Department of Economics Bapatla College of Arts & Science
a) Surface Irrigation: Just flooding water. About 90% of the irrigated areas in the world are by this method. b) Sprinkler Irrigation: Applying water under pressure. About 5 % of the irrigated areas are by this method. c) Drip or Trickle Irrigation: Applying water slowly to the soil ideally at the same rate with crop consumption. d) Sub-Surface Irrigation: Flooding water underground and allowing it to come up by capillarity to crop roots.
History of Indian irrigation: Three Phases and a Turning Point. Since 1975, Indian agriculture has emerged as the world’s largest user of groundwater to grow food and fibre. The groundwater boom is fired by population pressure on land and demands of intensive diversification of farming. India and Pakistan together lost over 5 million ha of canal irrigated areas; tubewells are canibalizing flow irrigation. Investing in flow irrigation under BAU is throwing good money after bad. India’s irrigation challenge is one of managing its sub-continental aquifer systems, a vast reservoir we have left unmanaged.
Community was the unit of irrigation management Rainfall and Soil moisture Flow irrigation from tanks, canals, rivers Lift irrigation from wells and surface sources % of water consumptively used in agriculture % Contribution to aggregate Farm output and incomes
State emerged as the architect, builder, manager of irrigation Soil moisture management Flow irrigation from tanks, canals, rivers Lift irrigation from wells & surface sources % water consumptively used in agriculture % Contribution to aggregate Farm output and incomes
Individual farmer as the irrigation manager Soil moisture management Flow irrigation Pump irrigation from wells, tubewells, canals % of water consumptively used in agriculture % Contribution To Farm output & incomes
India has over 20 million irrigation wells. We add 0.8 million/year. Every fourth cultivator owns an irrigation well; non- owners depend on groundwater markets.
KharifRabi pumpflowpumpflow cereals64.336.177.822.2 pulses68.631.466.333.7 oilseeds78.821.272.727.3 mixed crops220.127.116.112.3 sugarcane81.918.18614 other crops65.534.582.817.2 vegetables67.432.674.926.1 fruit and nuts81.918.183.916.1 plantation72.727.372.927.1 fibre crops70.470.429.686.513.5 fodder79.720.386.913.1 other crops84.715.359.241.8 all693176.523.5 National Sample Survey, 2003, 59 th round:Proportion of area under different irrigated crops Served by pump and flow irrigation Groundwater share in irrigated Areas 70% and rising Govt. numbers Suggest 60% Irrigated areas Depend on GW, But…
60% of tubewells in use Were made during the 1990’s; numbers are Still accelerating.. Throughout the world, intensive groundwater irrigation is a response to water scarcity. Not in South Asia. Here, it is a response to scarcity of farm lands. The rise of a ‘water-scavenging’ irrigation economy..
Canal and tank irrigated areas condemned to low- value crops unresponsive to precision irrigation. Much diversification is Occurring outside Command areas (IFPRI). Much diversification Requires small dozes of Year-round, on-demand Irrigation. Value added farming Will expand with Waste-water irrigation and Groundwater. Our irrigation planning is preoccupied with food grains; Indian farmer is diversifying in a hurry.
Pump irrigation is cannibalizing flow irrigation. Irrigation systems are unable to Support groundwater irrigation This process has gathered Momentum since 1995 Throughout South Asia, surface irrigation is giving Way to pump irrigation. India, Pakistan and B’desh Lost 5.5 m ha of surface irrigation during 1994-2001
Mismatch between ground and surface irrigation in India: 578 districts covered by Minor Irrigation Cesus 2001 (GoI 2005) Line of hydrologic equilibrium Effective conjunctive management Means more well irrigation in command Areas. In Indian districts, the situation is the opposite. Only 12% of India’s wells are In command areas; and this Proportion is dropping every year
Recognize and respond to the new reality. Government’s role as irrigation provider is no longer the most critical. Investing in surface irrigation is throwing good money after bad.. Irrigation reforms around PIM are doomed to failure because flow irrigation itself is ebbing.. Irrigation Department’s mission statement needs to be rewritten.
Surface water dams deliver 150 km3/year; aquifer system delivers 220 km3/year which is far more productive. Managing the sub-continental system of aquifers ought to be India’s top priority; but this is nobody’s concern. India gets 4000 km3 of precipitation; we use 220 km3 of groundwater. Nature itself puts 4-10% of rainfall into aquifers. If we focus recharge effort at the right places, sustaining groundwater irrigation is possible. The challenge is to increase recharge in arid areas (north-west) and hardrock aquifers (peninsular India).
We need new institutional models to arrest erosion of public irrigation commands. What Indian farmer demands is on-farm water he can scavenge at will for high frequency precision-irrigation; wells will always score on canals and tanks. Rajasthan’s program of lined farm ponds on Indira Gandhi Nahar Yojana: canal water fill up the pond every 21 days; farmer run sprinklers with it. Gujarat government’s new scheme to create local irrigation entrepreneurs who will lay drip-irrigation infrastructure and operate an irrigation service from public canals. Maharashtra’s experiments in Northern Krishna basin.
Accelerate agricultural diversification Embrace and propagate water saving farming systems: aerobic rice, System of Rice Intensification, Zero-tillage, alternate wet-and-dry irrigation. Reform micro-irrigation subsidies that shrink drip-and- sprinkler equipment market instead of expanding it.
Evolve a practical, implementable tool-kit for groundwater management. Groundwater laws are unenforceable; pricing is impractial; GW Authority’s writ does not run in the country-side. Indirect instruments: Punjab’s experiment with electricity supply and rice procurement schedules to shift rice transplanting. Gujarat’s Jyotirgram Yojana of rationing quality power to farmers for irrigation;