Modules on Sustainable Agriculture MOSA Water http www

Modules on Sustainable Agriculture MOSA Water http: //www. howtostructurewater. net/ http: //www 1. lsbu. ac. uk/water_m

Keywords • The nexus: water – energy – food/fibre (agriculture) • Agriculture, the greatest user of water • Watershed (management) • Water scarcity, Water efficiency • Water harvesting, Water storage • Water quality, Water pollution • Erosion 2

Some importance of water ? 3

Some importance of water • Serves as habitat to some • Domestic and industrial organisms purposes • Support for organisms • Recreation • Vital component of the body • Reproduction • Transportation • Agriculture • Generation of energy • Temperature regulation 4

§ More than 840, 000 die each year because of water related diseases § More than 750 million people lack access to clean water with about 350 million from Africa § About 70% of water is withdrawn from aquifers, streams and lakes by agriculture § Adult human body averaged ~65% water http: //www. data 360. org/dsg. aspx? Data_Set_Group_Id=757 http: //water. org/water-crisis/waterfacts/water/ 5

The nexus: water – energy - food/fibre (agriculture) Source. www. wbscd. org 6

Typical sources of agricultural water: § Surface water • Rivers, streams, and irrigation ditches • Open canals • Impounded water such as ponds, reservoirs, and lakes § Groundwater from wells § Rainwater § Locally collected water such as in cisterns and rain barrels 7

Source: Gleick, P. H. , 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York, vol. 2 8

1 Water as a resource https: //www. youtube. com/watch? v=k. NQ 3 m 9 xymwo 9

Water food security Food production needs to increase by 60% by 2050 to satisfy the demand of a population of more than 9 billion people. (FAO, Coping with Water Scarcity , 2012) 10

Already by 2025, 1. 8 billion people will be living in countries or regions with absolute water scarcity, and two thirds of the world population could live under water stress conditions. (UN Water, 2013) Source: World Water Development Report 4, World Water Assessment Programme (WWAP), March 2012 11

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The Challenge http: //ecowatch. com/wpcontent/uploads/2013/12/dro ught. FI. jpg How to reduce withdrawals from water resources for agriculture while at the same time increasing agricultural production and maintaining essential environmental flows? In other words: Slide adapted from Walter Huppert How to promote sustainable enhancement of systemic water productivity in agriculture: on the field and in the water catchments? 13

Crop water need “[…] The crop water need (ET crop) is defined as the depth (or amount) of water needed to meet the water loss through evapotranspiration. In other words, it is the amount of water needed by the various crops to grow optimally[…]. ” ET crop = crop evapotranspiration = crop water need Reference: Irrigation Water Management: Irrigation water needs, Training Manual No. 3, FAO 14

http: //www. nature. com/scitable/knowledge/library/water-uptake-and-transport-in-vascular-plants 103016037 15

Source: D. Molden (ed. ) Water for Food, Water for Life (IWMI, 2007) 16

Water Budgeting an integrated approach To use water judiciously for humans, agriculture and livestock with a view to optimizing benefits in a context of climate variability, erratic rainfall and possible drought à Equitable sharing à More crop per drop http: //www. wotr. org/water-budgeting 17

Soil and water conservationsustainable water use 18

Source: Dupriez & de Leener 19

Example: Watershed management in Ethiopia Source: Friederike Kraemer VIDEO: https: //www. youtube. com/watch? v=nak-UUZnv. PI 20

Soil and water conservation (SWC) – main points Technical principles of conservation: • Reducing the erosive power of the rain drops by keeping the soil covered (with vegetation or mulch). • Fight erosion at its source and retain water where it falls (facilitate infiltration) • Reducing the speed of the water flowing down on slopes with the help of constructions. Organisational aspects: • SWC requires a collective action • Catchment approach and village landuse planning Institutional support GTZ 21

Technologies of erosion control Biological methods: • Contour planting of crops, mixed cropping and mulching • Vegetation strips along contour lines (on gentle slopes) GTZ Mechanical methods: • Terrassing (on steeper slopes) • Infiltration ditches along contour lines • Earth bunds that retains surface water • Stone bunds that allow water to permeate but reduce flow velocity considerably 22

Increasing the infiltration Contour trenches Semi-circular bunds Agromisa 2002 Circular bunds Agromisa 2002 Plant pits with mulch Agromisa 2002 23

Water harvesting in practice: Water-spreading weirs for the development of degraded dry river beds Photo by H. Bender: Tahoua region, Niger ! Source: Betifor, Water-spreading weirs for the development of degraded dry river valleys. giz/kfw 2010 24

Water harvesting in practice: http: //www. searnet. net/fileadmin/Experiences_in_promoting_In. Situ_RW_technologies. pdf 25

? How to keep the water in the soil? Q: Soil organic matter acts as? ? A: A storage of water, just like a sponge. Q: Mulch or plant cover crops reduce and increase? ? A: Reduce evaporation and increase infiltration. Q: Shallow digging of the dry top soil helps for what? ? http: //static 1. 1. sqspcdn. com/static/f/11 17046/26240812/1432036385050/wat er+loss_2. jpg? token=n. Xd. O 3 b. JZd 3 Uh Xk 2 HR 7 u. Qpqq. Xjro%3 D A: to reduce the dry up of the soil layers beneath. 26

2. 2 Irrigation 27

Irrigation water requirement depends on ? Source: Aquastat, FAO 28

4 Types of irrigation systems • Surface irrigation • Subsurface irrigation • Sprinkler irrigation • Drip irrigation Depending on natural conditions type of crop type of technology previous experience with irrigation required labor inputs costs and benefits http: //nrcca. cals. cornell. edu/soi l/CA 3/CA 0324. php 29

Drip Irrigation Low cost systems Plastic bottles – simple and very efficient Kotschi 30

Water pollution Source: lujiamin. wordpress. com 31

Keywords as a summary • The nexus: water – energy – food/fibre (agriculture) • Agriculture, the greatest user of water • Water scarcity calls for water efficiency • Water harvesting and Water storage become important • Agriculture depends on Water quality but also pollutants 32

Important aspects of sustainable water use in agriculture? What do you consider unsustainable? Which uses will be most affected by climate change? http: //www. langevin. com/blog/2013/08/29/3 -ways-to-maximize-brainstorming 33

References world business council for sustainable development: Water and energy linkages to food, feed, fibre. Online available at: http: //www. wbcsd. org/work-program/sectorprojects/waterenergyfood. aspx Gleick, P. H. , (several), available at: http: //pacinst. org Clay, J. (2004), World Agriculture and the Environment: A Commodity-by-Commodity Guide to Impacts and Practices, Island Press World Water Development Report 4 (March 2012), World Water Assessment Programme (WWAP) Irrigation Water Management: Irrigation water needs, Training Manual No. 1 and 3, FAO, available at: ftp: //ftp. fao. org/aglw/fwm/Manual 1. pdf or. . . Manual 3. pdf Mekdashi Studer, R. et al. (2013), Water harvesting, Guidelines to good practice, CDE et al. Molden, D. (2007), Water for Food, Water for Life: A comprehensive Assessment of Water Management in Agriculture, Earthscan Aquastat, FAO, available at: http: //www. fao. org/nr/water/aquastat/main/index. stm Agriwaterpedia at: http: //agriwaterpedia. info/wiki/Main_Page http: //www. nature. com/news/agriculture-increase-water-harvesting-in-africa-1. 1711634