Water Management and Irrigation PDF

1 Water management Major Components 2 Why to manage water? Shortage of water Deficit of rainfall Excess of water Intensive cropping Different water Different crop water schedule requirement...

1 Water management Major Components 2 Why to manage water? Shortage of water Deficit of rainfall Excess of water Intensive cropping Different water Different crop water schedule requirement 3  Water Management Practices 1. On Farm Water Management a. Watercourse improvement b. High Efficiency IS 2. Soil Management a. Laser Land Leveling b. Mulching c. Use of organic matter 3. Crop Management a. Sowing method b. Weed control c. Suitable plant species Water course improvement: - building of lined irrigation canal structures - Building of DAMS and watersheds High Efficiency Irrigation System - Clearing trees, shrubs, and vegetation along watercourses - Repair and renovation of canal structures - Plugging out of water abstractions Laser Land Levelling - Machine that uses laser to asses land topography for surface levelling Mulching Mulch is a material that is spread over the ground as cover. Can be either organic (wood chips, fallen leaves, straw, saw dust, etc.) or inorganic (black plastic, rocks, etc) Advantages of mulching: - minimize evaporation - Prevents growth of weeds - For organic – adds nutrients to the soil, helps to retain water for plant consumption Use of organic matter - Adds nutrients to the soil minus the negative effect of fertilizers from inorganic 4  additives Sowing Methods -Broadcasting – most common and oldest methods of seed sowing where seeds are just spread on the soil, may or may not be covered, may be done manually with hands or through mechanical spreader Advantages - Cheap - Take less time - Suitable for smack seeded plants and plants with small planting distance Disadvantages - Uneven seed distribution - Some seeds are not covered by soil - Non-uniform seed germination - Affected crop stand - Dibbling - process in which seeds are placed in holes or pits at equal predetermined distances and depths Advantages - Required less seeds - Rapid and uniform germination - Good seedling vigor Disadvantages - Time consuming - Required more labor - Costly - Drilling – seeds are drop into holes then covered and compacted the soil. Done with the help of seed drill. Advantages - Required less quantity of seeds because seeds are metered by the device - Manures, fertilizers and amendments can be applied with seeds during drilling Disadvantages - Time consuming - More labor required - High cost - Manual Planting – placing seeds, propagules, or seedlings firmly in the soil for germination and growth with out using any machines and implements - Transplanting - planting of seedlings in main field after pulling out from the nursery, can be manual or by transplanting machine Weed Control - Removal of undesirable vegetation and noxious weeds that is competing with 4  desired crops Bad cause of Weeds -reduce crop yield because of nutrient competition against weeds - Increase production cost - May harbor insects and diseases that attack crop plants Suitable plant species - Selection of suitable plant species for a certain condition ensures proper growth for plants 4 Scope of Irrigation Irrigation water is delivered from water source (watersheds)to the farm and to drainage channels. Concept of Irrigation The amount of crop water requirement is not the same as the amount of irrigation water that the plant requires per second. - CWR – crop water requirement 𝑪𝑾𝑹 = 𝑬𝑻 + 𝑷𝑳 + 𝑭𝑳 - ET – evapotranspiration - PL – percolation losses - FL – field losses 𝑰𝑾𝑹 = 𝑪𝑾𝑹 − 𝑬𝑹 - IWR – Irrigation water requirement - ER - Effective rainfall 5 Purpose of Irrigation 1. Supply the soil moisture 4. Wash out dilute acids in the 2. Cool the soil and atmosphere soil 3. Provide insurance of crop 5. Reduce hazard of soil piping against drought 6. Soften soil hard pan 6  Types of Irrigation Systems in the Philippines National Irrigation Systems (NIS) Large and medium schemes Manage by National Irrigation Administration (NIA) 7 Communal Irrigation Systems (NIS) Small-scale schemes Constructed with participation of farmer- beneficiaries thru IA’s Operated and maintenance by IA’s 8 Private Irrigation Systems (NIS) Constructed, operated and maintained by private individual or groups for personal use with or without NIA assistance 9  National Irrigation Communal Irrigation Description System System Service Area More than 1000 ha Less than 1000 ha Implementation/ NIA NIA with farmers’ Construction participation Operation and NIA and Irrigators Irrigators Association maintenance Associations Farmers pay irrigation Farmers pay Water charges service fee per amortization hectares/season/crop Purpose of water Capital cost recovery Capital cost recovery charges 10 Types of Scheme of Development 1. Diversion Projects - entail drawing of water 2. Reservoir projects watershed - involves the construction of storage dams for impounding of water DAM - barrier that stops or restricts the flow of surface water or underground streams - multipurpose 3. Pump projects - water is lifted from the water source 11 Agriculture as a Dominant Water User Agriculture 60 – 70% Sector Industries 20% Human/ sanitation 8-10% * world’s fresh water 12