Lulseged	
  Tene1*,	
  Andrew	
  Sila2,	
  Job	
  Kihara3,	
  Gi<	
  Ndengu1,	
  Powell	
  Mponela1,	
  Keith	
  Shepherd2...
Source:	
  INED	
  
u SSA	
  countries	
  will	
  grow	
  the	
  fastest	
  –	
  pressure	
  on	
  
resources	
  
Backgro...
Background	
  
This	
  will	
  lead	
  to:	
  
	
  
	
  -­‐	
  ReducLon	
  in	
  farm	
  size	
  
-­‐  Expansion	
  to	
  ...
Input	
  (type,	
  diversity)	
  
ProducLvity	
  and	
  yield	
  
Cost	
  of	
  input	
  
Risk	
  
Background	
  
In	
  ar...
Evaluate	
  soil	
  nutrient	
  deficiency	
  levels	
  	
  
	
  
Assess	
  soil	
  health	
  status	
  and	
  its	
  spaLa...
Study	
  Area	
  and	
  Sites	
  
AfSIS	
  
CRP1.1	
  
Africa	
  RISING	
  
v  6	
  Countries	
  
v  29	
  Sites	
  
v ...
•  Take	
  advantage	
  of	
  data	
  collected	
  for	
  different	
  
projects	
  across	
  southern	
  Africa	
  
	
  
•...
Figure	
  (a)	
  Near-­‐infrared	
  spectrometer	
  and	
  (b)	
  raw	
  and	
  derivaLve	
  spectra	
  
used	
  to	
  cal...
Results	
  
(%)	
  
(mgkg-­‐1)	
  
(mgkg-­‐1)	
  
(mgkg-­‐1)	
  
(gkg-­‐1)	
  
(CmolcKg-­‐1)	
  
The	
  majority	
  of	
  the	
  sites	
  experience	
  low	
  soil	
  nutrient	
  content	
  
	
  
ü  All	
  sites	
  hav...
Total	
  N	
  (%)	
  
Results:	
  Prevalence	
  es3mates	
  and	
  cri3cal	
  limits	
  
Results:	
  Prevalence	
  es3mates	
  and	
  cri3cal	
  limits	
  
ApplicaLon	
  of	
  P	
  is	
  most	
  of	
  Malawian	
...
Results:	
  spa3al	
  variability	
  within	
  &	
  between	
  countries	
  &	
  sites	
  
In	
  addiLon	
  to	
  the	
  o...
EsLmate	
  gap	
  between	
  current	
  soil	
  nutrient	
  status	
  in	
  relaLon	
  
to	
  maize	
  nutrient	
  require...
Approximate	
  cost	
  required	
  to	
  replenish	
  the	
  observed	
  gap	
  
Depending	
  on	
  countries	
  and	
  ho...
Considering	
  the	
  
limited	
  income	
  of	
  
smallholders	
  and	
  the	
  
vulnerability	
  of	
  
agriculture	
  t...
Results:	
  Overall	
  cost	
  of	
  input	
  N	
  and	
  P	
  input	
  to	
  replenish	
  gap	
  
Alterna3ves	
  such	
  ...
Conclusion	
  
	
  
ü  Evidences	
  show	
  that	
  key	
  nutrients	
  are	
  limiLng	
  in	
  SSA	
  
ü  Input	
  use	...
Soil Health in Southern Africa and implications on sustainable intensification 2014 L Desta et al
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Soil Health in Southern Africa and implications on sustainable intensification: How much is the gap? World Congress Soil Science 2014 L Desta et al

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Soil Health in Southern Africa and implications on sustainable intensification 2014 L Desta et al

  1. 1. Lulseged  Tene1*,  Andrew  Sila2,  Job  Kihara3,  Gi<  Ndengu1,  Powell  Mponela1,  Keith  Shepherd2,   Markus  Walsh4  and   Deborah  Bossio3   www.ciat.cgiar.org   Eco-­‐Efficient  Agriculture  for  the  Poor   Soil  health  in  Southern  Africa  and   implica3on  on  sustainable  intensifica3on:   how  much  is  the  gap?   Lulseged  Tamene1,  Andrew  Sila2,  Job  Kihara1,  Gi<  Ndengu1,   Powell  Mponela1,  Keith  Shepherd2,  Markus  Walsh3  and   Deborah  Bossio1   1CInternaLonal  Center  for  Tropical  Agriculture,  2World  Agroforestry  Center,  3CThe  Earth  InsLtute     20th  World  Congress  of  Soil  Science   June  8-­‐13,  2014,  Jeju.  Korea  
  2. 2. Source:  INED   u SSA  countries  will  grow  the  fastest  –  pressure  on   resources   Background   PopulaLon  increase  
  3. 3. Background   This  will  lead  to:      -­‐  ReducLon  in  farm  size   -­‐  Expansion  to  steep   slopes  and  marginal   areas     -­‐  More  degradaLon   -­‐  Low  yield     There  is  a  need  to  produce   more  from  small  areas     Sustainable   IntensificaLon  
  4. 4. Input  (type,  diversity)   ProducLvity  and  yield   Cost  of  input   Risk   Background   In  areas  low  income   households  and   high  environmental   risk,  implemenLng   sustainable   intensificaLon  may   be  a  challenge  
  5. 5. Evaluate  soil  nutrient  deficiency  levels       Assess  soil  health  status  and  its  spaLal   variability       Gain  preliminary  picture  of  the  ‘gap’  that  should   be  replenished  to  improve  soil  health  and   achieve  “sustainable  intensificaLon”     Suggest  possible  opLons  to  enhance  sustainable   intensificaLon  under  prevailing  SSA  smallholder   circumstances   Objec3ves  
  6. 6. Study  Area  and  Sites   AfSIS   CRP1.1   Africa  RISING   v  6  Countries   v  29  Sites   v  464  Clusters   v  4640  Plots   v  18560  Sub-­‐plots   v  9280  soil  samples   Study  focuses  in  six  countries  of  Southern  Africa  
  7. 7. •  Take  advantage  of  data  collected  for  different   projects  across  southern  Africa     •  Soil  and  landscape  aeributes  data  collected  based   on  spaLally  straLfied  random  sampling  approach   Approaches   Sub-plot = 0.01 ha Site = 100 km2 Cluster = 1 km2 Plot = 0.1 ha Sub-plot = 0.01 ha Site = 100 km2 Cluster = 1 km2 Plot = 0.1 ha 0.01  ha   Site = 100 km2 Cluster = 1 km2 Site = 100 km2 Cluster = 1 km2 Plot = 0.1 ha Sub-plot=0.01ha Site=100km2 Cluster=1km2 Plot=0.1ha Sub-plot=0.01ha Site=100km2 Cluster=1km2 Plot=0.1ha
  8. 8. Figure  (a)  Near-­‐infrared  spectrometer  and  (b)  raw  and  derivaLve  spectra   used  to  calibrate  predicLon  models   Approaches   ² Over  9000  top-­‐  an  sub-­‐   soil  samples     ² NIR/MIR  spectral   analysis   ² 10-­‐20%  wet  chemistry   data  for  calibraLon  
  9. 9. Results   (%)   (mgkg-­‐1)   (mgkg-­‐1)   (mgkg-­‐1)   (gkg-­‐1)   (CmolcKg-­‐1)  
  10. 10. The  majority  of  the  sites  experience  low  soil  nutrient  content     ü  All  sites  have  zinc  limitaLon     ü  About  95%  of  the  sites  suffer  from  nitrogen  deficiency     ü  70%  of  the  sites  are  phosphorus  deficient     ü  65%  of  soils  have  poor  soil  structure     ü  About  40%  of  the  sites  have  low  potassium  level     ü  About  40%  of  the  sites  have  poor  SOC     q Overall  soil  ferLlity  status  is  beeer  in  Malawi   Results:  overall  soil  condiLon      
  11. 11. Total  N  (%)   Results:  Prevalence  es3mates  and  cri3cal  limits  
  12. 12. Results:  Prevalence  es3mates  and  cri3cal  limits   ApplicaLon  of  P  is  most  of  Malawian  soils   may  not  be  effecLve  –  even  it  may  lead  to   environmental  risk  due  to  P  leaching  into   water  bodies?   P  (mg  kg-­‐1)  
  13. 13. Results:  spa3al  variability  within  &  between  countries  &  sites   In  addiLon  to  the  observed  gap,   there  spaLal  variability  at  site,   cluster,  plot  levels     Example  K  for  one  site  and  cluster   in  Botswana   Country:  Botswana   Site:  Shoshong     Country:  Botswana   Site:  Shoshong   Cluster:  9  (variability  within  a  cluster,   between  plots     Cluster   Plot   ImplicaLon  on  ferLlizer   recommendaLon:  fine-­‐tune   to  local  soil  condiLons  
  14. 14. EsLmate  gap  between  current  soil  nutrient  status  in  relaLon   to  maize  nutrient  requirement   Ø  N  (114  kg  ha-­‐1)  and  P  (17  kg  ha-­‐1)  show  the  ‘widest’  gap  for   maize  producLon     Ø  Botswana  followed  by  Mozambique  show  large  N  gap     Ø  Malawi  and  Zimbabwe  low  (113  kg-­‐ha-­‐1)  N  gap       Ø  Botswana  (30  kg  ha-­‐1)  followed  by  Angola  (27  kg  ha-­‐1)   widest  P  gap     Ø  Malawi  has  no  P  gap  –  subsidy?     Results:  gaps  in  relaLon  to  maize  nutrient  requirements  
  15. 15. Approximate  cost  required  to  replenish  the  observed  gap   Depending  on  countries  and  household  status,   farmers  may  be  able  to  pay  for  ferLlizer  but  not  to   fill  the  whole  ‘gap’   Results:  Overall  cost  of  input  N  and  P  input  to  replenish  gap   0   50   100   150   200   250   Angola   Botswana   Malawi   Mozambique   Zambia   Zimbabwe   Cost  of  nutrient  (US$  per  ha)   Nitrogen   Phosphorus  
  16. 16. Considering  the   limited  income  of   smallholders  and  the   vulnerability  of   agriculture  to   different  kinds  of   stresses,  it  maybe   difficult  for  some   farmers  to  fill  the   ‘gap’  with  ferLlizer   input.         q AlternaLve  opLons   needed     Households  ordered  by  their  total  annual  income  (USD$)   Total  annual  income  ($USD)   Results:  Overall  cost  of  input  N  and  P  input  to  replenish  gap  
  17. 17. Results:  Overall  cost  of  input  N  and  P  input  to  replenish  gap   Alterna3ves  such  as  organic  inputs,  intercropping,  fer3lizer   crops,  CA  can  help  supplement  inorganic  input     Need  to  ‘encourage’  farmers  to  use  those  op3ons!   Supplement  with:  credit,  insurance,  subsidy,  …  
  18. 18. Conclusion     ü  Evidences  show  that  key  nutrients  are  limiLng  in  SSA   ü  Input  use  is  low  and  generally  ‘blanket’  approach  is  used   ü  ‘Site-­‐specific’  informaLon  needed  to  guide  implemenLng   targeted  intervenLon     ü  Price  of  ferLlizer  is  high  (8X  where  it  is  sourced  from)  –   encourage  and  enhance  local  producLon,  reduce  tax,   improve  complementary  inputs  +  ’green  opLons’   ü  Farmers  have  limited  ‘economic’  capacity  and  knowledge   to  use  adequate  input  sustainably:  incenLves,  credit  facility     ü  Farmers  contemplate  technology  use  –  risk  aversion.   Insurance,  subsidy,  Lmely  informaLon  

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