1. Design of direct seeding mulch based cropping systems (DMC) for sustainable Maize production in Cambodia General Directorate of Agriculture Ministry of Agriculture, Forestry and Fishery Second conference on Conservation Agriculture in South East Asia July, 7 th 2011 - Royal University of Agriculture - Phnom Penh – Cambodia Boulakia S., Kou P., Leng V., Sar V., Chabierski S., Sona S., & Séguy L.

2. Maize and Cassava, the crops of Pioneers

3. 3 main Pilot Zones 2004 2 1 3 2009 Localization of the main PADAC ’ s R&D areas A multi-regions “ on farm, with and for farmers ” research sites 1/ Kampong Cham - Dambe / Ponhea Krek Cassava production area with smallholders – “ Verti-oxysol ” on basalt 2/ Kampong Cham – Chamcar Loeu Divers. crop.  (Soy., Corn, Cass. & Perennial) – Red oxysol on basalt 3/ Battambang – Rattanak Mondul (Stabilized Pioneer front of 90 ’ s) Corn (+ Cass.) production area with small /medium farms – Vertisol on limestone

4. 1/ Sesame Soybean 2/Cassava Monoculture 3/ MaizeMaize MarsAvrilMaiJuinJuilletAoûtSept.Octob.Nov.Dec. disc Main Plow based cropping systems (Farmers ’ references) DMC with Maize as diversification crops in Kampong Cham disc DMC to escape from Maize mono-cropping in Battambang

6. Year n heavy rains"scattered" rains Aug.JulyJuneMayAprilMar.Dec.Nov.Octo.Sept.Jan.Fev. heavy rains"scattered" rains Aug.JulyJuneMayAprilMar.Dec.Nov.Octo.Sept.Jan.Fev. Year n+1 Stylo + B. p MilSoybean mc Sorgho + Stylo Stylo.Stylo +Sorgho regrow Maize + Stylo. Principle DMC systems designed by R & D Maize x Soybean production Maize + Stylo. Stylo. Maize + Stylo. Stylo. Maize “mono cropping”Maize // Soybean rotation

8. Principle DMC systems for Maize x Soybean Results on Matrix of cropping systems

9. Maize + Brachiaria ruziziensis Maize + Stylosanthes guianensis Principle DMC systems for Maize x Soybean Results on Matrix of cropping systems

11. Principle DMC systems for Maize x Soybean Results on Demonstration plots

12. Principle DMC systems for Maize x Soybean Results on Demonstration plots

13. Problem in Battambang on Vertisol  New CC Stylo + V. umbellata, Stylo + Cajanus c, Stylo + C. juncea Stylo. + Cajanus c. Stylo. + V. umbellataStylo. + Sorghum Principle DMC systems for Maize x Soybean Specific case of Vertisol in Western regions

15. Principle DMC systems for Maize x Soybean Results on Pilot extension network

16. Principle DMC systems for Maize x Soybean Economic performance

17. Principle DMC systems for Maize x Soybean Economic performance Economic threshold on F1: 6,5 t/ha of Corn # 3 t/ha of Soybean  Intro of high value crops at defoliation: “ Chea ”, Sunflower

18. Year n heavy rains"scattered" rains Aug.JulyJuneMayAprilMar.Dec.Nov.Octo.Sept.Jan.Fev. heavy rains"scattered" rains Aug.JulyJuneMayAprilMar.Dec.Nov.Octo.Sept.Jan.Fev. Year n+1 Cassava “mono cropping” Cassava + Stylo. Stylo. Cassava + Stylo. Cassava // Maize rotation Cassava + Stylo. Stylo. Maize + Stylo. Active growth of the Bio-pump lc Principle DMC systems designed by R & D Maize x Cassava production

20. Intro. of Chisel “ Strip tillage ” Principle DMC systems for Maize x Cassava Results on Matrix of cropping systems

21. Principle DMC systems for Maize x Cassava Results on Matrix of cropping systems

23. Intro. of Chisel “ Strip tillage ” Principle DMC systems for Maize x Cassava Results on Demonstration plots

24. Principle DMC systems for Maize x Cassava Results on Demonstration plots

26. Construction of DMC based cropping systems for upland rainfed agro-ecosystems After 6 years evolution, principle DMC systems promoted by PADAC Project Performance Cassava « DMC » Farmers 2009, 2010 x Year 1-2-3 Performance Maize Farmer – Maize as security 1/ price & 2/ early climate accident on Cassava … Stylo in Cassava difficult between 0 and fierce competition … V. unguiculata cc or V. radiata + Stylo (safety on early climate irregularity)

27. Construction of DMC based cropping systems for upland rainfed agro-ecosystems Traditional Plow based Cassava cropping system Huge and unpredictable inter-annual prices ’ variations Profit margin > 1 200 USD /haProfit margin < 0 USD /haProfit margin > 1 800 USD /ha

28. Construction of DMC based cropping systems for upland rainfed agro-ecosystems Economic performances of traditional Plow based system for Cassava production …  In 2011, farmers refused annual rotation with any other crop !!!!

29. Conclusion … Orientation of the next steps for cropping systems design Species diversity: - a request for agro-technical sustainability - to improve ecological intensification - to face the “ short-termist ” simplification under the “ market hammer ” 2 Maize (or 1 Maize and 1 Sunflower) & 1 Cassava in 2 years combined with suppression of the strip tillage … 6-7 sp. in 2 years rotation Cassava // Maize - Maize rotation Cassava + V. radiata Stylo. Maize + El. + C. juncea Year n heavy rains"scattered" rains Aug.JulyJuneMayAprilMar.Dec.Nov.Octo.Sept.Jan.Fev. heavy rains"scattered" rains Aug.JulyJuneMayAprilMar.Dec.Nov.Octo.Sept.Jan.Fev. Year n+1 Maize + Stylo.