Impact of Grazing Intensity on Soil Properties in Teltele Rangeland, Ethiopia

Abstract

Grazing intensity (GI) is a major determining factor that controls the functioning of rangelands and the overall nutrient cycle. The Teltele rangeland is used for communal grazing area by the local pastorals; however, to date, there is no documented study data about the impact of GI. The objective of this study was to evaluate the impacts of grazing intensity on selected soil properties in the Teltele rangeland, Ethiopia. Soil samples were collected from different GI sites using different elevation gradient and soil depth from both open grazing and bush-encroached grazing land sand-assessed soil properties. Grazing intensity, elevation, and soil depth significantly (p < 0.05) affected both soils’ physical and chemical properties but rangeland types had no significant effect. The correlation analysis of soil characteristics with the principal component analysis axes showed significant variation. The highly weighted and correlated properties under principal component 1 (PC1) were electrical conductivity, organic carbon, total nitrogen, available phosphorus, and potassium, and under principal component 2, sand and bulk density with equal loaded value (r = −0.998), clay and silt, with silt (0.962) a more loaded one. Soil pH (0.743) demonstrated a significant (p < 0.05) positive correlation with sodium (−0.960) at PC1 (r = 0.610). Based on our results, we recommend further model-based studies on spatial–temporal change of soil properties due to impact of grazing intensity, combined with GIS and remote sensing data to be developed for sustainable rangeland management.

Grazing lowers soil multifunctionality but boosts soil microbial network complexity and stability in a subtropical grassland of China

“…Some studies found that grazing promoted nutrient cycling ( Zhang et al, 2021a ) and enhanced soil net nitrogen (N) mineralization and N nitrification ( Zhou et al, 2017 ; Dong et al, 2020b ), NH 4 + ( Lai and Kumar, 2020 ), NO 3 – ( Wang et al, 2016 ) and available phosphorus (P) ( Hao and He, 2019 ), potassium (K), and calcium (Ca) ( Arevalo et al, 1998 ) and have a positive impact on the availability of soil nutrients ( Faghihinia et al, 2020 ; Xu et al, 2022 ). Other studies showed that grazing diminished the net mineralization rate ( Shan et al, 2011 ) and decreased available soil N and P ( Hao and He, 2019 ; Liu et al, 2021 ; Yu et al, 2021 ), K ( Fenetahun et al, 2021 ), Ca, and magnesium ( Binkley et al, 2003 ). Because nutrient availability has a very important effect in soil microbiome ( Fierer, 2017 ; Wang Z. et al, 2019 ; Ding et al, 2020 ), we assumed that the grazing-triggered alterations in available elements may also shift the microbial NP limitations and the attributes of soil microbiome.…”

“…These could result in a decline in the air and water permeability ( Daniel et al, 2002 ; Zhang et al, 2018b ) and soil moisture ( Hou et al, 2014 ; Li et al, 2021 ; Liu et al, 2021 ). However, grazing also increased soil pH ( Binkley et al, 2003 ; Hao and He, 2019 ; Fenetahun et al, 2021 ; Li et al, 2021 ). Since soil pH, O 2 , and water were most crucial driving forces of soil microorganisms ( Fierer, 2017 ), and grazing compressed the living niche for soil microbiome ( Chai et al, 2019 ; Proesmans et al, 2022 ) and negatively affected the growth of microbes ( Zhan et al, 2020 ), we speculated that the changes caused by grazing may have a far-reaching impact on the attributes of soil microorganisms.…”

“…A large body of field experiments and meta-analyses have been carried out to measure the influences of grazing on the soil’s physical environment, available elements, and element limitations ( Zhang et al, 2018a ; Chai et al, 2019 ; Fenetahun et al, 2021 ; Liu et al, 2022 ; Van Syoc et al, 2022 ; Wang L. et al, 2022 ). Grazing could decrease soil porosity ( Tang et al, 2019 ) and increase soil bulk density ( Binkley et al, 2003 ; Davidson et al, 2017 ; Zhang et al, 2018b ; Sun et al, 2019 ; Lai and Kumar, 2020 ; Fenetahun et al, 2021 ). These could result in a decline in the air and water permeability ( Daniel et al, 2002 ; Zhang et al, 2018b ) and soil moisture ( Hou et al, 2014 ; Li et al, 2021 ; Liu et al, 2021 ).…”

“…Although increasing numbers of studies have reported the influences of grazing on soil’s physical environment, available elements ( Fenetahun et al, 2021 ; Wang L. et al, 2022 ), and element limitations ( Liu et al, 2022 ), studies about the effects of grazing on the microbial community compositions and the microbial networks are relatively scant ( Magalí et al, 2019 ). Although evidence is mounting that dissecting the relative importance of plants and soils for the impact of the microbiome ( Ding et al, 2020 ; Chen et al, 2021 ), the linkages of soil physical environment, available elements, and element limitations with the niche width, structure, function, and network of soil microorganism remain relatively scarce, which hinders our understanding of the mechanisms by which grazing changes the soil microorganisms.…”

Carbon Stock and Change Rate under Different Grazing Management Practices in Semiarid Pastoral Ecosystem of Eastern Ethiopia

“…In open-access grazing systems, where mobile and sedentary forms of livestock husbandry coexist, rangelands are exploited by multispecies herds, and grazing can cause defoliation of plants [45,46]. In this context, livestock grazing intensity is thought to have a major impact on soil carbon storage in rangeland ecosystems [10,11,47,48]. Moreover, trampling, as one component of grazing, has negative effects as it accelerates the deterioration of vegetation, transforming standing materials into litter and incorporating litter into the soil [45].…”