1 / 10

Irrigation, productivity and the future

Irrigation, productivity and the future. Global irrigation in early 1990’s: 16% of total cropland 36% of total harvest Irrigation’s contribution to increased production (seeds, water, fertilisers, agrochemicals)

pembroke
Download Presentation

Irrigation, productivity and the future

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Irrigation, productivity and the future • Global irrigation in early 1990’s: • 16% of total cropland • 36% of total harvest • Irrigation’s contribution to increased production • (seeds, water, fertilisers, agrochemicals) • Uses about 65% of total available freshwater, and expected to decline to 60%in Y2K.

  2. Irrigation, productivity and the future (contd) • Contributed more than 1/2 of productivity gains since 1970 • Asia:2/3 of food supply from <1/2 of cultivated area. • 40% of all agricultural production from 20% of arable land in developing countries (Seregeldin 1996) • 46% grain, 57% total value of wheat and rice in developing countries produced under irrigation in 1990. • See overhead of production and arable area

  3. The future of irrigation? • 1960- 1980: buoyant investment in irrigation projects • (high yielding varieties, and good grain prices) • between 1961 and 1982- £500 bn (‘95 prices) • However, there has been a decline in investment due to: • fall in grain prices • real costs of irrigation increased • thus low rates of return • low efficiencies of projects • growing competition for freshwater (65%) • environmental concerns • However, the need for irrigation projects remains

  4. The future of irrigation? • The future of large-scale funding seems to be giving priority funding the improvement of existing irrigation systems • However, the future of irrigation and water provision both seem to be intricately linked to the ability of agriculture to feed the human population • See overhead of human population and • overhead of water provision scenarios

  5. Choice of irrigation systems: (Is it worthwhile irrigating?) • climate and soils • topography • water supply • crop types • labour • legal aspects • Other issues: • farmer training available, pests, machinery: spares and mechanics?,

  6. Choice of irrigation systems: • climate and soils • topography • will affect choice of irrigation method, height of fields compared to water supply, use of pumps, levelling costs, • water supply • elevation, distance, quality, cost, quantity of water required is frequently underestimated, need to consider seasonal availability and maximum demand • crops • may have to introduce new crops- will they sell? • Is the price of crop > irrigation costs?

  7. Choice of irrigation systems: • labour • more intensive than rain-fed cultivation, small farms-little added labour, more tied to land • legal aspects • many countries have legislation governing the use of limited water resources, common rights, upstream uses • Other issues: • farmer training available, pests, machinery: spares and mechanics?,

  8. Soil and Water Conservation • “Runoff agriculture provides moisture by collecting surface/subsurface runoff where other sources are likely to too costly, unsustainable or damaging.“ • “Concentration of surface runoff for cultivation” • Effectively uses moisture that would otherwise go to waste (unavailable to agriculture) • Characteristics and advantages of runoff farming: • cheap to establish • uses local materials (remote areas) • a sustainable practice • improved harvest security • improved yields, more crops per year • improve quantity and quality of streamwater and groundwater recharge

  9. Soil and Water Conservation • Agronomic techniques • Mulching • plastic sheets underground • soil amendments • Fallowing • Conservation tillage • Mechanical techniques (devices that act as cross-slope barriers • trash lines • stone lines • wattling/staking • contour bunds, hillside ditches, soil pits, terraces

  10. Soil and Water Conservation • Vegetative techniques • plant cover • agroforestry • Fog and mist harvesting • 150-750 litres per day from 48m2 mesh trap • Further reading: • Barrow 1987 • Hillel 1997 • Stern 1979

More Related