Journal of Science and Sustainable Development (JSSD), 2014, 1(3) 15-30 Copyright © Ambo University ISSN: 2304-2702 (print); 2414-4479 (online) DOI: https://doi.org/10.20372/au.jssd.2.1.2014.023 Impact of Land Use Types on Soil Degradation in Meja Watershed, Jeldu District, West Shoa, Ethiopia

Birhanu Ayana1, Tesfaye Balemi2 and P. Natarajan3

1Department of Biology, Shenen Preparatory School, Jibat woreda, West Shoa Zone, Oromia Region, Ethiopia 2Department of Biology, Ambo University, P.O.Box 19, Ambo, Ethiopia, E-mail: [email protected] 3Department of Plant Science and Horticulture, College of Agriculture and Veterinary Science, Ambo University P.O.Box 19, Ambo, Ethiopia

Abstract

Poor land resources management with the consequence of soil degradation is the main cause of low agricultural productivity and food insecurity in the rural highlands of Ethiopia. The current study was undertaken at Meja watershed, located in the Jeldu district, Oromia region. The aim of the study was to assess the impacts of different land use types on soil quality parameters in the watershed. Soil samples collected from the upper 0-20 cm depth from cultivated, grazing and forest lands was analyzed for various soil quality parameters. The results indicated that soil parameters such as, cation exchange capacity (CEC) and organic matter (OM) content were significantly higher for forest and grazing land than for cultivated land whereas electrical conductivity (EC), total nitrogen (TN), available phosphorus (AvP), exchangeable K, Ca and Mg contents were significantly higher for forest land compared to both grazing and cultivated lands. Other soil parameter such BD was higher for cultivated land than for the other land use types. The results clearly indicated that land use types significantly influenced soil quality suggesting that a change from forest land to the other land use types aggravated soil degradation resulting in soil fertility decline in the study watershed.

Key Words: cultivated land, grazing land, Forest/plantation land, soil quality, soil degradation index

Introduction Ethiopia, where agriculture is the backbone of the economy, severe food insecurity and natural resource Improper land use is being observed degradation have been a challenge to as a result of the challenges to increase the livelihood of many rural food production to meet the demand communities. The causes of land of increased population potentially degradation in Ethiopia could be resulting in land degradation. Land attributed to the cultivation of steepy degradation in turn has severe lands, fragile nature of soils with negative impact on agronomic inadequate soil conservation practices productivity of crops, environmental or vegetation cover, erratic and quality and on food security and erosive rainfall patterns, declining use overall livelihood of human beings of fallow system, limited nutrient (Omotayo and Chukwuka, 2009). In Birhanu Ayana et al. [2] recycling from manures and crop be implemented. It is assumed that residues, limited application of awareness creation on the extent of external sources of plant nutrients, land degradation among the farmers, deforestation and overgrazing (Belay, policy makers and other stakeholders 2003; Hurni, 1988). would help easy adoption of research recommendations and any decisions It has been estimated that 2 million ha made by policy makers to safeguard of Ethiopia’s highlands have been soil from further degradation. Thus, degraded beyond rehabilitation, and there is a need to investigate the an additional 14 million ha are relationship between land use types severely degraded (UNEP, 2002). The and soil quality to further influence removal of vegetation cover exposes farmers in their decision to choose the soil to wind and water erosion. appropriate land resource Soil compaction occurs in areas where management strategy in Meja there is excessive trampling by Watershed. The objective of the animals. In cultivated areas soil present study was, therefore, to fertility is declining as a result of the investigate the impacts of different exhaustion of soils by mono-specific land use types on soil quality based cropping and reduction of fallow on selected physico-chemical periods (UNEP, 2002). Although there properties of soil. is an overall understanding that soils of the study area are being degraded, the extent and magnitude of the Materials and Methods degradation is, however not known. This necessitated an investigation of Description of the Study Area the extent of soil degradation in terms The study was conducted at Meja of soil fertility under different land watershed, Jeldu district, West Shewa use systems. A decline in soil fertility Zone of Oromiya Regional State, induced by change in land use system Central Ethiopia (9° 02' 47" to 9° 15' was observed in many parts of the 00" N and 38° 05' 00" to 38° 12' 16" E). world (Mulumba, 2004; Ayoubi et al., The district has an undulating terrain 2011; Aghasi et al., 2011). Such decline with altitude ranging from 2,900-3,200 in soil fertility was mainly attributed meters above sea level. Rainfall to loss of nutrients and organic matter pattern of the area is bimodal with the through soil erosion as a result of main rainy season from June to conversion, mainly of forestland to September and short rainy season cropland. Due to the dearth of from February to March. Mean annual detailed information on the extent of rainfall ranges from 1800 to 2200 mm. land degradation under different land The maximum and minimum use systems in Ethiopia, sound soil temperature ranges from 17 to 22OC reclamation practices and land use (District’s Agriculture and rural decisions by policy makers could not development office annual Report of Journal of Science and Sustainable Development (JSSD), 2014, 1(3) 15-30

Impact of Land Use Types on Soil Degradation in Meja Watershed, Jeldu District, West Shoa, Ethiopia [3]

2009, unpublished). The farming type, but the riverbed has a loam and system of the study area is mainly rain sandy-loam type of soil (Hurst et al., fed. The soil is clay and clay-loam 1959 cited in Dereje, 2010).

Figure 1: Map of the study location

Soil sampling and analysis homogenized and sieved through 2 Soil samples were collected from three mm sieve. A separate undisturbed soil land use types (cultivated, grazing sample for bulk density determination and forest/plantation lands) in the (BD) was collected by a core sampler watershed, to assess the status of soil (cylindrical metal sampler) from the degradation. Soil samples were taken same site. from the top soil (depth of 0-20 cm) The soil was analysed for selected soil from each land use type in a zigzag chemical properties, such as soil pH, manner using an Auger. The electrical conductivity (EC), soil composite sample from each land use organic matter content (OM), total type was separately ground into fine nitrogen (TN), available phosphorous tilth using mortar and pestle, (AvP), cation exchange capacity (CEC)

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Birhanu Ayana et al. [4] and basic exchangeable cations. Soil it to constant weight in an oven at pH and electrical conductivity of soil 1050C for 24 hours and reweighing samples were determined at 1:2.5 after cooling. Bulk density was then (soil: water suspension) using pH calculated from the measurement of meter and portable conductivity the bulk volume, using the core length meter, respectively according to Black and the diameter of the cutting edge (1965). The Walkley and Black (1934) of the sampler. wet digestion method was used to determine soil carbon content and …………(1) percent soil OM was calculated by multiplying percent soil OC by a 2 factor of 1.724 with the assumptions Volume of sample = π r h………… (2) that OM is composed of 58% carbon. Where: π = 3.14, r = radius of internal Total nitrogen was determined using diameter of the core sampling tube, Kjeldahl method according to Black h= height of core sampler (1965). Available P in soil was tube. analyzed according to the standard procedure of Olsen et al. (1954). Cation Determination of soil degradation exchange capacity (CEC) and index: the soil degradation index (DI) exchangeable bases (K, Ca and Mg) was computed by the procedure of were determined after extracting the Islam and Weil (2000) as cited in soil samples by ammonium acetate Mulugeta (2004). To compute DI, the (1N NH4OAc) at pH 7.0. difference between mean values of Exchangeable Ca and Mg in the each soil quality parameter under extracts were determined using cultivated and grazing lands, and the atomic absorption spectrophotometer, baseline values of similar soil quality while K was determined by flame parameter for forestland were photometer (Chapman, 1965; Rowell, computed and expressed as a 1994). Cation exchange capacity was percentage of the value under the estimated titrimetrically by distillation forestland. These percentage changes of ammonium that was displaced by were summed across all soil quality sodium from NaCl solution parameters to compute the cumulative (Chapman, 1965). DI value for each land use types, which was used as an overall index of Physical degradation was assessed soil degradation or improvement. using bulk density. Bulk density of F − I undisturbed soil sample was DI = ×100% (3) determined using core sampler I …………. (cylindrical metal sampler) (Blake, Where DI = Degradation index 1965) and determining the mass of solids and the water content of the core, by weighing the wet core, drying

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Impact of Land Use Types on Soil Degradation in Meja Watershed, Jeldu District, West Shoa, Ethiopia [5]

F= the mean value of soil quality lowest BD (1.58 mg m-3). The parameter for cultivated land or compaction of the top soil of the grazing land cultivated land by livestock during grazing after harvest and during I = the mean value of soil quality fallow period and intensive parameter for soil from forestland agricultural practices might be the reasons for the higher BD in the case Data analysis of cultivated land. This was in line The data obtained from the analysis of with the results of Lal (1986) who soil sample was subjected to a one- reported that the BD of soils from way analysis of variance (ANOVA) pasture and crop land, at two using SAS statistical software version sampling depths (0-10 cm and 0-20 9.2. Mean separation was done using cm), were significantly different from Tukey test at a significance level α = that of forest land, the value being 0.05. higher for crop and pasture land. Such differences might be ascribed to the

compaction of topsoil due to Results and Discussion overgrazing in the case of pasture land and the use of heavy machinery Effect of land use type on or intensive agricultural practices in soil bulk density, pH, EC and the case of crop land. The lowest BD in the current investigation in CEC forest/plantation land was most 3 Bulk density of the soil (BD; g/cm ) probably ascribed to its higher soil was significantly affected (P<0.001) by organic matter content than the other land use types. The soil samples taken land use types (Table 3) since organic from cultivated land showed matter and bulk density are significantly higher bulk density negatively correlated. Likewise, 3 (1.01g/cm ) as compared to the soil Aweto and Dikinya (2003) reported samples collected from both grazing that the lower bulk density under the and forest/plantation lands (Table 1 canopy of trees in forest land was below). However, there was no presumably due to the effect of litter significant difference in BD between addition to soil under the canopies, soils drawn from grazing land and which has resulted in organic matter forest/plantation land. Likewise, Igwe build-up in soil under the canopies (2001) reported that soils of the arable relative to level of the organic matter - land have the highest BD (1.83 mg m in the soil outside the canopies. 3) and soils of native forest land the

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Table 1: Effects of land use types on selected soil physical and chemical properties in Meja watershed

0-20cm Soil Parameters Treatments CEC Ex K Ex Mg BD EC SOM A P (cmol (cmol Ex Ca (cmol (gm/cm3) pH (µ/cm) (%) TN (%) (ppm) kg-1) kg-1) (cmol kg-1) kg-1) Cultivated land 1.01a 5.07c 86.7c 4.23b 0.35c 3.0b 39.4b 0.42b 18.01c 1.99c Grazing Land 0.87b 5.36b 102.5b 7.74a 0.42b 2.0c 45.7a 0.31c 22.06b 3.64b Forest/plantation 0.81b 6.23a 186.0a 7.76a 0.46a 5.8a 45.9a 1.51a 28.02a 6.00a land

The analysis of variance (ANOVA) for acids production, which ultimately soil pH revealed that there was a acidifies the soil. Additionally, the significant difference (p<0.001) among lowering of the pH value of this soil the land use types. The pH value of might be due to the reduction of soil soil taken from forest/plantation land OM which lowered the buffering was the highest (6.23) and that of the capacity of soil acidity. Likewise, cultivated land was the lowest (5.07) Tesema (2008) stated that the low pH (Table 1). Soil taken from in cultivated field was probably due forest/plantation land showed to continuous removal of basic cations significantly higher pH value than soil by crops, intensive cultivation and from other land use types (Table 3). washing away of exchangeable bases Similar soil pH trend was reported by by rill and sheet erosion. The Gebeyaw (2007) for the different land relatively higher pH value in use types under study in Maybar forest/plantation soil was attributed areas of south Wello zone of Ethiopia. to the presence of relatively higher According to him, the highest (6.82) total exchangeable bases and higher and the lowest (5.83) soil pH values CEC (Table 1) than in the cultivated were recorded for forest and land and also due to the highest soil cultivated lands, respectively. The OM content (Table 1). Generally, the lowest pH value of soil taken from the soils of cultivated land and grazing cultivated land in the present land were strongly acidic whereas that investigation might be due to the of forest/plantation land were slightly uptake of basic cations by the plants acidic according to the standard rating and its removal along with the of SSSA (1997). harvestable parts, intensive cultivation that enhanced leaching of Results also showed that the electrical basic cations and drainage to streams conductivity (EC, μs.cm-1) of the soils in runoff generated from accelerated was significantly influenced by land erosions. It may also be due to higher use types (p<0.001). Mean EC values organic matter decomposition in of 86.75, 102.5 and 186 were recorded cultivated land that leads to organic for cultivated, grazing and Journal of Science and Sustainable Development (JSSD), 2014, 1(3) 15-30

Impact of Land Use Types on Soil Degradation in Meja Watershed, Jeldu District, West Shoa, Ethiopia [7] forest/plantation lands, respectively recorded in the present study for (Table 1). Forest/plantation land soils taken from grazing land and showed significantly higher EC value forest/plantation land was probably when compared to both grazing and due to their higher organic matter cultivated lands whereas grazing land content compared to that of showed significantly higher EC value cultivated land. Since clay and than cultivated land (Table 1). The colloidal OM have the ability to lowest EC value for cultivated land absorb and hold positively charged might be associated with the loss of ions, the high cation exchange base forming cations (Ca++ and Mg++) capacity was expected. So, the following deforestation and intensive existence of higher OM under cultivation. Doerge (1999) attributed forest/plantation and grazing lands the difference in EC of the soil taken and their non-significance difference from different land uses types to in their soil OM content made them to difference in soil moisture contents, have a relatively higher CEC content salinity levels, temperatures and in the present study. This is in cation exchange capacities of the soil. agreement with the report of Unger (1997). According to him, the soils The Cation exchange capacity (CEC; under various types of agricultural cmol kg-1) of soils was significantly land uses contained less organic affected (p< 0.001) by land use types. matter content, total nitrogen, The mean CEC values of the soils in exchangeable bases and cation the studied watershed stand at 39.4, exchange capacity (CEC) than similar 45.7 and 45.9 for cultivated land, soils under natural vegetation. grazing land and forest/plantation Gardiner and Miller (2004) also land, respectively (Table 1). The result indicated a decrease in soil OM indicated that there was a high substantially lowers the amount of significance difference in CEC of soil CEC to the soil. Even if the mean CEC taken from forest/plantation and value of cultivated land in the present grazing land as compared to the soil study was lower than that of grazing taken from cultivated land (Table 1). and forest/plantation lands due to its Likewise, Woldeamlak and lower OM content, the figure (CEC Stroosnijder (2003) cited in Gebeyaw value) was not as such bad because of (2007), have reported that CEC value its relatively higher percentage of clay was highest in soils under forest land content than the other land use types and lowest under cultivated land. The (Table 1). A decrease in soil pH (Table lowest mean CEC observed in the 1) might be also the cause for the cultivated lands might be due to loss lowering of CEC of the soil under of basic cations (Mg and Ca) by crop cultivated land. The same finding was harvest and soil erosion. The reported by Gardiner and Miller relatively higher mean value of CEC (2004).

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Effect of land use types on soil of most OM losses. The present study OM, TN and AvP also confirmed the reports of Brown Organic matter (OM) (%) content was and Lugo (1990), Spaccini et al. (2001) significantly (P<0.001) affected by the and Wu and Tiessen (2002) who all land use types. The soil OM content observed a comparable loss of soil OM was highest (7.76%) for soil drawn and TN due to cultivation of forest from the forest/plantation land and and pasture lands. Soil OM at the lowest (4.23%) for soil taken from the depth of 0-20 cm for cultivated soils cultivated land (Table 1). The result was lower than that of forest and indicated that there was significant pasture soils by 49.5% and 47.9%, difference in soil OM content between respectively at similar soil depth. cultivated land and grazing land as Similarly, after 18 years of cultivation well as between cultivated land and of farm land, soil TN decreased by forest/plantation land. However, 51% and 47.7%, respectively there was no significant difference compared to the forest and pasture between grazing and forest/ soils. The lower carbon/OM content plantation lands (Table 1). According in cultivated soils could also be to Tan (1996) rating of organic matter, attributed to lower residue return to the soil OM content of both grazing the soil, as a significant portion of dry and forest/plantation lands of the matter production are removed in present study was very high while harvested material (Golchin et al., that of cultivated land was medium. 1995). Likewise, Mulugeta (2004) The lowest OM content for the reported that the decline in SOC and cultivated land in the present study total N, although commonly expected might be due to higher OM following deforestation and decomposition associated with conversion to farm lands, might have sufficient aeration, inadequate been exacerbated by the insufficient fertilization with manures, OM inputs of organic substrate from the removal by erosion, removal and farming system due to residue burning of crop residues. This result removal and burning on the farm agrees with the report of Roose and fields. On the other hand, the greater Barthes (2001) who reported that OM in the forest/plantation soils was periodic tillage operation with due to higher production, insufficient soil and water accumulation and decomposition of management practices in cultivated litters and low physical soil loss (Islam land may be responsible for the et al., 1999 and Descheemaeker et al., significantly lower soil organic matter 2006). Similarly, forest/plantation soil content. The report of Lewandowski had the highest soil OM because the (2002) cited in Solomon (2008) also soil was not tilled or exposed to confirmed the results of the present erosion. study. He reported that continuous cultivation becomes the major causes Journal of Science and Sustainable Development (JSSD), 2014, 1(3) 15-30

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Results also showed that total Girma (1998) who also concluded that nitrogen (TN) (%) was significantly the lower levels of organic carbon and affected by the different land use TN content in cultivated soils might types (P<0.001). The TN (%) content of have resulted from a combination of soil was 0.46%, 0.42%.and 0.35% for lower C inputs because of less soils taken from forest/plantation, biomass C return on harvested land grazing and cultivated land, and greater C losses because of respectively (Table 1). According to aggregate disruption, increased soil TN content rating by Barber aeration by tillage, crop residue (1984), the soils taken from the burning and accelerated soil erosion. forest/plantation and the grazing land The report of Mulugeta (2004) cited in in the present study fall in “very high” Gebeyaw (2007) also revealed that the and that of the cultivated land fall in levels of soil OC and TN in the surface “high” class. Soil taken from soil (0-10 cm) were significantly lower, forest/plantation land showed and declined increasingly with significantly higher TN value than soil cultivation time in farmlands, from other land use types (Table 1). compared to the soil under the natural The relatively lower TN content in the forest. Su et al. (2004) also found out current investigation for cultivated that even short-term cultivation had a land might be associated with the significant influence on soil C, N and reduction in soil OM content. This soil biological properties of soil when statement is supported by the compared to the native grasslands findings of Yeshitela and Bekele soils. (2002), who also reported that the TN content of the soil in different The result of available phosphorus communities vary with the amount of (AvP; ppm) of soils was significantly organic matter; the TN being higher in affected (p<0.001) by land use types. soils with higher organic matter The highest (5.81 ppm) and the lowest content and lower in soils having (2 ppm) AvP content of soil was lower organic matter content. observed in the soil taken from the Moreover, continuous cropping (or forest/plantation and the grazing the removal of large quantities of lands, respectively (Table 1). nutrients from the soil) without According to Tisdale et al. (1997) applying additional organic matter rating of AvP levels, the AvP of the such as manure and inorganic soils of the land use types in the fertilizer, removal/burning of crop studied watershed fall in the medium, residue, and accelerated erosion might low and very low range for also be the cause of reduced soil TN forest/plantation, cultivated and content in cultivated land. Our grazing lands, respectively. Soil taken reasoning is in agreement with reports from grazing land showed of Mullar-Harvey et al. (1985) and significantly lower AvP value than

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Birhanu Ayana et al. [10] soil from other land use types (Table phosphorous which supports our 1). The relatively lower content of present finding. AvP content in the soils taken from cultivated and grazing lands as Effect of land use types on compared to that of forest/plantation soil basic exchangeable land was probably due to plant cations (K+, Ca++and Mg++) uptake (for cultivated land) and losses Exchangeable potassium (K+; cmol kg- through soil erosions. This present 1) content in soils of the studied finding draw support from reports of watershed was significantly affected Murphy (1968) and Eylachew (1987) (P<0.001) by land use types. who both reported that the AvP under Exchangeable potassium was lowest most soils of Ethiopia declined by the (0.31) in grazing land and highest in impacts of fixation, abundant crop the forest/plantation land (1.51) harvest and soil erosion. It also agrees (Table 1). The results revealed that the with Mekuria (2005) who reported exchangeable K+ of soil taken from that the conversion of natural forest/plantation was significantly vegetation to cropland was an higher than that of both cultivated important cause of the decline in soil and grazing land (Table 1). The available phosphorous content. The relatively lower exchangeable K+ higher AvP content in the soil drawn contents in the present investigation from cultivated land as compared to in soils taken from the cultivated and that of the grazing land was probably the grazing lands compared to that of due to the application of the forest/ plantation land might be diammonium phosphate (DAP) due to its removal through harvested fertilizer by farmers. Likewise, and grazed parts of the plants from Gebeyaw (2007) reported that even the cultivated and grazing lands, though the OM content of the respectively. The application of acid cultivated land was lowest compared forming fertilizers to the cultivated to the other land use types, the higher land might be another major factor AvP content in cultivated compared for reduction of exchangeable K+ in to grazing land in the present study the cultivated soil, since H+ ion could be due to the application of competes for the K+ binding site diammonium phosphate (DAP) leading either to its leaching loss or fertilizer on the cultivated land. The favoring its uptake by the plants. This higher AvP in forest/plantation land suggestion is also in agreement with as compared to the other land use the reports of Baker et al. (1997) and types on the other hand could Wakene (2001) who reported that the probably be attributed to the application of acid forming fertilizers accumulation of litter fall to forest soil. was a major factor affecting the Silver (1994) has also found a high distribution of K+ in soil systems correlation between litter fall and soil mainly by enhancing its depletion especially in tropical soils. On the Journal of Science and Sustainable Development (JSSD), 2014, 1(3) 15-30

Impact of Land Use Types on Soil Degradation in Meja Watershed, Jeldu District, West Shoa, Ethiopia [11] other hand, the relatively higher with the findings of Dudal and exchangeable K+ content in soil taken Decaers (1993) who stated that from cultivated land compared to that continuous cultivation, application of of grazing land might be due to acid forming inorganic fertilizers, continuous cultivation which most excessive leaching as a result of high likely exposed the K rich parent rainfall, high exchangeable and materials to further weathering and extractable soil Al content and low pH subsequently the release of results in low Ca and Mg contents and exchangeable potassium. Chadwick et hence in Ca and Mg deficiencies. al. (1999) reported that weathering Similarly, Saikhe et al. (1998) stated favoured by frequent tillage, exposes that continuous cultivation and use of the fixed K of soil to further acid forming inorganic fertilizers weathering making exchangeable K+ deplete exchangeable Ca and Mg. remarkably higher in farm lands than in other land use types which Exchangeable magnesium (Mg++; cmol supports our suggestion. On the other kg-1) content was also significantly hand, the highest exchangeable K+ (P<0.001) affected by land use types. content in the soil drawn from forest/ The exchangeable magnesium content plantation land might be related to its was highest (6) in the soil drawn from high pH value (Table 1) and this the forest/plantation land and lowest finding was also in agreement with (1.99) in the soil taken from the reports of Mesfin (1996) who cultivated land (Table 1).The cause for observed high exchangeable K under the decline in exchangeable high pH tropical soils. magnesium in cultivated land was the same as that of exchangeable calcium. The exchangeable calcium (Ca++; cmol The lowest exchangeable magnesium kg-1) was significantly (P<0.001) value obtained in the cultivated land affected by land use types. The could also be related to the influence highest (28.02) and the lowest (18.01) of intensive cultivation and abundant exchangeable Ca++ contents were crop removal with harvestable parts observed in the soils taken from with little or no use of input as forest/plantation and the cultivated reported by Singh et al.(1995) and He lands, respectively (Table 1). et al. (1999). Gebeyaw (2007) has reported similar status of exchangeable Ca++ reduction Soil degradation index in cultivated land. The lower The degradation indices (DI) (%) for exchangeable Ca++ in the present selected soil properties under finding in cultivated land could be different land use types were attributed to the reduction of soil pH summarized in Table 2. and excessive leaching due to continuous cultivation. This agrees

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Table 2: Degradation indices (DI) of selected soil properties as influenced by land use types

Mean values of soil attributes for the land use types Degradation Indices (%) Forest/planta Soil Property tion land Grazing land Cultivated land Grazing land Cultivated land BD 0.81 0.88 1.01 8.64* 24.69* pH 6.22 5.36 5.07 -13.83 -18.49 SOM 7.76 7.74 4.23 -0.26 -45.49 TN 0.46 0.42 0.35 -8.70 -23.91 AvP 5 2 3 -60 -40 CEC 45.92 45.68 39.38 -0.52 -14.24 Cumulative soil degradation indices -74.67 -117.44 * The value is taken as negative

In the computation of degradation land. The major reasons for the index (Table 2), the negative value deterioration of soil attributes (both indicated deterioration of soils in chemical and physical) under terms of the typical soil property cultivated land were removal of considered. The results of nutrients through continuous computation of degradation index cropping, removal of crop residue, indicated that soil under both low levels of fertilizer application and cultivated and grazing lands showed poor soil and rainwater management deterioration in all the soil parameters practices. studied. Except with AvP, which was severely deteriorated in grazing land (-60%), the other parameters were Conclusion more severely deteriorated in the soil obtained from cultivated land than The attributes of the soils under the from grazing land. It can be observed cultivated lands showed overall that soil OM, AvP, BD and TN were change towards the direction of loss of the most deteriorated soil parameters their fertility compared to the soil with values of -45.49%, -40% , -24.69% attributes of the adjacent and -23.91%, respectively for forest/plantation and grazing land cultivated land. However, soil CEC soils. Hence, major declines were was the least deteriorated soil observed for soil pH, electrical parameter with values of -14.24% for conductivity (EC), organic matter cultivated land. Likewise, AvP and (OM), total nitrogen (TN), cation soil OM were the highest and the least exchange capacity (CEC), deteriorated soil parameters with - exchangeable Ca and exchangeable 60% and -0.26% values, respectively Mg more in cultivated land than the for grazing land. Generally, soil under other land use types. The average grazing land cumulatively values of other selected soil physico- deteriorated by -74.67 whereas it chemical properties under the deteriorated by -117.44for cultivated cultivated, grazing and forest/ Journal of Science and Sustainable Development (JSSD), 2014, 1(3) 15-30

Impact of Land Use Types on Soil Degradation in Meja Watershed, Jeldu District, West Shoa, Ethiopia [13] plantation lands showed changes in Contamination and Reclamation, EPP bulk density (1.01,0.87,and 0.81g/cm), Publications Ltd, 11 (3). AvP (3, 2 and 5.81 ppm) and Ayoubi S., Khormali F., Sahrawat K.L. & exchangeable K (29.98, 25.7 and 60.73 Rodrigues de Lima A. C. 2011. Assessing ppm) respectively for the watershed. Land Use Change on Soil Quality These variations of soil Indicators a Loessial Soil in Golestan Province, Iran J. Agr. Sci. Tech., 13: 727- physicochemical properties between 742 land use types indicate the risk to the sustainable crop production in the Baker M. R., Nys C, & Picard J. F. 1997. The area. Therefore, the expanding effects of liming and gypsum application on a sessile oak (Quercus petraea) stand at population in the study areas will Larcroix- Scaille (French Ardennes). I. have to seek strategies to secure food Site characteristics, soil chemistry and and a sustainable solution that better aerial biomass. Plant and Soil, 150, 99-108 addresses soil managements. Barber R. 1984. A reassessment of the dominant soil degradation process in The Ethiopian highlands: Their impacts and Acknowledgement hazards. 23, LUPRD, MoA, and FAO. Belay S. 2003. Integrated watershed We would like to acknowledge the management approach to sustainable Nile Basin Development Challenge of land management (Experience of SARDP in East Gojjam and South Wollo). pp.127- the CGIAR Challenge Program for 136. In: Tilahun Amede (Ed.). In: Water and Food for their financial Proceedings of the Conference on the support to undertake this piece of Natural Resource Degradation and work. We also like to thank the Environmental Concerns in the Amhara National Regional State: Impact of Food laboratory technicians working at Security, July 24-26, 2002, Bahir Dar. The Ambo University and Holeta Research Ethiopian Society of Soil Science (ESSS). Center for the assistance rendered in Addis Ababa, Ethiopia. laboratory analysis of the soil samples. Black CA. 1965. Methods of Soil Analysis. Part I and II, American Society of Agronomy. Madison, Wisconsin, USA. 1572

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