Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , water- ff Sciences Discussions Earth System , Hydrology and 1,4 4 , P. van der Zaag 3 [email protected]) 1086 1085 , B. Simane erent literatures show an escalating threat of land ff , and H. H. G. Savenije1 1,4 1,4 in the upper Blue Nile ect of integrating the CT with SCS on the surface runo ff , S. Uhlenbrook erences were not statistically significant apparently due to high fertility , J. Wenninger appeared to be reduced under CT by 48 and 15 %, for wheat and tef, ff 1,2 1,4 ff ] and tef [eragrostis tef]. Farmers found CT convenient to apply between SCS. fanya juus This discussion paper is/has been under review for the journal Hydrology and Earth System Sciences (HESS). Please refer to the corresponding final paper in HESS if available. UNESCO-IHE Institute for Water Education,Civil P.O. Box Engineering 3015, Department, 2601 Addis DA Ababa Delft, Institute The of Netherlands Technology, Addis AbabaInstitute University, for Environment, Water and Development, Addis Ababa University, P.O. BoxDelft 2176, University of Technology, Faculty of Civil Engineering and Applied Geosciences, Water degradation particularly inHurni, the 1993; highlands Chuma, (Mulugeta 1993; et FAO, al., 1986). 2005; Average soil Grepperud, loss 1996; rates on croplands have they will continue this practice in the future. 1 Introduction In Ethiopia, land degradationproblems, has mainly become due oneand to of the soil the fast-growing erosion population, mostand and land important household degradation nutrient environmental food poses depletion. security. a serious Di Coupled threat with to poverty national respectively. As a result,tef, CT respectively. reduced Significantly reduced sediment water-logging yieldcompared was to by observed TT. 51 Grain behind and yields SCSalthough of 9.5 in %, the wheat CT di for and tef wheat increasedvariations and by among 35 fields and of 10 participating %, farmers. respectively, Farmers who tested CT indicated that struction of invisible subsoilsuggested barriers as using a a meansinvestigated modified to the Maresha tackle e winged these “subsoiler”logging, problems soil is as loss, crop an yield integral andtion plowing tillage part convenience. has of The been new the compared approachrainfall with SCS. area of traditional conserva- in We tillage the (TT) upper onvulgare Blue 5 Nile farmers’ (Abbay) fields river in basin. aSurface Test high runo crops were wheat [triticum Adoption of soil conservationEthiopia structures mainly (SCS) due has toing been of crop low SCS, yield in incompatibility reduction, with highSCS. the increased rainfall A tradition areas soil of new of cross erosion type plowing following of and water-logging breach- conservation behind tillage (CT) involving contour plowing and the con- Abstract Hydrol. Earth Syst. Sci. Discuss.,www.hydrol-earth-syst-sci-discuss.net/9/1085/2012/ 9, 1085–1114, 2012 doi:10.5194/hessd-9-1085-2012 © Author(s) 2012. CC Attribution 3.0 License. Published by Copernicus Publications on behalf of the European Geosciences Union. (Abbay) river basin M. Temesgen Impacts of conservation tillage onhydrological the and agronomic performance of Y. Mohamed 1 2 P.O. Box 380, Addis3 Ababa, Ethiopia Addis Ababa, Ethiopia 4 Resources Section, Stevinweg 1, P.O. Box 5048, 2600 GBReceived: Delft, 29 The August Netherlands 2011 – Accepted: 21Correspondence September to: 2011 M. – Temesgen (melesse Published: 20 January 2012 5 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ff Fanja Maresha in individual fields 1 − (Betrie et al., 2011) yr 1 1 − − cient agricultural crop production plow (MST, 2008), which is now ffi Maresha e, 1993; Herweg, 1993; Tadesse and Belay, ff 1088 1087 of sediment to neighboring countries (MoWR 1 nez, 2006; Busscher et al., 2002; Norfleet et al., ı ´ − but may reach 300 tons ha 1 as a result of plowing up and down the slope, which − ff yr 1 − (Easton et al., 2010). Poor watershed management and inap- ciently used over the same line of plowing in consecutive tillage 1 ffi − cult (Shiferaw and Holden, 1999; Tadesse and Belay, 2004). Cross- impacted downstream water users through a modified flow regime lead- ffi ff reaching the structures by introducing conservation tillage. Conservation agri- (trenches following contour lines with soil bunds at the upslope side; e.g. Makurira ff However, direct application of these practices of CA is constrained by several tech- Thus, a conservation tillage system that involves contour plowing and subsoiling has One way of tackling the problem of breakdowns of bunds is to reduce the surface Farmers often complain that the structures interfere with traditional practices of Investment in soil conservation structures is expected to lower soil erosion rates and In order to reduce soil erosion, a number of soil conservation technologies have been (e.g. Lampurlane and Cantero-Mart nical and socio-economic factorscosts such of as herbicide the (morecheaper need expensive for than than dry tractor oxen season powered poweredTherefore, animal mechanical mechanical conservation feed, tillage weed tillage), high has control amongthe been but others objectives adapted but (Temesgen, to not 2007). the necessarily local doing the conditions suggested by practices achieving ofbeen CA. developed together withavailable at a a price modified of 20USD.. Subsoiling increases infiltration by disrupting plow pans based on an integrated managementwith of external soil, inputs water (FAO, and 2008).minimum biological To resources achieve or combined this, no CA mechanical issisting based soil of on disturbance; a three growing principles: (2)rotations. crop (1) permanent or organic a soil dead cover mulch (con- of crop residues); and (3) diversified crop have to be carried out perpendicularplowing to each increases other, surface which is runo calledhas cross-plowing. Cross also beenleads demonstrated to elsewhere either (Rowland, detention 1993).breaching of of the too Increased bunds much leading surface to water runo accelerated by soil the erosion downstream. bundsruno leading to waterloggingculture or was introduced as a concept for resource-e cross-plowing, especially when theof distance the between plow bunds di plowing is short, is making practiced turning (Fig. because 1), can the not beoperations traditional e (Temesgen et ard al., plow 2008). Therefore, in any two Ethiopia, consecutive tillage called operations 2004; Hengsdijk et al., 2005). cent of soil bunds, 25planted % in of trees, the and stone 7 bunds, % 60 of % the of reserve the areasincrease hillside still grain terraces, exist yields 22 (USAID, % 2000). in of moisture2007; land stressed Herweg areas and (Makurira Ludi,has et 1999). al., been But 2010; hindered for Nyssen high becauseterlogging et rainfall of behind al., areas, reduction bunds adoption and in of incompatibilityothers grain the with (Shiferaw yield, technology and the Holden, accelerated tradition 1999; of soil Sutcli cross erosion, plowing, wa- among introduced. Soil conservationchanical) technologies and are biological generally measures.Juus classified Physical as measures physical include (me- et al., soil 2010). bunds The and Ethiopianbeginning government launched in a the massive mid-1970s. soil conservation However, by program 1990, only limited SCS survived, viz: 30 per- ing to drying up2007). of It springs is estimated during thatlands the the dry trans-boundary carry rivers season about that (Bewket1993) originate 1.3 and from billion whereas tons Ethiopian Sterk, yr the high- 2005;and Blue Musefa, 61 Nile Million tons yr alonepropriate carries farming 131 practices Million tons have yr contributed(Teferi et to al., these 2010) escalating conducted rates.and in 2005 A the alone recent Choke 84 study % Mountains of has wetlands shown has that been between converted 1986 to cultivated land. been estimated at 42 tons ha (Hurni, 1993). This, byreport far, exceeds estimates the some natural rate 50are % of seriously of soil eroded, formation. the and highlands The 4surface % FAO are runo (1986) have significantly reached a eroded, point of of which no return. 25 % Moreover, excessive 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | C, ◦ ” sea- ects of ff tef). Tef, Hordeum ” season) and 15 kiremt 1 − were selected bega reaching those ff modified subsoilers E) in the upper Blue Eragrostis 0 fanya juus 44.92 ◦ Maresha ) and tef ( N 37 0 24.85 ◦ 1090 1089 Triticum vulgare spp.), wheat ( as part of the routine soil conservation works of the local Bu- ectively disrupt the plow pan resulting in increased infiltration ff and water-logging behind SCS, soil moisture pattern, convenience ff Avena fanya juus ), engido ( The prevalent farming system in the study area is a subsistence mixed crop-livestock According to Mohar (1971) the study area is a part of the highlands that largely owe Therefore, the objective of this study is to assess the hydrological and agronomic It is hypothesized that the application of the new tillage system may improve the per- reau of Agriculture.from Two each field of segments the each 4 farmers bounded such by that they have similar slopes, which ranged between has a very low canopyfields cover. to Tef prepare has fine very seedbedsof fine and the seeds to soil that control to require weeds, erosion. which repeated increases plowing the of vulnerability 2.2 Experimental setup The experiment was laid4 out replications in (4 farmers) atreated and Randomized with 2 Complete treatments Block (CT Design and (RCBD) TT). with All experimental fields were system, typical for thepower highlands needed of for the thelivestock. country, farming where operation The livestock and main providevulgare a types the good of draught part crops cultivated ofvery in crop popular the residues in study are Ethiopia, area is fed are an to annual barley cereal ( crop (belonging to the grass family) that for the erosions andand weathering Quaternary of the periods various yieldingThe rocks in study formed situ area in formed is the composed orbasalt Mesozoic, of transported Tertiary rocks regolith residual (Termaber with soil 2) varyingdominant thickness. formation. constitute soil The the group younger is parent Termaber Heptic material Alisolssystem (Gurmu, of in 2010). FAO/UNESCO the (1990) According the to study soilthe the area soil type textural classification where class in is the the study clay loam. area is mainly Nitosols while their altitude toof the the uplift Tertiary of andareas Quaternary the of periods the Arabo-Ethiopian Blue shaped land Nile the Riversurface mass. basin outer to with part an form extremely The flood of large (trap) amount the geologicalNyssen of basalt et present lava events series poured al., highland to and 2004; land Aden BCEOM, series, 1998; respectively Pik (Gurmu, et 2010; al., 1998). Recent periods are responsible son). The driest months(Woldeamlak, are 2003). November to February (locally known as “ The experiment was carried outNile at (Abbay) Enerata River (10 basin (Fig. 1).which Enerata is is about located 300 7 kmto km North North 2610 m. of West Debre of The Markosically Addis town, study represents Ababa. area the is The “Dega” altitude characterizedof zone ranges by Ethiopia. of from sub-humid the 2380 The climatic traditional m respectively, condition mean agro-climatic as and annual classification recorded typ- system rainfall by andoccurring Debre temperature mainly Markos are in weather the 1300 station. mm months yr of The June rainfall to is September unimodal (locally known as “ of plowing between SCS, rate of soil erosion and changes2 in crop yields. Materials and methods 2.1 Study site structures. As such it willerosion, reduce as water-logging well behind as SCS, making whichno longer in it a turn more need reduces convenient for soil to cross-plowing.lower plow parts Better between of moisture the distribution SCS plot between becausewith the as there upper well enhanced is and as root along growth the is soil also profile expected with to increased increase infiltration grain coupled impacts yield. of integrating CTCT with on surface SCS. runo Specifically, the study investigates the e reported (Biazin et al.,have been 2011; found Temesgen to et(Temesgen et e al., al., 2008). 2009; McHugh et al., 2007). formance of the soil conservation structures by reducing surface runo 1996). The formation of plow pans under the traditional cultivation system has been 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 1 m frame was cone was used ◦ × area 30 ) was used for the study. 2 modified winged subsoiler erence. Farmers were en- ® ff . Farmers start with contour maresha while a 1 cm Maresha 1 30 m plots delineated inside each field − × . The iron sheets were inserted 15 cm deep 1092 1091 Fanya juus measurements were made from 5 m ff A locally adapted conservation tillage (CT) has been tested in comparison with the Five farmers were selected and trained on the concepts and field applications of balances in the lab and the weights were adjusted for a moisture content of 14 %. 2.3.3 Agronomic data Plant population, plant height,biomass biomass and and grain yield grain were yieldused taken to were from delineate measured. the 5 area places for Samples inplot sample for each collection. were plot. The mixed samples A and from 1threshed the m weighted 5 and in places in put the each in field plastic after bags. drying. The The grain grain was samples then were manually weighed using electronic was kept level while tying itwas to measured the at downstream peg. 10 cmpegs. Height interval of Then the before the rope tillage. from loserope the soil CT was ground between was again the applied tiedwas two without to measured pegs removing the at was the two every carefully point pegs removed where and by the height soil hand. of profile The changed. the rope from the undisturbed soil The speed of operation was adjustedfor to ease 2 of cm s penetration into the lower compacted layers. 2.3.2 Assessing soil profile The soil profile overa the horizontal plow line to depthspaced the was 1.6 m undisturbed assessed apart, surface bytwo were both pegs. measuring placed before In the across the and distance the upstream after peg, tillage from tillage. the direction. knot was Two A placed pegs, rope 5 cm was above the tied ground. to The the rope 2.3.1 Testing soil compaction Soil penetration resistance was measured atally randomly cultivated selected fields 15 at places Enerata. in A tradition- penetrolgger (Eijkelkamp 2.3 Field measurements structures. traditional tillage system. CT involvedbarriers contour parallel plowing, to subsoiling furrows and (Fig. leaving(Fig. 3). invisible 4), CT which employs a plow makes pan it below possible theplowing to using depth undertake Maresha of followed contour by operation subsoilingmaresha plowing the can of same while be the furrows. used disrupting along Duringfor the the the same third the lines pass, next to make subsoiling.furrow, the that furrows The hinder wider flow and CT along more systemstructures, the visible slope leaves increasing thereby invisible infiltration facilitating subsurface and slow drainage barriers, percolation parallel thus in to protecting the each the soil conservation yield than that of TT,couraged the to research make project cross would visitsperformance pay of of the their CT. di fields A and meetingdiscuss discuss was the among results held themselves of with about the farmers the experiment. after they harvested the crop to of each farmer (replication)times were before sowing made while the that same. number was All 5 for farmers tef. CT plowed in wheat addition fields to 4 supervisionplained to during and field discussed works. with thea The farmers. winged experimental Each set subsoiler. participating up farmer They wasout was were first provided the with ex- advised season. to Allthemselves. other keep inputs notes An such of agreement as what was fertilizer they made and observe seeds with through- were farmers provided such by that farmers if a CT plot gave lower runo segment (Fig. 2). Thelower side three was sides bounded were bywhile the fenced remaining with 10 galvanized cm iron abovemediately the sheets after surface. while sowing. Delineation the The of dates the and plots number was of carried tillage operations out in im- both treatments 9 and 11 %. Since the field segments do not have the same dimension and shape, 5 5 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | cient ffi coe . Thus, the ff ff until it is full. Once it ff ) were installed at 10 and 30 cm depths in , which is equivalent to a 10 yr daily rainfall ff ® 1094 1093 trough was determined by measuring the depth ff is spilled through 20 pipes welded at the top of the of runo 1 ff − d 3 and daily volumetric soil moisture were analyzed using time ff ff plot, the largest plot size in this experiment. to the second main compartment, which again spills through 10 pipes 2 ff as recorded in Debre Markos weather station) with a 50 % runo 1 − measuring troughs (Fig. 7) were designed, fabricated and installed at the lower 05). Data from only 2 replications were analyzed using simple descriptive statis- . ff 0 = α Field tests carried outvealing in the the formation of Choke plow Mountains pans.the indicate Figure profile significant 6 shows of soil penetration compaction cultivated resistanceident values re- soils along below at 10 Enerata. cm reachingfor A shallow its sharp tillage. maximum rise Plow at pan inwhere about formation penetration under 20 in resistance cm, maresha Ethiopia is cultivation which has with ev- Temesgen is been et its a found al., else- typical 2008). peak plow located pan at a depth of 18–20 cm (Biazin et al., 2010; 3 Results and discussion 3.1 Plow pans 2.4 Data analysis Statistical analyses were2007). made using Hence,the mean the traditional comparisons and SPSS conservation of tillage version( the techniques 15.0 using biomass the for independent and sampletics. Windows grain t Daily test yields (Julie, surface were runo series made analysis and on descriptive statistics. An automatic meteorological stationequipment recorded was rainfall, installed temperature, nearery relative the humidity 5 and min. experimental sunshine plots.measurement duration A of ev- The rainfall. manual raingauge was installed near the experimental plots for daily 2.3.7 Meteorological data erosion while reduced height shows deposition. 2.3.6 Soil erosion Sediment yield was determinedvolume of bed as load the trapped in sumof the runo deposited of soil bed at loadon four samples corners and collected of from suspended the the load. secondthe trough. and stored third Suspended water. The compartments, load Soil after was losspegs thoroughly estimated within mixing installed the based at plot randomly was selected determined by points measuring in the each heights plot. of Increased peg height shows excess runo out of which one istrough extended can to handle sample up 10 % to(85 of mm 18 the d m remaining excess runo from a 400 m 2.3.5 Surface runo Runo corners of 4 plotsmain (two compartments. with tef andreaches The two its first with capacity excess part wheat). runo lower retains The side trough of the is the whole compartment. divided runo into One three of the 20 pipes is extended to deliver 5 % of the Soil moisture contents were continuously monitoredsors in (10HS both soil TT moisture andeach sensors, CT. plot. Moisture CaTec sen- Measurementsparts were of made each plot on bounded soil by moisture two consecutive in SCS the in CT root as zone well in as TT. the lower 2.3.4 Soil moisture 5 5 20 15 10 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ff . The in CT, ff and soil ff ff erentiated ff in TT and CT, respectively. and increasing infiltration for 1 ects of water-logging. − ff ff erence, and believe that higher ff is initiated at the bottom. This also ff occurred for TT compared to CT, and that ff 1096 1095 as a result of subsoiling, while Gebreegziab- ff in TT and CT, respectively. In tef the surface runo 1 − between CT and TT are larger for wheat than for tef (Ta- ff was 48 % in the wheat plot due to the application of CT, with for CT and TT are shown in Fig. 9, for two crops wheat and ff ff ff ect of subsoiling, contour plowing and the presence of invisible barriers. ff erences between the two is more in the wheat plot than in tef. The average ff . This result is in agreement with other investigations in similar environments: Jin ff erences in surface runo A combination of hydrological processes caused reduction of surface runo Unlike the upper layers CT results in higher soil moisture at 30 cm depth, i.e. below ff di ble 1). This is because farmers let animals trample on tef seedbed during sowing for including the e Subsoiling disrupts the plow pan therebyinvisible enhancing infiltration, barriers the contour prevents plowing water with runo movement along the slopeet thereby al. reducing (2008); surface Sojkasignificant et reduction al. in (1993);her surface Harris et runo et al. al. (2009) (1993) reported and benefits Trouse of (1983) contour all plowing reported in reducing surface runo Results of surface runo tef. As canthe be di seen, more surfacereduction of runo surface runo daily averages of 4.8 and 2.5 mmreduction d was 15 % with an average of 4.5 and 3.8 mm d roots growing deeperrecharges than groundwater. 30 cm. Farmerssoil too moisture Further noticed retention the deep inbiomass di the percolation production deeper is (see layers Sect. also of 3.8).growth CT Field desirable in is observations as CT have one than also it of in revealed deeper the TT root that reasons could for have3.4 the contributed higher to increased Surface grain yields. runo would be less in TT than in CT leadingthe to the plow negative pan e (Fig.shows deeper 8b). infiltration in Thedepths CT high than in temporal in case variation TT, there thus in making is soil more a moisture water dry at available at 30 spell. cm lower depth This would also make more water available to from standing water at the lower side of the plot. As a result, the air filled pore space CT compared to TT. The sharpof peaks the in CT time. show that it The remained pore unsaturated for spaces most in TT were probably clogged by settling fine particles ment period is short, the34.7 sample % results vol.) clearly reveal is that consistentlywhile soil higher the moisture than in reverse TT that holds (average spectively) of true (Fig. CT 8) at (average . 30 31 cm % ThisCT implies vol.) depth compared a (33.4 at reduced to and 10 surface TT. cm runo 31.4surements Average depth % values (Fig. vol., aggregate 8a in large and CTas variability b). the and of Higher soil soil TT, temporal re- moisture responds variationsdrainage. mea- to in This rainfall CT indicates events signifies better with better aeration a as drainage larger rise pore in spaces soil were moisture occupied by followed air by in quicker erosion and facilitates deep percolation of soil moisture. 3.3 Soil moisture The soil moisture measurementseach had plot, for been a taken period continuously of at one the month lower only sides (due to of vandalism). Although the measure- by a sharp line,are which laid led along to theshallow accelerated slope. layer flow becomes quickly Since in saturated the TTcauses and soil runo landslides preferentially below depending in on the thetrubed the plow furrows slope soil depth that of serves is the as lessare land, slip permeable, and made surface. the the along less However, the after(Fig. permeable contour 7) applying undis- resulting that CT in narrow slow the2007; deep down Tromp-van fill Meerveld trenches the and and McDonnell, spill movement 2006). flow of This process water reduces (Spaaks surface along et runo the al., 2009; slope Lehmann et al., Figure 7 shows the undisturbedarea soil shaded in profiles light before brown and isundisturbed after the layer. plowed conservation layer tillage. while The the The averageing dark distance brown up area between and represents the down the the furrows slope is in about TT 20 resulted cm. in Plow- straight horizontal soil layer di 3.2 Soil profile 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | er- ff fanya could ff thereby ff ects in the ff erent farmers’ fields. plow is the main rea- ff 05) (Table 2). This is due . 0 = under CT and TT, respectively. α maresha in CT led to reduced soil erosion. ff ects. Unfortunately, surface runo . Moreover, disrupted plow pans in CT ff fanya juus 1098 1097 . Measurements could only be made after sow- ff fanya juus erences in biomass and grain yield. According to ff ects could be significant before the sowing of tef (before ff fanya juus erences in soil loss due to tillage treatments. The di ff erences could be observed before sowing and hence future that reach ff ff erences are not statistically significant ( ff . During field interviews with farmers, those who practiced CT unanimously . plow. This makes it possible to control weeds between consecutive furrows , because the wings cut the soil on the sides of the V-shaped furrow created by the logged strips behind SCS inproduction TT in (Fig. the 9b), former. which could contribute to increased biomass Participating farmers noted thethe di interviews, farmers believe the reasonsweed could control, be (3) (1) extended reduced period soil ofFarmers erosion, soil believe (2) wetness, better that and (4) reduced reducedwhile soil water retention logging erosion of in in soil CT. moisturequently, CT farmers in led harvested deeper to CT layers reduced extended plots,They the on loss believe growing average, of this period. one soil resulted weekand Conse- nutrients in after hence harvesting more better TT aeration biomass plots. in and CT grain made yield. the crop Reduced greener water-logging (Fig. 9a) compared to water- 3.8 Agronomy Both biomass and grain yieldwheat were and tef, consistently with higher 35 inalthough and CT the 28 di than % increment in in TTto grain in high yield both of variation crops, wheat in and tef, soil respectively, fertility as replications were made in di consecutive tillage operations alongjuus the same line,maresha in this case, parallelby plowing to only the in one directionfanya thereby juus making it convenient toreported plow in that the the presence new of fanya tillage juus system is more convenient than TT in fields treated with One of the main problemsis associated the with inconvenience the created adoption tohave of the shown SCS tradition that by of farmers the crossson in V-shaped plowing. Ethiopia for furrow Temesgen traditional created et cross al. by (2008) plowing. the The winged subsoiler allows farmers to undertake 3.7 Convenience in plowing between SCS Other investigators (Kin et al.,Farmers 2008; too Sojka noticed et theences al., di between 1993) CT have and reported TTcompaction are similar carried larger results. out for wheat during than sowingsame for of tef. way tef This as which is undermined it causeding. treatment did by e seedbed Larger to treatment surface di research runo should include monitoring soil loss before sowing. 3.6 Sediment yield Results of sediment yieldTable observations 1. (both The suspended and resultsto bed demonstrate the load) reduced application are sediment of shown yield in CT. in Reduced both surface wheat runo and tef due 3.5 Water-logging behind Figure 10a and b showThe wheat wheat crops crop behind underder CT TT showed turned vigorous yellow growthreducing with and surface stunted greener runo growth. standapparently while CT facilitated that resulted better drainage un- in thus less avoiding surface water-logging behind runo bunds. seeded crop (Teklu and Gezahegn, 2003).infiltration, As and a thus result, undermining the treatmentonly compacted e surface be reduces monitored onlyfore after sowing, sowing. since treatment Future e moistureseedbed measurements compaction). should start be- better seed-soil contact, which is crucial for germination and establishment of the small 5 5 25 15 20 10 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , from ff with the ff ect of Long- ff 05), apparently due to . 0 = α modelling using artificial neural ff ect on stream flow in the Chemoga http://www.fao.org/ag/ca/index.html ff leading to a reduction in soil loss. Water- ff 1100 1099 , 2011. The study has been carried out as a project within a larger research pro- ects of plough pan development on surface hydrology and on soil physical erences were not statistically significant ( ff ff Environmental Economics and Management, 30, 18–33, 1996. 2008. J.: Contour furrows for inTill. situ soil Res. and 103, water 257–264, conservation, 2009. Tigray, Northern Ethiopia, Soil and Agriculture Organization (FAO), Rome, 2008. term maresha ploughing onTill. soil Res., physical 111, properties 115–122, in 2011. the central rift valleydeep of tillage Ethiopia, as Soil a function of subsequent cumulative rainfall, Soil Till. Res., 68, 49–57, 2002. lection, Site Investigation Surveyume and III Analysis, (Part Section 2and Hydrology), II, land Volume Volume IV use), I (Part Volume (PartEthiopia, 3 IX 1 1997, Hydrogeology), (Part 1998. Geology), Volume 2 X Vol- Semi-detailed (Part soil 3 survey), Land cover Ministry of Water Resources, doi:10.5194/hess-15-807-2011 watershed, Blue Nile basin, Ethiopia, Hydrol. Process., 19, 445–458, 2005. Palmieri, F.: E properties in Southeastern Brazilian plateau, J. Hydrol., 393, 94–104,modelling 2010. in the Blue Nile Basin using SWAT model, Hydrol. Earth Syst. Sci., 15, 807–818, networks technique: a2005. Blue Nile catchment case study, Hydrol. Process., 20, 1201–1216, Further research needs to be undertaken to expand the data series spatially as well Gurmu, M. G.: Groundwater Recharge Estimation and Base Flow Analysis for the Mesoscale Grepperud, S.: Population pressure and land degradation: The case of Ethiopia, Journal of Gebreegziabher, T., Nyssen, J., Govaerts, B., Getnet, F., Behailu, M., Haile, M., and Deckers, FAO Conservation Agriculture, 2008-07-08, available at: FAO (1986) Ethiopian highlands reclamation study, Final Report (Volume I and II), Food and Busscher, W. J., Bauer, P. J., and Frederick, J. R.: Recompaction of a coastal loamy sand after Biazin, B., Stroosnijder, L., Temesgen, M., Abdulkadir, A., and Sterk, G.: The e BCEOM. Abbay River Basin Integrated Development Master Plan Project, Phase 2: Data Col- Bewket W. and Sterk, G.: Dynamics in land cover and its e Betrie, G. D., Mohamed, Y. A., van Griensven, A., and Srinivasan, R.: Sediment management Bertolino, A. V. F. A., Fernandes, N. F., Miranda, J. P. L., Souza, A. P., Lopes, M. R. S., and Antar, M. A., Elassiouti, I., and Allam, M. N.: Rainfall-runo References application of CT opensanother the opportunity complaint to of increase farmersshould bund test pertaining spacing CT thereby to with addressing wider loss bund of spacing than productiveAcknowledgements. the land. recommended. Futuregram called research “In searchriver of Basin”, sustainable catchments which and(WOTRO) is of basin-wide the funded Netherlands solidarities Organization by in for Scientificthe the the Research Netherlands (NWO), Blue and Foundation UNESCO-IHE, Nile Delft, Addis for Ababa the University, Ethiopia. Advancement of Tropical Research the future. It isand concluded adoption of that SCS integration in of high CT rainfall with areas of SCS Ethiopia. as can temporally. enhance Possibilities performance toanalysis reduce of the the number of CT plowing system with have CT to and be cost investigated. benefit Reduced surface runo tradition of cross plowingexperiment, were it reported has to been besystem shown constraints with that for SCS adoption integration can as of reducelogging well. locally surface behind adapted runo In SCS conservation this tillage wasalthough reduced the di and grainhigh yields fertility variations of among the wheat experimentalshowed and fields that (replications). tef Farmers they were interviews areincreased increased convenience convinced to that plow CT between increased SCS. grain Farmers plan yield. to continue They using also CT reported in Adoption of SCS inEthiopia is high constrained rainfall by areas reducedto crop in yield, frequent the accelerated breaching upper soil of erosionplowing Blue particularly SCS, up Nile due and which (Abbay) down in river the turn basin, slope. is in Water-logging caused behind by SCS and higher inconvenience surface to runo the 4 Conclusions and recommendations 5 5 30 25 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ects ff and soil loss from field ff ect of three soil and water , 2007. ff ects on runo ff ects of tooling and cultivation on soil-water stone, R., and Mulugeta, E.: Impact of Soil ff ff 1102 1101 , 2010. doi:10.5194/hess-11-1047-2007 nez, C.: Hydraulic conductivity, residue cover and soil surface ı ´ erent tillage systems in semiarid conditions, Soil Till. Res., 85, 13–26, ff ce, Ministry of Science and Technology, No. ET/M/2007/425, 2008. from a drained clay soil, Agr. Water Manage., 23, 161–180, 1993. ffi doi:10.5194/hess-14-627-2010 ff Ethiopian plateau flood basalts classificationcanol. and Geothermal spatial Res., distribution 81, of 91–111, magma 1998. types, J. Vol- ers, G., Leirs, H.,J.: Moeyersons, Interdisciplinary Jozef on-site Naudts, evaluation J.,Northern of Haregeweyn, Ethiopia, stone Soil N., Till. bunds Haile, Res., to M., 94, control and 151–163, soil 2007. Deckers, erosionthe on environment cropland in in Ethiopian273–320, and 2004. Eritrean highlands-a state of the art, Earth Sci. Rev., 64, On Soil Quality,International in: Symposium Advances Soil in quality Soiland Quality is Policy, for edited Land in by: Management: theBallarat, Science, MacEwan, Victoria, hands Practice 1996. R. of J. the and Carter, land M. manager. 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IFPRI Water Resources Discussion Development, MoWR, Addis Ababa, Ethiopia, 1993. methodologies to ungauged basins362, of 39–56, the 2008. Upper Blue Nile River Basin, Ethiopia, J. Hydrol., Conservation tillage techniques onprone dry North Wello spell Zone mitigation of and the Ethiopian erosion highlands, control Soil Till. in Res., the 97, drought- 19–36, 2007. Version 15, 3rd ed. Open University Press, UK, 2007. Cai, D., Jina, J., and Harmann,rainfall simulation, R.: Catena, Soil 75, management 191–199, e 2008. using on-site observations in627–638, sub-Saharan rainfed agriculture, Hydrol. Earth Syst. Sci., 14, and Conservation, edited by: Pimental, D., 27–62, Cambridge, 1993. conservation practices in Tigray, Ethiopia, Agr. Ecosy. Environ., 105, 29–40,– 2005. case-studies from Ethiopia and Eritrea, Catena, 36, 99–114,Applied 1999. Resource Management, 3, 391–411, 1993. and runo Chemoga Catchment,UNESCO-IHE, Upper Institute for Water Blue Education, Delft, Nile The Netherlands,2010. 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Macmillan Education Ltd. in cooperation with 5 5 30 25 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ) 1 − ) 1 − 462) 245) 440) 367) ± ± ± ± erent farm plots during (23 month ff 1 − ) Grain yield (kg ha )loss (t ha 1 1 − − 872)797)340)429) 2685 ( 1985 ( 2396 ( 1868 ( ± ± ± ± 1106 1105 concentration (gm l TTTT 4167 ( 3470 ( CTCT 2.21 3.02 5.41 10.73 sediment concentration and total soil loss of the di Crop type TillageWheat Biomass (kg ha Tef CT 5833 ( CT 3960 ( ff Biomass and grain yield of wheat and tef from conservation and traditional tillage at Runo Crop type TreatmentsWheat Average suspended sedimentTef TT Total soil TT 3.46 3.06 8.55 11.76 Table 2. Enerata, Ethiopia. August to 24 September 2010 at Enerata). Table 1. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

× is (b) ff was ff

. Runo

directing flow along fanya juu . Runoff was collected from directing flow along . Runoff was collected from fanya juu ed area in the mid altitudes of the Choke ed area in the mid was inserted 10 cm in to the soil with 15 cm in to the soil with 15 cm was inserted 10 cm fanya juu srupted plow pan and re n. Source of Satellite picture is Google Earth, ed area in the mid altitudes of the Choke ed area in the mid was inserted 10 cm in to the soil with 15 cm in to the soil with 15 cm was inserted 10 cm srupted plow pan and re n. Source of Satellite picture is Google Earth, trough 1108 1107 Runoff Direction of slope of Plot fence Plot ication (one farmer’s field). The three sides of the 5 m x 30 field). The three sides of the 5 m m ication (one farmer’s trough Runoff Direction of slope of Plot fence Plot Predominantly cultivat Predominantly ication (one farmer’s field). The three sides of the 5 m x 30 field). The three sides of the 5 m m ication (one farmer’s lower side is bound by the CT TT Predominantly cultivat Predominantly lower side is bound by the CT 30 m (b) (b) TT

30 m 30 30 m (b) (b) (a)

30 m 30 (a) 5 m 5 m 5 m 5 m Layout of a single replication (one farmer’s field). The three sides of the 5 m Fanya Juu Fanya Juu Fanya Juu Fanya Juu

Figure 1. Study sites at Enerata. Mountains, headwaters of the Blue Nile river basi Mountains, headwaters of the Blue Nile river 2009.

Figure 2. (a) Layout of a single repl surface runoff is whereby system tillage representation of the new conservation (b) Schematic the di infiltration through reduced, allowing more area is bound by a galvanized iron sheet fence that area is bound by a galvanized iron sheet fence height above the ground. The each block. selected for of CT and TT were randomly this area. Locations the contour by the invisible barriers.

Figure 1. Study sites at Enerata. Mountains, headwaters of the Blue Nile river basi 2009. this area. Locations of CT and TT were randomly selected for each block. selected for each block. of CT and TT were randomly this area. Locations height above the ground. The whereby surface runoff is system tillage representation of the new conservation (b) Schematic infiltration through the di reduced, allowing more Figure 2. (a) Layout of a single repl area is bound by a galvanized iron sheet fence that the contour by the invisible barriers. Study sites at Enerata. Predominantly cultivated area in the mid altitudes of the Choke collected from this area.Schematic Locations representation of of CT and the TT new were conservation randomly tillage selected for system each whereby block. surface runo Fig. 2. (a) 30 m area iswith bound 15 cm by height a above galvanized the iron ground. sheet fence The that lower side wasreduced, is inserted allowing bound 10 more cm by infiltration in the the through contour to by the the the disrupted invisible soil barriers. plow pan and redirecting flow along Fig. 1. Mountains, headwaters of the Blue2009. Nile river basin. Source of Satellite picture is Google Earth,

(13mm) of (13mm) 3

, 2010. About 2 m st

Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Runoff trough used in the study. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

3 on resistance starts at 10cm, which is the at 10cm, starts on resistance . (b) winged subsoiler. The winged subsoiler subsoiler. The winged . (b) winged rainfall event on a field with TT wheat. rainfall event on a field with TT wheat. -1

The resistance peaks at 20cm depth. Each point The resistance peaks at 20cm trough used ff (13mm) of (13mm) 3 Maresha Runo (c) Rise in penetrati Rise in

a high rainfall day on August 31

rainfall event on a field with TT , 2010. About 2 m st 1 Winged subsoiler. The winged − Runoff trough used in the study. Runoff trough used in the (b)

. on resistance starts at 10cm, which is the 10cm, at starts on resistance . (b) winged subsoiler. The winged subsoiler winged subsoiler. The . (b) winged rainfall event on a field with TT wheat. rainfall event on a field with -1 The resistance peaks at 20cm depth. Each point The resistance peaks at 20cm Maresha Maresha 1110 1109 Rise in penetrati Rise in (b) (c) (b)

a high rainfall day on August 31 a high rainfall day on August

(a) Enerata. at compaction Figure 4. Soil The picture was taken following a 36 mm d runoff was recorded by the trough from average depth of operation of the Maresha plow. of ten readings, is the average

Figure 3. (a) The traditional plow in Ethiopia, Figure 3. (a) sharp edges (MST, 2008). (c) wings with has a vertical share and was recorded by the trough from a 36 mm d ff (b) (c) (b)

The traditional plow in Ethiopia, (a) The picture was taken following The picture was taken following runoff was recorded by the trough from a 36 mm d trough from runoff was recorded by the at Enerata. compaction Figure 4. Soil average depth of operation of the Maresha plow. is the average of ten readings, of ten readings, is the average Figure 3. (a) The traditional plow in Ethiopia, The traditional Figure 3. (a) has a vertical share and wings with sharp edges (MST, 2008). (c) with wings has a vertical share and Soil compaction at Enerata. Rise in penetration resistance starts at 10 cm, which is the Fig. 4. average depth of operation ofpoint is the the Maresha average plow. of The ten readings. resistance peaks at 20 cm depth. Each Fig. 3. (a) subsoiler has a vertical share and wings with sharp edges (MST, 2008). wheat. in the study. The picture was(13 mm) taken of following runo a high rainfall day on 31 August 2010. About 2 m Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

) at 10 cm depth and (b) at 30 cm depth. depth and (b) at 30 cm ) at 10 cm (b) at 30 cm depth. nservation tillage (CT). (b) creates fill and spill type of creates fill and spill type of

r the application of co Figure 6: Soil moisture in TT and CT plots (a Figure 6: Soil moisture

plowing results in sharp horizontal profile of in sharp horizontal plowing results bout 10cm depth, thus leading to increased flow depth, thus leading bout 10cm (a)

(b) 1112 1111

at 10 cm depth and (a) nservation tillage (CT). d soil beneath the plowed layer d soil beneath the plowed creates fill and spill type of r the application of co

plowing results in sharp horizontal profile of plowing results bout 10cm depth, thus leading to increased flow depth, thus leading to increased bout 10cm (a) d soil beneath the plowed layer Typical profiles of soil before and after the application of conservation tillage (CT).

momentum and soil erosion. and soil momentum of soil before and afte Figure 5. Typical profiles that are laid along the slope, at a furrow bottoms The rugged profile of the undisturbe The rugged profile of the cross traditional subsurface flow. In contrast, Soil moisture in TT and CT plots (a) The rugged profile of the undisturbe cross traditional subsurface flow. In contrast, that are laid along the slope, at a furrow bottoms erosion. and soil momentum

Figure 5. Typical profiles of soil before and afte Fig. 6. Fig. 5. The rugged profile ofof the subsurface undisturbed flow. soilfurrow In beneath bottoms contrast, the that traditional plowed are layer crossflow laid creates momentum plowing along fill and results the soil and in erosion. slope, spill sharp at type horizontal about profile 10 cm of depth, thus leading to increased Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

that accumulated ff

traditional tillage (TT) tef. due to contour plowing (b) (b) (b) due to contour plowing wheat (b) (a) of infiltration, (b) Traditional tillage (TT) of infiltration, (b) Traditional T) fields are greener of infiltration, (b) Traditional tillage (TT) of infiltration, (b) Traditional ) at 10 cm depth and (b) at 30 cm depth. (b) at 30 cm depth and ) at 10 cm T) fields are greener h, generated more surface runoff that accumulated that accumulated surface runoff more h, generated in favor of infiltration, (b) taken at Enerata on September 8, 2010) taken at Enerata on September h, generated more surface runoff that accumulated that accumulated surface runoff more h, generated ff 1114 1113 taken at Enerata on September 8, 2010) taken at Enerata on September

(a) (a) conservation tillage (CT) fields are greener due to contour plowing (a) Figure 6: Soil moisture in TT and CT plots (a in TT and Soil moisture Figure 6: (b) (b) in TT and CT plots of (a) wheat Figure 7. Runoff and rainfall measured (b) tef. and rainfall measured in TT and CT plots of

behind SCS causing water-logging (Picture and subsoiling, which reduced surface runoff in favor growt and stunted color fields with yellowish fields: (a) Conservation tillage (C Figure 8: Wheat (a) (b)

ff

(b) (b) in TT and CT plots of (a) wheat Figure 7. Runoff and rainfall measured (b) tef. fields with yellowish color and stunted growt color and stunted fields with yellowish behind SCS causing water-logging (Picture fields: (a) Conservation tillage (C Figure 8: Wheat and subsoiling, which reduced surface runoff in favor Wheat fields: Runo fields with yellowish color and stunted growth, generated more surface runo and subsoiling, which reduced surface runo Fig. 8. behind SCS causing water-logging (Picture taken at Enerata on 8 September 2010). Fig. 7.