Hailu e al. Ag ic & Food Secu (2015) 4:19
DOI 10.1186/s40066-015-0038-0
RESEARCH
Soil e ili y s a us andwhea nu ien
con en inVe isol c opping sys ems o cen al
highlands o E hiopia
Hille e Hailu1,5*, Tekalign Mamo2, Riikka Keskinen3, E ik Ka l un4, Helu Geb ekidan5 and Taye Bekele6
Abs ac
Backg ound: Land deg ada ion educes ag icul u al p oduc i i y and poses a se ious h ea on ood secu i y s a us
o households. In E hiopia, a me s ha e been using only u ea and di-ammonium phospha e o mo e han 15 yea s.
Se e al epo s ha indica e lack o esponse o hese e ilize s, which could be due o limi a ion o nu ien s o he
han ni ogen and phospho us. The e o e, he p esen s udy was ini ia ed o e alua e he soil e ili y s a us o en si es
in cen al highlands Ve isols o E hiopia and whea nu ien con en .
Resul s: The physico-chemical p ope ies o soils showed ha he soils we e clayey in ex u e, neu al o sligh ly
alkaline (pH 7.2–7.9) and low o medium in hei o ganic ma e (1.6–3.2 %) con en . To al N con en was low in 100 %
o he samples while 80 % o he soil samples showed P de iciency (<10 mg kg−1). Exchangeable K, Ca and Mg in all
soil samples we e high, while a ailable sul u was low. On he o he hand, K o Mg a io a ied om 0.13:1 o 0.44:1,
indica ing Mg induced K de iciency. All soil samples we e adequa e when analyzed by ammonium bica bona e di-
e hylene i-amine pen a-ace ic acid ex ac able Cu (>0.5 mg kg−1), Fe (>5 mg kg−1), and Mn (>1 mg kg−1) con en s.
Howe e , 70 % o he samples we e de icien in Zn (<1.5 mg kg−1) con en . Mehlich 3 ex ac able B (<0.5 mg kg−1)
and acid ammonium oxala e ex ac able Mo (<0.1 mg kg−1) we e ound o be low in all soil samples. The plan analy-
sis da a showed ha all samples we e low in N, P and K, while high in Ca and Mg concen a ions. The de iciency o
issue K con en was no p edic ed by he soil exchangeable K es . Plan mic onu ien analysis showed ha Cu, Fe,
Mn and Cl concen a ions we e wi hin he su iciency ange while Zn was de icien in all o he samples.
Conclusions: Soil and/o issue es esul s a e indica i e o de iciency o N, P, K, S, Zn, B and Mo ha could be
amended by e ilize applica ion, al hough mo e da a a e needed o ho oughly suppo his conclusion. The highes
co ela ion ( > 0.90) be ween soil and plan nu ien con en was obse ed o P, K, Mg, Cu, Fe, Mn and Zn, implying
ha lag lea es a lowe ing s age can be used o calib a e soil and plan con en s o he de icien nu ien s.
Keywo ds: Soil, Plan , Nu ien , Soil e ili y, De icien , Adequa e, Fe ilize
© 2015 Hailu e al. This a icle is dis ibu ed unde he e ms o he C ea i e Commons A ibu ion 4.0 In e na ional License
(h p://c ea i ecommons.o g/licenses/by/4.0/), which pe mi s un es ic ed use, dis ibu ion, and ep oduc ion in any medium,
p o ided you gi e app op ia e c edi o he o iginal au ho (s) and he sou ce, p o ide a link o he C ea i e Commons license,
and indica e i changes we e made. The C ea i e Commons Public Domain Dedica ion wai e (h p://c ea i ecommons.o g/
publicdomain/ze o/1.0/) applies o he da a made a ailable in his a icle, unless o he wise s a ed.
Backg ound
In E hiopia, ag icul u e is he mains ay o he majo i y o
he popula ion and majo d i e o he na ional economy.
Ag icul u al p oduc ion has been highly dependen on
na u al esou ces o cen u ies [1]. Howe e , inc eased
human popula ion and o he ac o s ha e deg aded
he na u al esou ces in he coun y hus se iously
h ea ening sus ainable ag icul u e and ood secu i y
[2, 3]. Con inuous c opping and inadequa e eplace-
men o nu ien s emo ed in ha es ed ma e ials o lose
h ough e osion and leaching has been he majo causes
o soil e ili y decline [4]. This is pa icula ly e iden
in he in ensi ely cul i a ed a eas, adi ionally called
high-po en ial a eas ha a e mainly concen a ed in he
highlands o E hiopia. To ackle his p oblem, he coun-
y ini ia ed communi y-based pa icipa o y wa e shed
managemen [5], and o da e, i has ehabili a ed millions
o hec a es o deg aded land.
Open Access
*Co espondence: hille [email protected]
5 College o Ag icul u e and En i onmen al Sciences, Ha amaya
Uni e si y, Ha amaya, E hiopia
Full lis o au ho in o ma ion is a ailable a he end o he a icle
Page 2 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
Soil nu ien deple ion in smallholde a ming sys-
ems is ecognized as a causal o ce leading o ood
insecu i y and u al po e y in A ica [6, 7]. The a e o
annual soil mac onu ien deple ion in A ica was es i-
ma ed a 22kgNha−1, 2.5kgPha−1 and 15kgKha−1
o e 30 yea s o no use o insu icien use o e iliz-
e s [8]. In E hiopia, he deple ion a e o mac onu i-
en s, 122 kg N ha−1 yea −1, 13 kg P ha−1 yea −1 and
82kgKha−1yea −1, was es ima ed o be high [9]. Decline
in soil e ili y due o long- e m cul i a ion wi h li le o
no e ilize addi ions is he majo o m o land deg ada-
ion in mos o sub-Saha an A ica. Declining soil e ili y
has also been s essed o be he undamen al impedimen
o ag icul u al de elopmen and he majo eason o he
slow g ow h in ood p oduc ion in E hiopia [10]. The loss
o soil nu ien s in E hiopia is ela ed o cul u al p ac ices
such as low e ilize use, emo al o ege a i e co e
(such as s aw o s ubble) and bu ning plan esidues o
he annual bu ning o ege a ion on g azing land [11]. An
a e age quan i y o di-ammonium phospha e (DAP) and
u ea o 57kgha−1 was consumed o e he pe iod o 1995
o 2008 o whea p oduc ion [12].
Soil deg ada ion is common also in E hiopian Ve isols,
which co e abou 13 Mha o land. E hiopia anks hi d
in Ve isols abundance in A ica a e Sudan and Chad
[13]. Mo e han hal (8.6 Mha) o he Ve isols a e ound
in he cen al highlands wi h al i ude o mo e han 1500
me e s abo e sea le el (masl) [13, 14]. Abou 25% (1.9
Mha) o he Ve isols occu ing in he highlands a e cul-
i a ed [15]. The c ops ha a e commonly g own on Ve -
isols o E hiopia a e e , b ead whea , ba ley, chickpea,
len il and nige seed [16]. Recen ly, a me s in E hiopia
a e using modi ied plough called b oad bed make (BBM)
and ha es ing highe yields om mul iple c ops on he
same plo o land pe season [17].
P e iously, only ni ogen (N) and phospho us (P) we e
conside ed o be he limi ing nu ien s in Ve isols o
E hiopia [18]. Howe e , many soils in he highlands o
E hiopia a e poo in a ailable plan nu ien s and o ganic
ma e con en [19]. Recen ly, he esul s o na ional soil
e ili y mapping ini ia i e has also indica ed ha o he
nu ien s including K, S, Fe, Zn and B a e also ound o
be de icien in hese soils [20]. In addi ion o he high ix-
ing cha ac e is ics o Ve isols [21], lack o esponse o P
applica ion on cen al highland Ve isols o E hiopia may
be due o de iciency o nu ien s o he han P.
Soil es s a e commonly used o assess he su iciency
o de iciency o essen ial plan nu ien s. Al hough soil
es s p o ide in o ma ion abou a soil’s abili y o supply
plan a ailable nu ien s, i is an indi ec measu emen .
Plan analysis, on he o he hand, e eal he nu i ional
s a us o he plan di ec ly and when combined wi h
he soil es s can be used o e alua e he nu i ional
su iciency o he soil–plan sys em and u he o design
co ec i e ea men s [22]. The e o e, his s udy was ini-
ia ed wi h he objec i es o iden i ying nu ien limi a-
ions h ough soil analysis and whea nu ien s a us.
The esul s o he s udy se e in making sugges ions on
imp o ing e iliza ion and soil managemen o achie e
sus ainable c op p oduc ion on Ve isols o he cen al
highlands o E hiopia.
Me hods
Desc ip ion o sampling loca ions
Su ace soil (0–15 cm) and whea lea samples we e
aken om en si es o cen al highland Ve isols lis ed
in Table1. Global Posi ioning Sys em (GPS) was used o
iden i y he geog aphical loca ions (Addi ional ile1: Fig-
u e S1).
T adi ional a ming p ac ices o whea g owe s
In o ma ion ega ding a ming p ac ices o a me s a he
sampling si es is p esen ed in Table2. Fa me s ha e been
using only wo ypes o e ilize s o mo e han 15yea s,
u ea (46% N) and DAP (18% N, 46% P2O5). They usu-
ally apply one- hi d and wo- hi ds o he ni ogen dose
a sowing and ille ing s age, espec i ely. They use b oad
bed make (BBM), which is an oxen-d awn adi ional
wooden plough, modi ied o he cons uc ion o aised
beds and u ows o acili a e su ace d ainage h ough
he u ows be ween he beds so as o g ow c ops on
he beds [23]. The imp o ed b ead whea a ie y Digalu
(HAR-3116) was he mos common cul i a cul i a ed in
he s udy si es.
Soil andplan sampling
Twel e composi e su ace soil (0–15cm) samples we e
collec ed om each whea ields a he sampling loca-
ions. Each composi e soil sample comp ised o 15 sub
Table 1 Sampling loca ions andsi e cha ac e is ics
Loca ion (Dis ic ) La i ude (N) Longi ude (E) Al i ude (m)
Akaki (Me eno) 8o52′1″38o47′1″2400
Ambo (Kisole Odoli a) 8o59′2″37o51′30″2104
Che e Donsa (Habe u
Se e u) 8o57′60″39o06′28″2444
Deb e Zei (Denkaka) 8o41′36″39o 03′17″1880
Ginchi (Jemjem Legeba u) 9o3′37″38o 07′11″2200
Hole a (Gun u a) 9o3′58″38° 29′53′’2415
Mojo (Aje e Wolki e) 8°47′41″39°16′2″2275
Sheno (Wen u) 9o24′16″39o 21′23″2911
Tullu Bolo (Awash Bune) 8o38′56″38o 07′23″2115
Woliso (D/Ko a) 8o50′50″38o 48′37″2090
Page 3 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
samples collec ed in a zigzag pa e n wi hin each block
and mixed ho oughly ollowing a s anda d p ocedu e o
soil sampling and sample p epa a ion [24]. Six compos-
i e lag lea samples we e collec ed om each ield o he
sampling si es. Each composi e lea sample comp ised
150 andomly selec ed lag lea es a lowe ing s age. A
o al o 120 su ace soil (0–15cm) and 60 composi e lea
samples we e aken om he s udied si es. The a ea o
each expe imen al ield in all si es was abou 1ha.
Soil andplan analysis
Labo a o y analyses we e conduc ed a Deb e Zie
Ag icul u al Resea ch Cen e , E hiopia and a Na u al
Resou ces Ins i u e Finland ( o me MTT Ag i ood
Resea ch Finland) using he ollowing s anda d me h-
ods. Soil pa icle size dis ibu ion was de e mined by
hyd ome e me hod [25]. Soil pH and elec ical con-
duc i i y (EC) we e measu ed in soil:wa e ex ac
(1:2.5) acco ding o Rhoades [26]. CaCO3 con en was
de e mined using he calcime e me hod acco ding
o Black [27]. Soil o ganic ca bon (C) and o al ni o-
gen (N) con en we e de e mined by d y combus ion
me hods based on ISO 10694 [28] and ISO 13878 [29]
p o ocols, espec i ely. Soil o ganic ma e was cal-
cula ed by mul iplying soil o ganic ca bon by 1.724
assuming a e age C concen a ion o o ganic ma e
o 58%. A ailable phospho us was ex ac ed by 0.5N
sodium bica bona e solu ion as desc ibed by Olsen
e al. [30], and he ea e measu ed using Pe kin Elme
Op ima 8300 Induc i ely Coupled Plasma–Op ical
Emission Spec ome e (ICP-OES). Sul a e was de e -
mined in he soil ex ac by he u bidi y me hod using
spec opho ome e on ansmi ance a a wa e leng h
o 420nm acco ding o Williams and S einbe gs [31].
One mola neu al ammonium ace a e (pH=7) was
used o ex ac he exchangeable ca ions (Ca, Mg, K
and Na) [32]. Ca ions we e hen de e mined using ICP-
OES. A ailable mic onu ien s (Cu, Fe, Mn and Zn)
we e ex ac ed wi h ammonium bica bona e di-e hylene
i-amine pen a-ace ic acid (AB-DTPA) as desc ibed
by Sol anpou and Schwab [33] and we e measu ed by
ICP-OES. Mehlich 3 ex ac ion was accomplished by
mixing 2.5g o soil and 25ml o Mehlich 3 solu ion
[0.2 M ace ic acid (CH3COOH), 0.25 M ammonium
ni a e (NH4NO3), 0.015M ammonium luo ide (NH4F),
0.013 M ni ic acid (HNO3), and 0.001 M e hylene
diamine e a-ace ic acid (EDTA)], shaking o 5min,
and il e ing h ough a blue ibbon il e pape [34].
The il a e was analyzed o a ailable bo on using ICP-
OES. Molybdenum was ex ac ed wi h acid ammonium
oxala e (pH=3) solu ion [35] and hen analyzed using
ICP-OES.
Lea es we e i s washed wi h dis illed wa e , o en
d ied a 60–70°C o a cons an weigh , g ound, passed
h ough 2-mm sie e and placed in pape bags. To al
ni ogen in plan s was de e mined using Kjeldahl diges-
ion p ocedu e as desc ibed by B emne and Mul aney
[36]. Plan diges s (using concen a ed HNO3 and 30%
H2O2) we e p epa ed and analyzed o Ca, Mg, Cu, Fe,
Mn and Zn using A omic Abso p ion Spec opho ome e
while P concen a ion o he diges s was measu ed wi h a
spec opho ome e and he K concen a ion wi h a lame
pho ome e using equi ed s anda d solu ions. Plan
chlo ide was de e mined by TRAACS 800 Analyze using
deionized wa e as an ex ac an [37].
S a is ical analysis
Desc ip i e s a is ics was applied o calcula ion o means
and s anda d e o s. Co ela ion analysis was pe o med
o assess ela ionships among soil and plan nu ien
con en s.
Resul s anddiscussion
Soil cha ac e is ics
Pa icle size dis ibu ion
The esul s o soil ex u e, as p esen ed in Table 3
e ealed ha he pa icle size dis ibu ion o he su ace
soil (0–15cm) o all he expe imen al si es was domi-
na ed by clay (abo e 53%) excep a Sheno (47%).The
ela i ely high clay con en s obse ed in his s udy ag ee
wi h he indings o Kama a e al. [38] and Lemma and
Smi [39], who also epo ed clay le el o abo e 50% in
Ginichi, cen al highlands Ve isols o E hiopia. This is
u he suppo ed by Debele [14] and Tesgaye [40], who
epo ed ha Ve isols in E hiopian gene ally con ain
mo e han 40% clay in he su ace ho izon.
Table 2 Fe ilize applica ion a es and p e ious yea
c opping his o y o  whea g owe s in cen al highlands
o E hiopia
Loca ion (Dis ic ) Fe ilize used P e ious c op
N (kgha−1) P (kgha−1)
Akaki (Me eno) 60 20 Whea
Ambo (Kisole Odoli a) 65 20 Te
Che e Donsa (Habe u Se e u) 86 25 Len il
Deb e Zei (Denkaka) 90 25 Len il
Ginchi (Jemjem Legeba u) 75 20 Te
Hole a (Gun u a) 78 20 Len il
Mojo (Aje e Wolki e) 83 30 Te
Sheno (Wen u) 60 30 Whea
Tullu Bolo (Awash Bune) 63 30 Te
Woliso (D/Ko a) 62 25 Te
Page 4 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
Soil pH andEC
As pe he a ings o E hiopian soils by Mu phy [41] and
Taddese [42], he soil pH was ound o ange om neu-
al o sligh ly alkaline wi h pH anging om 7.2 o 7.9
(Table4). Simila esul s we e ob ained by Debele [14]
and Kebede and Cha les [43].This pH ange is a o a-
ble o mos c ops [42, 44]. The elec ical conduc i i y
anged om 0.1 o 0.22dSm−1 in su ace soil samples
indica ing ha hese soils ha e a low con en o soluble
sal s and ha he e is no dange o salini y (Table4).
Soil o ganic ma e andC oN a io
The o ganic ma e con en s we e in he ange o 1.6–
3.2 % on he su ace soils (Table 4). These alues all
unde low o mode a e ange based on he a ings o soil
es alues es ablished by Taddese [42].The alues a e
simila o mos cul i a ed soils o E hiopia [38, 45] which
is a ibu ed o land use his o y such as comple e emo al
o biomass om he ield and apid a e o mine aliza ion
[46]. The C o N a io o he su ace soil samples a ied
om 10 o 15 (Table4), which is wi hin he no mal ange
o a able soil [47].
To al N
Da a on o al ni ogen o he su ace soils a e p esen ed
in Table4. To al ni ogen le els be ween 0.1 and 0.2%
a e aken as low while hose below 0.1% a e e y low o
opical soils [48]. I , he e o e, ollows ha soils o he
s udy a eas a e low o e y low in hei o al ni ogen s a-
us. To al ni ogen closely ollowed he end o o ganic
ma e . Gene ally, a si e low in o ganic ma e was also
low in o al ni ogen. This suppo s ea lie s udies in he
a ea by Debele [14] and Beyene [49]. One o he cha ac-
e is ic ea u es o opical en i onmen is i s high em-
pe a u e which leads o apid loss o soil o ganic ma e
due o ola iliza ion. Soil e osion due o s eep slopes and
hea y ain all as well as leaching, may ha e con ibu ed
o ni ogen loss. Ce ainly, i is one o he mos de icien
elemen s in he opics o c op p oduc ion [11, 50, 51].
Unde local condi ions, in addi ion o he abo e ac o s,
con inuous c op emo al also con ibu es he low o ganic
ma e con en in he s udy a eas.
A ailable P
A ailable P (Olsen ex ac able) in he s udied si es a -
ied be ween 3.8 and 14.6mgkg−1 (Addi ional ile2: Fig-
u e S2). I was ound o be de icien (<10mgkg−1) and
medium (be ween 10 and 17mgkg−1) in 80 and 20% o
he samples, espec i ely, when compa ed wi h he alues
Table 3 Pa icle (sand, sil andclay) size analysis and ex-
u al classes o  he s udy si es (n=12)
a Indica e mean
b Indica e s anda d e o in pa en heses
Loca ion (Dis ic ) % Sand % Sil % Clay Tex u al class
Akaki (Akaki) 15a (0.43)b19 (0.73) 67 (0.2) Hea y clay
Ambo (Kisole Odoli a) 18 (0.35) 16 (0.7) 66 (0.88) Hea y clay
Che e Donsa (Habe u
Se e u) 22 (0.57) 25 (0.47) 54 (0.6) Clay
Deb e Zei (Denkaka) 16 (0.3) 18 (0.2) 66 (0.4) Hea y clay
Ginichi (Jemjem Lege-
ba u) 22 (0.47) 20 (0.77) 57 (1.1) Clay
Hole a (Gun u a) 21 (0.38) 20 (0.48) 59 (0.47) Clay
Mojo (Aje e Wolki e) 19 (1.3) 18 (1.2) 63 (0.5) Hea y clay
Sheno (Wen u) 23 (0.37) 30 (0.89) 47 (0.91) Clay
Tullu Bolo (Awash Bune) 17 (0.4) 24 (0.4) 59 (0.37) Clay
Woliso (D/Ko a) 25 (0.73) 22 (0.49) 53 (0.91) Clay
Table 4 Soil pH, elec ical conduc i i y (EC), soil o ganic ma e (SOM), o al ca bon(TC), o al ni ogen (TN), ca bon
oni ogen a io(C:N) andsul a e-S con en o  he s udy si es (n=12)
a Indica es mean
b Indica es s anda d e o in pa en heses
Loca ion (Dis ic ) pH (1:2.5) EC (1:2.5) SOM TC TN C:N SO4-S
dS/m (%) (%) (%) (mgkg−1)
Akaki (Akaki) 7.4a (0.01)b0.149 (0.014) 1.9 (0.005) 1.2 (0.003) 0.1 (0.0003) 12.3 (0.06) 1.8 (0.06)
Ambo (Kisole Odoli a) 7.9 (0.02) 0.104 (0.004) 2.7 (0.01) 1.6 (0.003) 0.12 (0.0009) 13 (0.07) 1.5 (0.13)
Che e Donsa (Habe u Se e u) 7.8 (0.05) 0.197 (0.01) 1.9 (0.01) 1.1 (0.004) 0.1 (0.001) 11.6 (0.1) 1.2 (0.09)
Deb e Zei (Denkaka) 7.9 (0.02) 0.173 (0.005) 2.7 (0.01) 1.69 (0.01) 0.11 (0.001) 14.8 (0.08) 1.4 (0.04)
Ginichi (Jemjem Legeba u) 7.8 (0.04) 0.224 (0.003) 2.3 (0.01) 1.34 (0.004) 0.11 (0.0007) 12.7 (0.05) 1.4 (0.13)
Hole a (Gun u a) 7.8 (0.02) 0.11 (0.002) 2.3 (0.005) 1.32 (0.003) 0.11 (0.001) 12.5 (0.1) 1.9 (0.13)
Mojo (Aje e Wolki e) 7.2 (0.04) 0.125 (0.002) 2.8 (0.003) 1.65 (0.002) 0.12 (0.001) 14.3 (0.1) 1.7 (0.11)
Sheno (Wen u) 7.3 (0.07) 0.144 (0.01) 3.2 (0.003) 1.87 (0.002) 0.19 (0.001) 9.9 (0.05) 1.7 (0.05)
Tullu Bolo (Awash Bune) 7.2 (0.03) 0.12 (0.005) 1.6 (0.01) 0.94 (0.004) 0.08 (0.0003) 12 (0.09) 1.4 (0.13)
Woliso (D/Ko a) 7.8 (0.02) 0.201 (0.01) 2.1 (0.01) 1.21 (0.003) 0.11 (0.001) 10.7 (0.04) 2.1 (0.21)
Page 5 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
epo ed by Co enie [32]. This esul is in ag eemen
wi h he indings o Debele [14]; Mamo e al. [18]; Mamo
e al. [20]; Tesgaye [40]; Mamo and Haque [52]; Geb ese-
lassie [53] and Negassa and Geb ekidan [54]. The modes
le el o annual P applica ion (20–30kgha−1) in he o m
o DAP e ilize o e 15yea s was insu icien o aise
he soil P le els and sa is y c op equi emen .
A ailable sul u
Calcium chlo ide ex ac able sul u (sul a e-S) in he
s udy si es anged om 1.2 o 2.1mgkg−1 (Table4). The
a ailable S con en s o samples om all si es we e ound
o be de icien assuming 5mgkg −1 S as c i ical le el
(Table5).
Exchangeable bases andca ion exchange capaci y
In neu al Ve isols, he exchangeable si es a e occu-
pied mainly by calcium (Ca) and magnesium (Mg) and
o a lesse ex en by po assium and sodium [43]. Simi-
la ly in he p esen s udy, he p edominan exchange-
able ca ion, which accoun s o mo e han 80% o he
exchange complex was Ca++ ollowed by Mg++, K+
and Na+. Exchangeable Ca and Mg con en in he s ud-
ied soils anged om 27 o 49cmol(+)kg−1 and 4.7 o
10cmol(+)kg−1, espec i ely (Table6). Acco ding o he
a ing sugges ed by Hazel on and Mu phy [47], bo h Ca
and Mg a e in high ange a all he si es (Table5). The
exchangeable K anged be ween 1.3 and 2.3cmol(+)kg−1,
which is in a e y high ange (Tables5, 6). Gene ally, he
ai ly high le el o exchangeable Ca, Mg and K is consis -
en wi h he indings o ea lie s udies [38, 39, 45].
I has been sugges ed ha he p opo ions o he basic
ca ions o he e ec i e ca ion exchange capaci y a e mo e
ele an o plan pe o mance han he ac ual le els
[47]. Acco ding o Abbo [60], he po assium sa u a ion
pe cen age (3.2–5.4%) o he s udied soils was ound o
be desi able p opo ion o many plan s (Table6). Ne -
e heless, an agonis ic e ec s could exis when disp o-
po iona e quan i ies o exchangeable ca ions a e p esen
in he soil. Po assium o magnesium a io o he s udied
soils a ied om 0.17:1 o 0.44:1 (Table6), which indi-
ca ed Mg-induced K de iciency using he a ing o Loide
[61]. This can be co ec ed by K applica ion o b ing he
K o Mg a io close o 0.7:1. The low K o Mg a ios may
esul in K adso p ion o ca ion exchange si es, which
educe K ac i i y in he soil [62]. Many soils wi h e -
miculi ic o micaceous componen s o he clay ac ion
ha e a p e e en ial adso p ion o K+ o e Ca2+ o Mg2+
[63, 64]. I he e is a high p e e en ial K adso p ion on he
exchange si es o clay mine als, he amoun o K deso b-
ing may hen decline, esul ing in a educed K up ake a
low soil exchangeable K o Mg a io. The e o e, a emp s
should be made o supply he plan s wi h po assium in
physiologically co ec a io and in a sus ainable manne .
Ve isols usually ha e a ela i ely high CEC, which
anges be ween 20 and 45cmol(+) kg−1 soil and e en
mo e [65]. In E hiopia, Debele [14] epo ed ha nea ly
all he Ve isols ha e high CEC o 35–70cmol(+)kg−1.
Acco ding o he a ing o Hazel on and Mu phy [47],
CEC o he s udied soils we e e y high and anged
be ween 37 and 58cmol(+)kg−1(Table6). The e y high
alue o CEC is mainly due o high clay con en and p e-
dominance o 2:1 laye clay mine als.
Mic onu ien s
The AB-DTPA ex ac able Cu anged om 2.9 o
6mgkg−1 in he su ace soils (Addi ional ile3: Figu e
S3). Cu was ound adequa e in all he samples as com-
pa ed wi h he alues o Sol anpou [56] and Jones [57]
(Table5). The esul was simila o ha o Abe a and
Kebede [66], who epo ed ha Cu concen a ion is a
an adequa e le el in he cen al highlands o E hiopia.
This was u he suppo ed by E hioSIS inding. The
AB-DTPA ex ac able Fe a ied om 22 o 77mgkg−1
(Addi ional ile 3: Figu e S3). In his s udy, conside -
ing 5mgkg−1 AB-DTPA ex ac able Fe as c i ical, sam-
ples om all si es we e ound o ha e su icien le el o
a ailable Fe (Table5). The esul was simila o he ind-
ing o I anna [67] who epo ed adequa e con en o soil
Fe in E hiopian Ve isols. Howe e , de iciency o Fe was
eco ded by Abe a and Kebede [66] in cen al highland
Ve isols o E hiopia. The inding o E hioSIS has also
indica ed ha i on de iciency exis ed in soils o ou
majo egions (Tig ay, Amha a, O omia and Sou he n),
bu i was mo e p e alen (41%) in Tig ay ag icul u al
soils.
The AB-DTPA ex ac able Mn anged om 22 o
100mgkg−1 (Addi ional ile3: Figu e S3). Based on he
Table 5 C i ical le els o  mac o and mic onu ien s
wi hdi e en soil es s as epo ed bydi e en au ho s
Elemen s Me hod used C i ical le els Re e ences
P Olsen 10–17 mg kg−1[32]
K NH4OAc, pH = 7 0.3–0.7 cmol kg−1[47]
Ca NH4OAc, pH = 7 5–10 cmol kg−1[47]
Mg NH4OAc, pH = 7 1–3 cmol kg−1[47]
Sul a e-S CaCl25 mg kg−1[55]
Cu AB-DTPA 0.5 mg kg−1[56, 57]
Fe AB-DTPA 5 mg kg−1[56, 57]
Mn AB-DTPA 1 mg kg−1[56, 57]
Zn AB-DTPA 1.5 mg kg−1[56, 57]
Mo AAO 0.1–0.5 mg kg−1[35, 58]
B Mehlich 3 0.5–1 mg kg−1[58, 59]

Page 6 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
c i ical alue gi en by Sol anpou [56] and Jones [57],
samples om all si es we e ound o ha e su icien le el
o a ailable Mn (Table5). The su icien le els o Mn in all
he si es we e consis en wi h indings o I anna [67] who
epo ed adequa e con en o soil Mn in E hiopian Ve i-
sols. Likewise, E hioSIS epo ed su icien Mn le els in
di e en soil ypes o E hiopia including Ve isols. Ne -
e heless, a de icien le el o Mn was eco ded by Abe a
and Kebede [66] in cen al highland Ve isols o E hiopia.
Zinc has low mobili y in soils and endency o being
adso bed on clay pa icles [68]. As shown in Addi ional
ile3: Figu e S3, AB-DTPA ex ac able Zn in he su ace
soils (0–15cm) anged om 1.1 o 2.7mgkg−1. Howe e ,
he alues eco ded we e lowe han he c i ical le el o
1.5mgkg−1 as es ablished by Sol anpou [56] and Jones
[57] excep in Ambo, Hole a and Sheno (Table5). In con-
i ma ion wi h his s udy, Asegelil e al. [69] epo ed Zn
de iciency in 78.4% o he soil samples collec ed om
Ve isols o E hiopia. This was u he suppo ed by
Abe a and Kebede [66] who epo ed de iciency o Zn in
98% o he soil samples collec ed om cen al highland
Ve isols o E hiopia. A ecen inding by Be eke e al.
[70] also suppo ed Zn de iciency on E hiopian Ve isols.
Simila ly, his was epo ed by he indings o E hioSIS.
The inhe en ly low con en o zinc in hese soils may ha e
been u he deple ed by in ensi e c opping. The poo
a ailabili y o Zn in 70% o he si es needs immedia e
in e en ion o imp o e whea p oduc ion.
Resul s epo ed by di e en esea che s [59, 71–73]
indica e ha Mehlich 3 ex ac s compa able amoun s
o B as he ho wa e -soluble me hod. Consequen ly,
we ha e used he su iciency ange (0.5–1mgkg−1) o B
ex ac ed using ho wa e -soluble me hod and applied i
o Mehlich 3 ex ac able B. Samples om all si es in he
s udy we e ound o be de icien (Tables5, 6). Compa i-
son o he acid ammonium oxala e ex ac able Mo wi h
he su iciency ange o 0.1–0.3mgkg−1 [35, 58] showed
ha samples om all si es we e also ound o be de icien
(Tables5, 6).
Whea nu ien s a us
Da a on whea lag lea es analysis a lowe ing s age
showed ha N con en a ied om 1.4 o 2% (Addi-
ional ile2: Figu e S2). Tissue N concen a ion o sam-
ples om all si es was below he c i ical alue o 3.6%,
sugges ing he e we e insu icien N le els in he plan
[74] (Table7). To inc ease he pool o N a ailable o c op
g owing, ag icul u al ac i i ies should ocus on p ope N
managemen ia applica ion o N e ilize s and o ganic
amendmen s and cul i a ion o whea a e legumes.
Table 6 Exchangeable bases, ca ion exchange capaci y (CEC), K sa u a ion pe cen age, K oMg a io, a ailable molybde-
num (Mo) andbo on (B) con en o  he s udy si es (n=12)
a Indica es mean
b Indica es s anda d e o in pa en heses
Loca ion (Dis ic ) Exchangeable bases (cmol(+) kg−1) CEC K/CEC K:Mg AAO (mgkg-1) Mehlich3 (mgkg−1) B
Ca Mg K Na (cmol(+) kg-1) (%) Mo
Akaki (Akaki) 38a (0.17)b9.4 (0.03) 1.6 (0.002) 0.16 (0.002) 49.4 (0.16) 3.2 0.17:1 0.003 (0.002) <0.5
Ambo (Kisole Odoli a) 45.2 (0.08) 7 (0.02) 1.8 (0.008) 0.1 (0.003) 54.6 (0.09) 3.3 0.26:1 0.01 (0.01) <0.5
Che e Donsa (Habe u
Se e u) 32.8 (0.2) 5.2 (0.5) 1.8 (0.16) 0.27 (0.006) 42.1 (0.15) 4.3 0.35:1 0.005 (0.002) <0.5
Deb e Zei (Denkaka) 49 (0.11) 5.2 (0.01) 2.3 (0.01) 0.07 (0.002) 56.5 (0.13) 4.1 0.44:1 0.02 (0.01) <0.5
Ginichi (Jemjem Legeba u) 48.8 (0.04) 6.7 (0.03) 1.9 (0.008) 0.17 (0.004) 58 (0.03) 3.3 0.28:1 0.01 (0.01) <0.5
Hole a (Gun u a) 34.1 (0.1) 8 (0.04) 1.5 (0.02) 0.18 (0.003) 44.3 (0.16) 3.4 0.19:1 0.01 (0.005) <0.5
Mojo (Aje e Wolki e) 32.4 (0.17) 9.8 (0.12) 1.9 (0.007) 0.13 (0.003) 44.5 (0.23) 4.3 0.19:1 0.01 (0.005) <0.5
Sheno (Wen u) 28.3 (0.11) 9.7 (0.03) 1.3 (0.008) 0.11 (0.005) 39.8 (0.15) 3.3 0.13:1 0.02 (0.008) <0.5
Tullu Bolo (Awash Bune) 27.1 (0.2) 8.8 (0.07) 2.1 (0.02) 0.41 (0.002) 38.8 (0.3) 5.4 0.24:1 0.01 (0.003) <0.5
Woliso (D/Ko a) 30.8 (0.08) 4.7 (0.02) 1.8 (0.002) 0.08 (0.005) 37.8 (0.11) 4.8 0.38:1 0.01 (0.003) <0.5
Table 7 Su iciency anges o  nu ien con en in whea
( lag lea es a  lowe ing s age)
Nu ien s Su iciency ange Re e ences
N (%) 3.6–4.5 [74]
P (%) 0.2–0.5 [76]
K (%) 1.5–3 [77]
Ca (%) 0.2–1 [76]
Mg (%) 0.15–0.5 [77]
Cu (mg kg−1) 4.5–15 [76]
Fe (mg kg−1) 30–200 [76]
Mn (mg kg−1) 20–150 [76]
Zn (mg kg−1) 18–70 [76]
Page 7 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
As a consequence, he pool o N po en ially a ailable
o he c op inc eases, which should imp o e he N s a-
us and yield o c ops [75]. Phospho us concen a ion
in whea lea es anged om 0.05 o 0.15% a lowe ing
s age (Addi ional ile2: Figu e S2). Acco ding o Plank
and Donohue [76], P was de icien in samples om all
si es bu he alues we e close o he lowe limi o su -
iciency ange a h ee si es (Mojo, Sheno and Tullu Bolo)
(Table7). Simila ly, K anged om 0.8 o 1.4% and was
ound o be de icien in samples om all si es (Addi ional
ile2: Figu e S2). Abou 70% o he issue K con en o
he lag lea es was sligh ly unde he lowe limi o he
su iciency ange sugges ed by Jones [77]. The de icien
issue K con en was no p edic ed by he soil exchange-
able K es . Simila ly, esponse o K has been obse ed on
E hiopian Ve isols wi h high amoun o ammonium ace-
a e ex ac able K [78]. This was u he suppo ed by he
indings o Suba and S i as a a [79], who epo ed ha
Ve isols wi h high exchangeable and non-exchangeable
K showed a esponse o applied K, hough he esponse
was di e en depending on he ype o plan . The poo
ag eemen be ween he soil K s a us and esponse o K
e ilize is due o he ac ha K esponse is a ec ed by
o he soil a iables like K sa u a ion o ca ion exchange
capaci y, he p opo ion o K o o he basic ca ions and
K ixa ion capaci y o clay mine als. In his ega d, he K
ecommenda ions which depend on he ca ion exchange
capaci y and/o clay con en o he soil ha e been com-
piled [80, 81]. Fo example, in India, Suba and S i as a a
[79] ha e quad upled K c i ical le el o smec i e- ich
swell and sh ink soils. Mo eo e , E hioSIS has es ablished
a c i ical alue o Mehlich 3 ex ac able K o 190mgkg−1
based on ield c op K esponse and soil analysis esul s,
sugges ing he need o amend he h eshold alue o K o
ge a common and ealis ic ecommenda ion o K ac oss
all Ve isols o E hiopia o sus ainable c op p oduc ion.
Calcium and magnesium con en o he whea lea es
anged om 0.3 o 0.5% and 0.25 o 0.83%, espec i ely
(Addi ional ile2: Figu e S2). Bo h Ca and Mg we e ound
o be wi hin he su iciency ange made in Plank and
Donohue [58] and Jones e al. [74], espec i ely (Table7).
Rega ding whea mic onu ien issue concen a ions,
Cu concen a ion in whea lea es anged om 6.1 o
9.6mgkg−1, Fe om 71 o 97mgkg−1, Zn om 7.5 o
18mgkg−1, Mn om 29 o 100mgkg−1 and Cl om 0.54
o 1.3mgkg−1 (Addi ional ile3: Figu e S3). All he plan
samples we e su icien in Cu, Fe and Mn as gi en in Plank
and Donohue [76] and Jones e al. [77] (Table7). Since he
con en s o Fe and Mn in all he samples we e a abo e
he c i ical le els, hei de iciency may no be expec ed in
he o eseeable u u e as a as whea c op is conce ned.
Zinc s a us o b ead whea lag lea a lowe ing s age was
de icien acco ding o he su iciency ange in Plank and
Donohue [76] which ag eed wi h he low le els o Zn in
he soil (Table7). Tissue Cl concen a ion o all he sam-
ples was abo e he c i ical alue o 0.4% [82], sugges ing
he e we e su icien Cl in he soils (Table8).
Soil andwhea nu ien con en ela ionships
In e p e a ion o soil es esul s and plan analysis da a
is essen ial o u he de elopmen o nu ien manage-
men . Addi ional iles 2 (Figu e S2) and 3 (Figu e S3) p e-
sen ed he in e ela ion be ween soil and whea lag lea
nu ien con en s a lowe ing s age, collec ed om en
Ve isols o cen al highlands o E hiopia. Soil and issue
nu ien concen a ions we e expec ed o be posi i ely
co ela ed o mos nu ien s because he concen a ion o
a pa icula nu ien in he plan is gene ally g ea e when
he concen a ion in he soil is g ea e [51]. Soil o al N
and C:N a io had no signi ican co ela ion (un ela ed)
wi h plan N con en a lowe ing s age. Howe e , soil
P, K, Ca, Mg, Cu, Fe, Mn and Zn concen a ions exhib-
i ed a signi ican posi i e co ela ion wi h issue nu i-
en concen a ions. This indica ed ha soil o al N did
no p opo ionally al e in e nal plan N con en , and i
was less a ec ed by changes in soil o al N concen a ion
han o he nu ien s. The mobili y o N in he soil makes
i di icul o ge a solid ep esen a ion o he a ailable N
concen a ion in soils. The highes co ela ion (  >0.90)
be ween soil and plan nu ien con en was obse ed
o P, K, Mg, Cu, Fe, Mn and Zn (Addi ional ile2: Figu e
S2, Addi ional ile3: Figu e S3), implying ha lag lea es
a lowe ing s age can be used o calib a e soil and plan
con en s o he de icien nu ien s.
Conclusions
F om he p esen s udy, i can be concluded ha he soil
analysis da a o whea ields in cen al highland Ve isols
Table 8 Chlo ide con en o whea lea samples om en
whea g owing a eas o cen al highland Ve isols (n=6)
a Indica es mean
b S anda d e o in pa en heses
Loca ion (Dis ic ) Cl (%)
Akaki (Akaki) 1a (0.04)b
Ambo (Kisole Odoli a) 1.1 (0.03)
Che e Donsa (Habe u Se e u) 1.1 (0.05)
Deb e Zei (Denkaka) 1 (0.05)
Ginichi (Jemjem Legeba u) 1.2 (0.03)
Hole a (Gun u a) 1.2 (0.1)
Mojo (Aje e Wolki e) 1.3 (0.1)
Sheno (Wen u) 0.94 (0.06)
Tullu Bolo (Awash Bune) 0.84 (0.01)
Woliso (D/Ko a) 0.54 (0.01)
Page 8 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
o E hiopia showed de iciency in he le els o N, P, S, Zn,
Mo and B. Mo eo e , he plan analysis da a om he
same si es indica ed ha whea plan s we e de icien in
N, P, Zn and K. The nu ien de iciencies iden i ied in his
s udy could be due o ei he inhe en ly low a ailabili y o
hese nu ien s in he soils o as a consequence o con-
inuous in ensi e c opping wi hou applying e ilize o
manu e con aining hese nu ien s. The esul s o his
s udy show he need o u he s udies in he de icien
a eas o de e mining whea esponse o balanced e ili-
za ion. Fu he esea ch on a wide ange o whea g ow-
ing E hiopian highland Ve isols is desi able o ob ain
holis ic iew o whea nu i ion. The allies and ain-
ing p og ammes o he a me s should be a anged o
inc easing awa eness ega ding he bene i s o ino ganic
e ilize s o he han DAP and u ea in imp o ing soil e -
ili y, nu ien s a us and c op p oduc ion.
Abb e ia ions
NH4OAc: ammonium ace a e; AB-DTPA: ammonium bica bona e di-e hylene
i-amine pen a-ace ic acid; AAO: acidic ammonium oxala e; CEC: ca ion
exchange capaci y; DAP: di-ammonium phospha e; EDTA: e hylene diamine
e a-ace ic acid; EC: elec ical conduc i i y; E hioSIS: E hiopian soil in o ma-
ion sys em; FAO: ood and ag icul u e o ganiza ion; GPS: global posi ioning
sys em; ICP-OES: induc i ely coupled plasma-op ical emission spec ome e ;
SOM: soil o ganic ma e ; TC: o al ca bon; TN: o al ni ogen.
Au ho s’ con ibu ions
HH and TM concei ed he s udy. All au ho s pa icipa ed in he design and
coo dina ion. HH collec ed and analyzed he samples and in e p e ed he
da a, which was pa o he Doc o ial hesis o Soil Science a Ha amaya
Uni e si y, E hiopia. All he au ho s also helped o d a he manusc ip as
well as app o ed he inal manusc ip . All au ho s ead and app o ed he inal
manusc ip .
Au ho s’ in o ma ion
HH is a doc o ial candida e in he depa men o Soil Science, College o
Ag icul u e and En i onmen al Sciences, Ha amaya Uni e si y, Ha amaya,
E hiopia. She is a lec u e in college o Na u al and Compu a ional sciences
a Wollo Uni e si y, Wollo, E hiopia. TM is a p o esso o Soil Science, Mins e ’s
Ad iso /S a e Mins e a E hiopian Minis y o Ag icul u e. TM ecei ed his PhD
deg ee in soil chemis y and e ili y om Abe deen Uni e si y, Sco land. RK
is a senio esea che o soil and plan nu i ion a Na u al Resou ces Ins i u e
Finland (Luke), Jokioinen, Finland. RK ob ained he PhD deg ee in Ag icul u e
and Fo es y om Helsinki Uni e si y, Finland. EK is an associa e p o esso
in Soil Science and an in e na ional consul an in soil e ili y mapping and
e ilize ecommenda ions a E hiopian Ag icul u al T ans o ma ion Agency
(ATA). EK ecei ed his PhD deg ee in Soil Science om Swedish Uni e si y o
Ag icul u al Sciences. HG is a p o esso o Soil Science a Ha amaya Uni e si y,
Ha amaya, E hiopia. HG ob ained his PhD deg ee in Soil and Wa e Science
om Uni e si y o A izona, Tucson, A izona. TB is a senio esea che o soil sci-
ence a ATA, Addis Ababa, E hiopia. TB ob ained his PhD deg ee in Soil Science
om Jus us-Liebig Uni e si y, Giessen, Ge many.
Addi ional iles
Addi ional ile 1: Figu e S1. Geog aphical map o he sampling si es.
Addi ional ile 2: Figu e S2. Li e a u e c i ical le els and plan s. soil
mac o-nu ien con en s o he s udy si es.
Addi ional ile 3: Figu e S3. Li e a u e c i ical le els and plan s. soil
mic o-nu ien con en s o he s udy si es.
Au ho de ails
1 College o Na u al and Compu a ional Sciences, Wollo Uni e si y, Dessie,
E hiopia. 2 Minis y o Ag icul u e, Addis Ababa, E hiopia. 3 Na u al Resou ces
Ins i u e Finland (Luke), 31600 Jokioinen, Finland. 4 Depa men o Soil
and En i onmen , Swedish Uni e si y o Ag icul u al Sciences, Uppsala,
Sweden. 5 College o Ag icul u e and En i onmen al Sciences, Ha amaya
Uni e si y, Ha amaya, E hiopia. 6 Ag icul u al T ans o ma ion Agency, Addis
Ababa, E hiopia.
Acknowledgemen s
The au ho s g a e ully acknowledge he In e na ional Po ash Ins i u e and
E hiopian Minis y o Educa ion o unding he s udy. Deep app ecia ion is
exp essed o he Deb e Zei Ag icul u al Resea ch Cen e , E hiopia and Na u al
Resou ces Ins i u e, Finland o he p o ision o labo a o y acili ies. Since e
collabo a ion o he echnical assis an s du ing he labo a o y analyses is
g ea ly acknowledged. We would like o hank Samuel Feyissa o he map o
he s udy a ea. We a e also g a e ul o all a me s and de elopmen agen s
who pa icipa ed in he s udy.
Compe ing in e es s
The au ho s decla e ha hey ha e no compe ing in e es s.
Recei ed: 12 Ap il 2015 Accep ed: 13 Oc obe 2015
Re e ences
1. Amsalu A, S oosnijde L, G aa G. Long- e m dynamics in land esou ce
use and he d i ing o ces in he Be essa wa e shed, highlands o E hio-
pia. J En i on Manage. 2007;83:448–59.
2. Tsegaye G, Bekele W. Fa me s’ pe cep ions o land deg ada ion and de e -
minan s o ood secu i y a Bila e wa e shed, Sou he n E hiopia. E hio J
Appl Sci Technol. 2010;1:49–62.
3. Zeleke G, Hu ni H. Implica ions o land use and land co e dynamics o
moun ain esou ce deg ada ion in he No hwes e n E hiopian high-
lands. M Res De . 2000;22:184–91.
4. Ma son PA, Naylo R, O iz-Monas e io I. In eg a ion o en i onmen-
al, ag onomic, and economic aspec s o e ilize managemen . Sci.
1998;280:112–5.
5. Lakew D, Ca ucci V, As a W, Yi ayew A. Communi y based pa icipa o y
wa e shed de elopmen : a Guide line Minis y o ag icul u e and Ru al
De elopmen Addis Ababa, E hiopia. 2005. h p://ag iwa e pedia.in o/
images/ / e/Minis yAg icul u eE hiopiaCommuni yBasedWa e shed-
Managemen Guideline2005Pa 1A.pd . Accessed 3 Dec 2014.
6. Smaling EM, Nandwa SM, Janssen BH. Soil e ili y in A ica is a s ake. In:
Bu esh RJ, Sanchez PA, Calhoom F, edi o s. Replenishing soil e ili y in
A ica. Sol Sci Soc Am 1997. Vol 51. p. 47–61.
7. FAO (Food and Ag icul u e O ganiza ion). Soil e ili y managemen in
suppo o ood secu i y in Sub-Saha an A ica. Rome, I aly. 2001. p:// ao.
o g/agl/agll/docs/ oodsec.pd . Accessed 20 Jan 2015.
8. Sanchez PA. Soil e ili y and hunge in A ica. Sci. 2002;295:2010–9.
9. Haileselassie A, P iess JA, Veldkamp E, Teke ay D, Lesschen JP. Assessmen
o soil nu ien deple ion and i s spa ial a iabili y on smallholde s’ mixed
a ming sys ems in E hiopia using pa ial e sus ull nu ien balances.
Ag ic Ecosys En i on. 2005;108:1–16.
10. As aw B, Helu G, Yohannes U, Eylachew Z. E ec o c op esidues on g ain
yield o so ghum (So ghum bicolo ) o applica ion o N and P Fe ilize s.
Nu Cycl Agecosys. 1997;48:191–6.
11. Abebe M. Na u e and managemen o E hiopian soils. Eas Ha a ge,
E hiopia: Alemaya Uni e si y o Ag icul u e; 1998. p. 272.
12. Endale K. Fe ilize consump ion and ag icul u al p oduc i i y in E hiopia.
E hiopian De elopmen Resea ch Ins i u e wo king pape 003. 2011. p. 7.
13. Ju zi SC, Assamnew G, Haque I, Tedla A, As a ike A. In e media e echnol-
ogy o inc eased ood and eed p oduc ion om deep black clay soils
in he E hiopian highlands. In: P oceedings o FAO/SIDA semina on
inc eased ood p oduc ion h ough low cos ood c op echnology.
Ha a e, Zimbabwe. 1987. p. 373–83.
14. Debele B. The Ve isols o E hiopia: hei p ope ies, classi ica ion and
managemen . In: Fi h Mee ing o he Eas e n A ican Sub-Commi ee o
Page 9 o 10
Hailu e al. Ag ic & Food Secu (2015) 4:19
Soil Co ela ion and Land E alua ion, 5–10 Decembe 1983 Wad Medani,
Sudan. Wo ld Soil Resou ces Repo s No. 56. FAO (Food and Ag icul u e
O ganiza ion), Rome. 1985. p. 31–54.
15. Debele B. Managemen o Ve isols and ca chmen s ea men on
Delan a Dawun pla eau, No h Wollo p epa ed o Ox am–GB Addis
Ababa, May, 2000.
16. Beyene D. The esponse o pulse c ops o N and P e ilize s. In: Beyene
D, edi o . Wo kshop on e iew o soil science esea ch in E hiopia. Addis
Ababa, E hiopia, 11–14 Feb ua y 1986. IAR (Ins i u e o Ag icul u al
Resea ch), Addis Ababa, E hiopia. 1986; p. 87–91.
17. Ru he o d AS. B oad bed make echnology package inno a ions in
E hiopian a ming sys ems: an ex-pos impac assessmen . Resea ch
epo 20. ILRI (In e na ional Li es ock Resea ch Ins i u e), Nai obi, Kenya.
2008. p. 6–10.
18. Mamo T, Haque I, Kama a CS. Phospho us s a us o some E hiopian
highland Ve isols. In: Managemen o Ve isols in sub-Saha an A ica.
P oceedings o a con e ence held a In e na ional Li es ock Cen e o
A ica (ILCA), 31 Augus –4 Sep embe 1987 Addis Ababa, E hiopia. 1988.
p. 232–52.
19. Mamo T, Rich e C, Heilig ag B. Phospho us a ailabili y s udies on en
E hiopian Ve isols. JARTS. 2002;103:177–83.
20. E hioSIS (E hiopian Soil In o ma ion Sys em). 2015. h p://www.a a.go .
e /highligh ed-deli e ables/e hiopian-soil-in o ma ion-sys em-e hiosis/.
Accessed 15 Ma ch 2015.
21. Abunyewa A, Asiedu EK, Ahenko ah Y. Fe ilize phospho us ac ions
and hei a ailabili y o maize on di e en land o ms on a Ve isol in he
coas al Sa ana zone o Ghana. Wes A ican J Appl Ecol. 2004;5:63–73.
22. Ga y WH. A u u is ic iew o soil and plan analysis and nu ien ecom-
menda ions. Commun Soil Sci Plan Anal. 1998;29:11–4.
23. Ju zi SC, Abebe M. Imp o ed ag icul u al u iliza ion o Ve isols in he
E hiopian highlands an in e ins i u ional app oach. In: La ham M, Ahn P,
Ellio CR, edi o s. Managemen o Ve isols unde Semi-A id Condi ions.
P oceeding o he i s Regional Semina . IBSRAM, Bangkok. 1987. p.
173–83.
24. And eas P, Be nd -Micheal W. Soil sampling and s o age. In: Ma gesin R,
Schinne F, edi o s. Manual o soil analysis moni o ing and assessing soil
bio emedia ion. Sp inge -Ve lag: Be lin Heidelbe g; 2005. p. 3–13.
25. Gee GW, Baude JW. Pa icle Size Analysis. In: Klu e A, edi o . Me hods o
Soil Analysis. Ame ican Socie y o Ag onomy. 1986. Vol 7, p. 383–411.
26. Rhoades JD. In: Mille RH, Keeney DR, edi o s. Me hods o soil analysis.
Ame ican Socie y o Ag onomy. 1982. p. 539–79.
27. Black CA. Me hods o soil analysis. Ame ican Socie y o Ag onomy; 1965.
28. ISO (In e na ional O ganiza ion o S anda diza ion) 10694. Soil quali y-
De e mina ion o o ganic and o al ca bon a e d y combus ion
(elemen al analysis). 1995.
29. ISO (In e na ional O ganiza ion o S anda diza ion) 13878. Soil quali y-
De e mina ion o o al ni ogen con en by d y combus ion (elemen al
analysis). 1998.
30. Olsen SR, Cole CV, Wana abe FS, Dean LA. Es ima ion o a ailable
phospho us in soils by ex ac ion wi h sodium bica bona e. 1954. USDA
Ci cula , p. 939.
31. Williams CH, S einbe gs A. Soil sul u ac iona ions as chemical indices o
a ailable sul u in some Aus alian soils. Aus J Ag i Res. 1959;10:340–52.
32. Co enie A. Soil and plan es ing as a basis o e ilize ecommenda ions.
FAO soil bulle in 38/2. Food and Ag icul u e O ganiza ion o he Uni ed
Na ions, Rome, I aly. 1980.
33. Sol anpou PN, Schwab AP. A new soil es o simul aneous ex ac ion o
mac o and mic o-nu ien s in alkaline soils. Commun Soil Sci Plan Anal.
1977;8:195–207.
34. Mehlich A. Mehlich 3 Soil es ex ac an : a modi ica ion o he Mehlich 2
ex ac an . Commun Soil Sci Plan Anal. 1984;15:1409–16.
35. G igg JL. De e mina ion o he a ailable molybdenum o soils. J Sci Tech
N Zealand. 1953;30:405–14.
36. B emne JM, Mul aney CS. To al ni ogen. In: Page AL, Mille RH, edi-
o s. Me hods o soil analysis. Ame ican Socie y o Ag onomy. 1982. p.
595–624.
37. Jones JB J . Labo a o y guide o conduc ing soil es s and plan analysis.
2001. p. 227.
38. Kama a CS, Haque I, Beyene D. Cha ac e is ics o soils a he IAR esea ch
sub-cen es a Sheno and Ginchi. Addis Ababa: ILCA; 1989. p. 55.
39. Lemma G, Smi GN. Rela ionships be ween plan and soil nu ien s a us
and posi ion in he landscape on Pellic Ve isols o E hiopia. S A J Plan
Soil. 2008;25:119–26.
40. Tsegaye T. Ve isols o cen al highlands o E hiopia: Cha ac e iza ion and
e alua ion o he phospho us s a us. MSc Thesis Submi ed o he School
o G adua e S udies, Alemaya Uni e si y o Ag icul u e, Eas Ha a ge,
E hiopia. 1992.
41. Mu phy HF. A epo on e ili y s a us and o he da a on some soils o
E hiopia. Expe imen al S a ion Bulle in No. 44, Collage o Ag icul u e
HSIU. 1968. p. 551.
42. Taddese T. Soil, plan , wa e , e ilize , animal manu e and compos analy-
sis. Wo king Documen No. 13. In e na ional Li es ock Resea ch Cen e
o A ica, Addis Ababa, E hiopia. 1991.
43. Kebede F, Cha les Y. Soil e ili y s a us and Numass e ilize ecom-
menda ion o Typic Hapluus e es in he no he n highlands o E hiopia.
Wo ld Appl Sci J. 2009;6:1473–80.
44. FAO. Fe ilize s and hei use. 4 h ed. Rome: In e na ional Fe ilize Indus-
y Associa ion, FAO; 2000. p. 9–11.
45. Beyene D. Diagnosis o phospho us de iciency in E hiopian soils. In: Soil
Science Bulle in No.3. IAR (Ins i u e o Ag icul u e), Addis Ababa, E hiopia.
1982. p. 1–23.
46. Esayas A. Some physico-chemical cha ac e is ics o he Raya alley epo .
E hio J Na u al Reso . 2001;3:179–93.
47. Hazel on P, Mu phy B. In e p e ing soil es esul s: Wha do all he num-
be s mean? 2nd ed. CSIRO; 2007.
48. Landon JR. Booke opical soil manual: A hand book o soil su ey and
ag icul u al land e alua ion in he opics and sub opics. Essex: Longman
scien i ic and echnical; 1991.
49. Beyene D. Soil e ili y esea ch on some E hiopian Ve isols. In: Manage-
men o Ve isols in sub-Saha an A ica P oceedings o a con e ence
held a ILCA. 31 Augus –4 Sep embe 1987. ILCA (In e na ional Li es ock
Cen e o A ica), Addis Ababa, E hiopia. 1988. p. 223–31.
50. Finck A, Venka eswa lu J. Chemical p ope ies and managemen o Ve i-
sols. In: Ve isols and ice soils o he opics. 12 h In e na ional Cong ess
o Soil Science, New Delhi, India, Indian Socie y o Soil Science, New
Delhi, India. 1982. p. 61–9.
51. Mengel K, Ki kby EA. P inciples o plan nu i ion. Panima Publ. Co po a-
ion, New Delhi, Bangalo e, India. 1987. p. 6–103 (687).
52. Mamo T, Haque I. Phospho us s a us o some E hiopian soils, II. Fo ms
and dis ibu ion o ino ganic phospha es and hei ela ion o a ailable
phospho us. T op Ag ic. 1991;68:2–8.
53. Geb eselassie Y. Selec ed chemical and physical cha ac e is ics o soils o
Ade Resae ch Cen e and i s es ing si es in no hwes e n E hiopia. EJNR.
2002;4:199–215.
54. Negassa W, Geb ekidan H. Fo ms o phospho us and s a us o a ailable
mic onu ien s unde di e en land-use sys ems o Al isols in Bako a ea o
E hiopia. EJNR. 2003;5:17–37.
55. Lewis DC. Sul u . In: Pe e ill KI, Spa ow LA, Reu e DJ, edi o s. Soil analysis
an in e p e a ion manual. Collingwood: CSIRO Publishing; 1999. p. 221–8.
56. Sol anpou PN. Use o AB-DTPA soil es o e alua e elemen al a ailabili y
and oxici y. Commun Soil Sci Plan Anal. 1985;16:323–38.
57. Jones JB. Ag onomic Handbook: Managemen o c ops, soils, and hei
Fe ili y. Boca Ra on: CRC P ess LLC; 2003. p. 482.
58. Sims JT, Johnson CV. Mic onu ien soil es s. In: Mo ed JJ, Cox FR, Shu-
man LM, Welch RM, edi o s. Mic onu ien s in Ag icul u e. Book se ies No.
4. Madison: Soil Science Socie y o Ame ica; 1991. p. 427–76.
59. Shuman LM, Bandel VA, Donohue SJ, Isaac RA, Lippe RM, Sims JT,
Tucke MR, e al. Compa ison o Mehlich-1 and Mehlich-3 ex ac able soil
bo on wi h ho wa e ex ac able bo on. Commun Soil Sci Plan Anal.
1992;23:1–14.
60. Abbo TS. BCRI soil es ing me hods and in e p e a ion. Rydalme e: Bio-
logical and Chemical Resea ch Ins i u e, NSW Ag icul u e and Fishe ies;
1989.
61. Loide V. Abou he e ec o he con en s and a ios o soil’s a ailable
calcium, po assium and magnesium in liming o acid soils. Ag on Res.
2004;2:71–82.
62. Dobe mann A, Cassman KG, S a PC, C uz MA, Ad ien o, Pampolino MF,
e al. Fe ilize inpu s, nu ien balance, and soil nu ien -supplying powe
in in ensi e, i iga ed ice sys ems. II: E ec i e soil K-supplying capaci y.
Nu i Cycl Ag oecosys . 1996;46:11–21.