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An investigation of tillage systems and implement design for water conservation in semi arid conditions in Botswana

By Elias Kethobile

Abstract

Botswana, as a semi arid country, is faced with serious shortage of moisture for crop production. Its challenging climatic condition makes the little moisture received from summer rainfall insufficient. The development of appropriate tillage systems can assist with sustainable crop production. The aim of this project was to come up with a tillage system to improve the suitability of the physical conditions of soil for effective seeding in rain fed farming in Botswana. Strip, Reservoir (depression) and no tillage systems (control) were therefore investigated. Laboratory investigation of the tillage systems for soil water conservation and erosion was undertaken under different slopes (5 and 10°) and rainfall intensities (55 and 95 mm/hr). Energy requirements and work rates of the systems were analysed. The results showed that slope has effects on the capability of strip tillage to harvest water from rainfall of low intensity. It managed to harvest 69.12% of rainfall from 55mm/hr rainfall at a slope of 5° whereas at 10°slope it harvested about 49%. The effects of slope were not significant for the reservoir tillage and no tillage systems. Under a higher intensity rainfall of 95mm/hr the effects of slope were insignificant. The only source of variance was due soil disturbances and the strip soil disturbance performed better than the other treatments. When eroded soil was investigated under low intensity rainfall (55 mm/hr), there was no significant difference between strip and depression. Depression and strip soil disturbances reduced soil erosion similarly by 47 and 46 % respectively. Under high intensity rainfall eroded soil was still high under undisturbed soil disturbance. This is due to the fact that when the soil surface is bare, there is a higher risk of soil erosion. But when strips and depression are created, the risk of soil erosion is localised especially at high rainfall intensities. The evaporation analysis showed no significant difference among the tillage systems. This means that the power of water conservation in semi arid environment lies more on water harvesting than reduction of evaporation.The analysis of power and work rates showed big advantage of strip tillage system over reservoir tillage in the sense that it required less energy and power to complete a hectare of land. Its work rate is almost double of strip tillage. From the results it can be concluded that, at low slope and low rainfall intensity strip tillage harvest more water than reservoir tillage and zero tillage systems. When slope is elevated there is no difference between strip and reservoir tillage. The strip tillage system harvest more water than both reservoir tillage and zero tillage at high intensities. Strip and reservoir tillage reduce soil erosion similarly at both low rainfall and high rainfall intensity. The energy requirements and work rate were more positive for strip tillage that reservoir tillage. Therefore with these results a conceptual design of strip tillage system was developed

Publisher: National Soil Resources Institute
Year: 2006
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/1383
Provided by: Cranfield CERES

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Citations

  1. (2005). 2005).Single tine forces.
  2. (2003). A New Reservoir Tillage System for Crop Production in Semiarid Areas. doi
  3. A.(1979) Water Transport Through Soil, Plant, and Atmosphere. In doi
  4. (1990). Agricultural engineering in development tillage for crop production in areas of low rainfall.
  5. (1984). Agroclimatological data for Africa = Données agroclimatologiques pour l'Afrique. 2: Food and Agriculture Organization of the United Nations,
  6. (1982). An investigation into cultivation methods for dry land farming in semi-arid regions with summer rainfall.
  7. (1998). An investigation into soil management and implement design for water conservation in dry farming systems. PHD thesis,
  8. (1979). Ancient Agricultural Systems in Dry regions. In doi
  9. (1990). and trickle doi
  10. (2006). Application and Assessment of Precision Deep Tillage. doi
  11. (2006). Application of reduced tillage in hills in Central Nepal. doi
  12. (1992). Applied Soil Physics. doi
  13. (1989). Bare soil evaporation. MSc thesis,
  14. (1988). Choosing and Using farm machines.
  15. (2000). Conditions and Infiltration Distribution in a Small Watershed in the Loess Area of China. In
  16. (1999). Conservation tillage in U.S. agriculture: environmental, economic and policy issues. doi
  17. (1983). Conservation: Central Great Plains. doi
  18. (1993). Crop Production in the West African Dry lands.
  19. (1979). Development of Present Dryland Farming Systems. In doi
  20. (1993). Dryland Farming in Africa.
  21. (2006). Effects of tillage and mode of straw mulch application on soil erosion in subcutaneous tract of Punjab, doi
  22. (2006). Effects of tillage and mulching on runoff under banana (Musa spp.) on a tropical Andosol. doi
  23. (1988). Engineering design: a systematic approach. Design Council Parsons, N. Botswana history pages.
  24. (1993). Engineering Principles of Agricultural machines. doi
  25. (1993). Field measurement of soil erosion and runoff. FAO Soils Bulletin 68. Rome, FAO. ___________________________________________________________________ Elias Kethobile
  26. (2000). Final Report, Volume 1, Main Report. Tahal Consulting Engineers LTD, Ministry of Agriculture,
  27. (2006). Hydraulic conductivity, residue cover and soil surface roughness under different tillage systems in semi - arid conditions. doi
  28. (1983). Introduction. In
  29. (2003). Ngoro: An indigenous, sustainable and profitable soil, water and nutrient conservation system in Tanzania for sloping land. doi
  30. (1993). of machine operation:
  31. (1992). of machine operation: Planting. 3 rd edition Illinois, Deere and Company service Training.
  32. (1980). of Soil Physics. doi
  33. (1993). Principles of Dryland Farming. In Rowland J.R.J. Dryland Farming in Africa.
  34. (1978). Principles of farm machinery. Avi Pblishing Co. doi
  35. (2005). Principles of hydrology.
  36. (2005). Reservoir tillage for semi-arid environments. doi
  37. (2006). resources in the savanna regions of Boswana. Geography department
  38. (1994). Soil Hydrology. doi
  39. (1979). Soil management in semi-arid environments: their definition and distribution. In doi
  40. (1988). Soil Physics. doi
  41. (2006). Soil porosity and water infiltration as influenced by tillage methods. doi
  42. (2005). Strip tillage effect on seed bed soil temperature and other soil physical properties. doi
  43. (2002). Strip tillage for 'No till' row crop production. Applied ___________________________________________________________________ Elias Kethobile doi
  44. (2003). The conservation and improvement of sloping land: a manual of soil and water conservation and soil improvement on sloping land: Practical application - soil and water conservation. 3. doi
  45. (2003). The mechanical design process. doi
  46. (2002). The Nature and Properties of Soils.
  47. (1995). Tillage effects on corn production and soil physical conditions. doi
  48. (1981). Tillage for clod forming sandy loam soils in the semi arid climate of Botswana. Soil tillage research doi
  49. (2002). Tillage for rainfall concentration in dry farming reasons. MSc thesis,
  50. (2006). Tillage Research 86, 38-51. ___________________________________________________________________ Elias Kethobile
  51. (1998). Understanding and Controlling Soil Erosion by Rainfall. In
  52. (1983). Water Conservation: Canadian Prairies. In
  53. (1983). Water Conservation: Introduction. In
  54. (1983). Water Conservation: Northern Great Plains. In
  55. (1983). Water Conservation: Pacific Northwest. In
  56. (1983). Water Conservation: Pacific Southwest. In
  57. (1983). Water Conservation: Principles of Soil Water Flow, Evaporation and Evapotranspiration. In

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