityandqualityof organic matter input, decomposition rate, and land management practices would largely determine its C sequestration potential (Bayer et al., 2006; Cochran et al., 2010). On the other hand, the study showed that, there was significant differences in the shrub-land between the two years in SOC (P<0.005) upto 20cm depth. Similarly, statistically significant variation (P < 0.05) of SOC was observed between the two years at watershed level. The observed differences could be attributed to different factors i.e., the combination of physical and biological interventions (terraces + vegetations + area enclosure) that resulted in the highest SOC. The study identified that implementation of SLM interventions can bring significant difference in terms of change in soil Organic carbon. To increase SOC stock in the agricultural land, two possible measures can be suggested, these are integration of reducedtillage ,Soilfertility management combinedwith bio-physicalinterventionsthatincreasecarboninputintothesoil.secondly,increasequality of Soil and water conservation structures and regular maintenance in the farmland.
Keywords:Watershed,Soilorganiccarbonstock, Soilorganiccarbonstock change
Description
Keywords
Watershed, Soilorganiccarbonstock, Soilorganiccarbonstock change