1. 1 In field Rainwater Harvesting for Improved Maize Production (Synthesis Results – Lessons & Challenges) By Mário Chilundo & Paiva Munguambe UEM-FAEF Final Scientific Workshop JHB, 15-18 th June 2009

2. 2 Main Objective of the trials Increase water availability for crop growth though in field water harvesting technique

3. RWH principle 3

4. RWH principle… Chókwè

5. Semi-Arid region October to March: rainy season with 75 % of the annual rain; April to September: dry season with 25 % of the annual rain. Chókwè’s average annual rainfall: 582.0 mm Introduction…Introduction…

6. 6 Balanço hídrico (Pr-ETc) Water balance (Pr-ETc)

7. 7 Study area Chókwè

8. Methodology On station trials (EAC) Design: RCBD Crop: Maize (Matuba: 120 days; Potential yield: 5-6 ton/ha) Seasons (2006/07; 2007/08 and 2008/9) Mulch: 20 ton/ha (vegetable residues) Rain gauge: Precipitation Parameters: plant height and grain yield

9. RWT principle RWT: Catchment area covered by PVC plastic Ratio: control S80 (80*30 cm; 1:1); S160 (160*30 cm; 1:2) and S240 (240*30 cm; 1:3) – 8 rows/plot (6 effectives+ 2 border) Cropping Area (CA) 80X30 cm Catchment Area (CTA) 160X30 cm Ratio (CTA/CA) = 2:1 Plastic cover

10. Trials…

11. Maize grain yield (ton/ha) 11 a a B A b C 2007/08 Total of 392 mm 2008/09 Total of 471.1 mm

12. 12 Results (WUE – Water Productivity)

13. Estimated Costs (500 m 2 plot) 13 QuantityCosts (USD) ActivityUnity Control (1:1) T2 (2:1)T3 (3:1) Control (1:1) T2 (2:1)T3 (3:1) PVC Plasticm-204156-306312 Seedskg20.50.320.50.3 SowingUnity11115105 WeedingUnity3114515 Total 62.0331.5332.3

14. 14  Ratios 1:2 (S160) and 1:3 (S240) increased water availability for the crop, resulting in higher grain yields per plant and thus increase WUE;  Climate change vs rainfall patterns vs sowing dates need to be addressed because they will have impact on the yields;  Need to test other “local” material as alternative due to high investments costs (plastic) ;  Need to consider IPDM and fertilizers to increase water productivity and yields Final remarks/challenges

15. 15 OBRIGADO