CPWF PN 17 Workshop, Johannesburg, South Africa 15-18 June 2009

1. Biophysical and socio-economic factors affecting the use of in-situ water harvesting technologies in the semi arid Limpopo Basin: Experiences from Gwanda district, Zimbabwe CPWF PN 17 Workshop, Johannesburg, South Africa 15-18 June 2009 I. Nyagumbo, M. Munamati, E. Chikwari and D. Gumbo Department of Soil Science and Agricultural Engineering University of Zimbabwe e-mail: inyagumbo@agric.uz.ac.zw

2. 1. Introduction In-situ water harvesting structures have been promoted in Southern Africa as a solution to drought mitigation in semi-arid regions and are an option to improved agricultural water management by resource constrained smallholder farmers.

3. Increasing yields Options for improved agricultural water management Hi- tech irrigation Techns Eg drip Costly Supplementary irrigation technologies eg wetlands, surface irrigation Upper limit for shf without capital In-situ water conservation & harvesting technologies e.g. dead level contours, fanya juus, CA tied ridging/ furrows Options for blue water productivity Use of organic and inorganic fertilizers Use of improved seed eg hybrids Options for improving green water productivity in rainfed systems Increasing investment costs

4. 1. Introduction continued In several situations the standard graded mechanical conservation structures such as contour ridges have been found to be inappropriate due to excessive run-off disposal Promotion by NGOs and others particularly in Zimbabwe, has tended to be indescriminate i.e All soil types (texture, soil depth)? Topographic conditions? Rainfall conditions? All farmers? In Gwanda various organizations such as Practical Action, ORAP, ICRISAT and World Vision have promoted their use Not much is known about their effectiveness in terms of water conservation and drought mitigation. No hard data!

5. 1. Introduction continued However various options have developed in the last decade eg dead level contours with infiltration pits, fanya juus, deepened contours etc. The systems require extra labour compared to standard contours. Can we justify these huge labour investments by farmers! Could we probably fine tune recommendations for use of such structures?

6. 1. Fanya juu contour (Chivi, Zim) • Structures placed at • horizontal intervals of • 20-30 m depending on slopes • Bank on upper side of slope • May be graded or on true contour

7. 2. Deepened contours can help to reduce the rate of disposal of excess water Zvishavane, Southern Zimbabwe

8. 3. Infiltration Pits dug along a standard contour ridge channel Contour bank Buhera, Manicaland, Zimbabwe Infiltration pit

9. 4. Dead level contours reinforced with covered infiltration pits

10. Farmers believe covering the pits can help to reduce evaporation water losses! But there is no quantitative data to support this view….!

11. 2. Study Objectives To explore biophysical conditions (soil type, depth, slope and topographic conditions) that characterise successful in-situ water harvesting To explore preconditions for success based on farmers experiences Refine recommendations for applying in-situ WH systems so as to justify scarce labour investments.

12. 3. Methodology Study carried out in Gwanda district of Zimbabwe (Mat South Province). Key partners: Gwanda Rural District Council, Practical Action, Agritex, students Studies carried out in Wards 17 & 18 of Gwanda district

13. 3. Methodology Meetings held at ward centres with farmers and community leaders Key informants identified Farmers classified into 3 groups by own peers through group work by village Very successful Medium Poor performers

14. 3. Methodology 1. Key informant survey: 14 respondents (general constraints and factors, information about users of in-situ WH farmers or respondents 2. Formal survey (55 respondents): socioeconomic characteristics 3. Biophysical survey: 14 sites investigated detailed soil studies of sites : Soil texture, depth, drainage, existence of impermeable bed rock, slopes

15. 3. Classification into Resource Categories Calculation of resource status • Respondents were classified into 3 resource categories (wealthy, medium rich, resource constrained) based on 3 criteria • Range of implement types • livestock value, • land size. Livestock value • Market prices of livestock prevailing at time of study were used in the formula (300D+250C+20G+5P)/575T where • figure is price in USD, • D = number of donkeys, C= number of cattle, G= number of goats, P= number of poultry owned per hhd, • T is total price of individual livestock types • Range of Implement types referred to the different types of implements owned • The values from the 3 criteria were then used to classify the respondents into 3 groups.

16. 3. Methodology cont’d Relationships between performance of WHT and the following factors were investigated; Sex Resource status Land size Field location Labour numbers Age Experience Data analysed using various SPSS statistical tools on the 55 respondents data

17. 4. RESULTS

18. Biophysical issues

19. 4.1 Perceptions of key informants on WHTs Dead level contours with pits perceived to be most effective (72%)

20. 4.2 Location and Slopes of WHT fields • Field Location: 50% key informants considered location as unimportant, 36 % =>homestead fields, 21 % =>far fields. Stats (N=55) showed insignificant correlation bwt success and location of fields. So location was not an important success factor! • Slope did not seem to matter much (all slopes studied <4%) .However 64 % key informt farmers felt gentle to moderate slopes were prime. Stats based on a small sample of 14 analysed sites suggested slope was insignificant.

21. 4.3 Area of WHT fields and relationship with total arable area • A significant linear relationship betwn total arable area and area under WHT (p = 0.000, r=0.84) , see figure below • The bigger the arable area the bigger the proportion put to WHT

22. Relationship between total arable area and that under WHTs (ha)

23. Resource status vs Total arable and Area under WHT • Resource status significantly influenced total arable area (p=0.000) and that put to WHT (p=0.001). Wealthy farmers had the highest total arable area followed by medium rich and lastly resource constrained farmers • Avg area WHT=1.83 ha • Avg total area= 4.49 ha

24. 4.4 Effects of soil types

25. 4.4 Effects of Soil types • Most of the best farmers had heavier textured soils while the poor farmers had light textured soils. 83 % of the respondents key inf. felt deep soils were more effective. • Shallow depth <60 cm also characterized the poor performers while deep soils >70 cm were more apparent among successful farmers. N.B.The existence of a slightly indurated parent material seems to enhance the bucket effect but at the same time allowing drainage to take place in excessively wet periods!

26. Socio-economic issues

27. 4.5 Resource status vs Perfomance • Generally there is significant correlation between performance and resource status, at p=0.004 • Within the wealthy category,42.1% are successful, while 14.3% and 13.8% are average and poor performers respectively • Within the medium rich category, the majority were average performers(57.1%) compared to 42.1% and 34.1% successful and poor performers respectively • Reason; innovative, capitalise on new opportunities to acquire knowledge and other resources accessible within the community • Within the resource constrained category, the majority (75.0% ) were poor performers • Results suggest that wealth status contributes to success or failure in use of WHT • Medium wealthy people could be best bet investment targets for technology! Drivers of change

28. 4.6 Links between performance and sex Sex vs Perfomance • Performance rating was significantly correlated (p=0.007) to sex of household head. • Eg Within the most successful group 94.7 % were men compared to 5.3 % women • In the average performance category, 71.4% men and 28.6% women • Within sex, 82.4% of women were poor performers compared to 17.6 % in the other categoriess. Only 39.5% men were in the poor cat. N.B Widows, hhd with absent husbands disadvantaged, targeting?

29. 4.7 Correlation btw sex and resource status Sex vs Resource status • Sig Pearson correlation between resource status and sex (p=0.039). • Within the wealthy category, 69.2% of respondents were men compared to 30.8% women. • In the medium rich category 86.4 % were men compared to 13.6% women. • Within sex category most women (58.8%) were resource constrained compared to men (26.3%)

30. 4.8 Does experience have anything to do with performance? Experience vs Perfomance • No significant difference in mean years of experience across performance ratings, • Although data tended to show a decline in performance with decrease in number of years. • Increasing experience also tended to reflect increase in performance

31. 4.9 Labour and resource status/ performance • No significant difference between labour numbers and performance and resource status. Avg per household=6.3 (n=55). However, the majority (93% KI) of the farmers felt labour was a key factor for success.

32. 4.10 Other issues • The most successful farmers had made modifications to their systems which included: plastering the bottom of pits, covering the pits to reduce evaporation, altering the depth etc. • Education and social status did not have any bearing on performance • A sig. difference (p<0.05) in age between successful and poor performers with the elderly being more successful. • Average age was 51 years

33. 5. Any Conclusions? Performance of WHTs dependent on soil type: Best performance is obtainable from deep, heavy textured soils with some underlying semi-permeable bedrock There was no apparent preference in allocation of land for WHTs between homestead and far fields. Slope had no apparent effects but could be because study area had limited slope ranges The proportion of land under WHTs increased with land ownership and so well resource farmers had more choices.

34. 5. Conclusions Resource ownership could be a key factor in farmers ability to scale out WHTs. Performance was significantly linked to resource status. Medium wealthy people could be best bet investment targets for technology! Women headed households were performing rather poorly in WHTs suggesting the need for special attention to gender in the promotion of WHTs The influence of labour on performance was not apparent from the study (methodological limitations!) Resource ownership could be a key factor in farmers ability to scale out WHTs. Performance was significantly linked to resource status. Women headed households were performing rather poorly in WHTs suggesting the need for special attention to gender in the promotion of WHTs Sex, labour and land size are also key factors Performance of WHTs dependent on soil type: Best performance is obtainable from deep, heavy textured soils with some underlying semi-permeable bedrock Study area had limited slopes and so slope had no apparent effects

35. 6. Next Step! Use of GIS tools and Remotely sensed data to assess historical performance of WHTs still to be done but limited by resources There is need for more resources for more in-depth studies to demystify performance variation across locations and conditions particularly in Phase 2! Department has the zeal!

36. Thanks!!