1. Conservation Agriculture (CA) in Southern Africa: Longer term trends in soil quality and crop productivity By Christian Thierfelder and Isaiah Nyagumbo In collaboration with: Amos Ngwira, Ivy Ligowe, Sebastiao Famba, Ivan Cuvaca, Mwangala Sitali, Tobias Charakupa, Herbert Chipara and Sign Phiri

2. IntroductionIntroduction  Unreliable climatic conditions (drought)  Challenging soils  Increased physical, chemical and biological soil degradation  Reliance on maize as staple food crop Environmental situation in southern Africa: A possible solution:  Sustainable crop intensification through Conservation Agriculture (CA) ……. …. BUT widespread promotion of CA in southern Africa without scientific base has also provoked a lot of critique!

3. Trial Locations in Southern Africa:  Henderson Research Station, Zimbabwe (since 2004/05), 884 mm average rainfall  Farmers Training Center, Monze, Zambia (since 2005/06), 748 mm average rainfall  Sussundenga Research Station, Chimoio, Mozambique (since 2006/07), 1155 mm average rainfall  Chitedze Research Station, Lilongwe, Malawi (since 2007/08), 920 mm average rainfall

4. Treatments to focus on:

5. Magoye ripper Basin planting Fitarelli jab- planter AT Direct seeder Dibble stick

6. Results from the LT trials Three phases of a crop rotation (Maize- Cotton-Sunnhemp) in Monze, Zambia

7. Sussundenga Monze Chitedze InfiltrationInfiltration Henderson

8. Cumulative soil erosion from 2005-2011

9. Soil moisture in 0-60cm, Henderson, Zimbabwe, 2009/2010

10. Soil moisture in 0-60cm, Monze, Zambia, 2009/2010

11. Effect of treatments on soil organic carbon in the CA LT trial in Monze FTC. 0-30 cm, Zambia, October 2005 and 2008.

12. Aggregate stability (%) at Monze FTC, 2009

13. Summary of maize grain yield at Henderson, Zimbabwe, 2005-2011

14. Summary of maize grain yield at Monze FTC, Zambia, 2006-2011

15. Summary of maize grain yield at Sussundenga, Mozambique, 2007-2011

16. Summary of maize grain yield at Chitedze, Malawi, 2007-2011

17. ConclusionsConclusions  CA offers many opportunities for farmers in southern Africa  Results from LT trials show:  higher infiltration,  lower soil erosion,  higher soil moisture,  Increased carbon and aggregate stability  Higher crop performance in the longer term  Benefits of CA emerge over time  Rotations play a significant role in CA cropping systems

18. ConclusionsConclusions  More socio-economic and biophysical studies are needed to understand and overcome those challenges  The CA trials are the only source of scientific longer term data in southern Africa….. …..they need to be supported (financially) and used effectively (by science)…...!  Promoting CA in southern Africa has challenges:  Residue retention  Rotations  Weed control  Mindset

19. Thank you very much for your attention! CA long-term trial at the Monze Farmer Training Centre, Zambia